diff --git a/libs/ultrahdr/gainmapmath.cpp b/libs/ultrahdr/gainmapmath.cpp
index 37c3cf3..ee15363 100644
--- a/libs/ultrahdr/gainmapmath.cpp
+++ b/libs/ultrahdr/gainmapmath.cpp
@@ -119,34 +119,39 @@
     return (value < 0.0f) ? 0.0f : (value > kMaxPixelFloat) ? kMaxPixelFloat : value;
 }
 
-// See IEC 61966-2-1, Equation F.7.
+// See IEC 61966-2-1/Amd 1:2003, Equation F.7.
 static const float kSrgbR = 0.2126f, kSrgbG = 0.7152f, kSrgbB = 0.0722f;
 
 float srgbLuminance(Color e) {
   return kSrgbR * e.r + kSrgbG * e.g + kSrgbB * e.b;
 }
 
-// See ECMA TR/98, Section 7.
-static const float kSrgbRCr = 1.402f, kSrgbGCb = 0.34414f, kSrgbGCr = 0.71414f, kSrgbBCb = 1.772f;
-
-Color srgbYuvToRgb(Color e_gamma) {
-  return {{{ clampPixelFloat(e_gamma.y + kSrgbRCr * e_gamma.v),
-             clampPixelFloat(e_gamma.y - kSrgbGCb * e_gamma.u - kSrgbGCr * e_gamma.v),
-             clampPixelFloat(e_gamma.y + kSrgbBCb * e_gamma.u) }}};
-}
-
-// See ECMA TR/98, Section 7.
-static const float kSrgbYR = 0.299f, kSrgbYG = 0.587f, kSrgbYB = 0.114f;
-static const float kSrgbUR = -0.1687f, kSrgbUG = -0.3313f, kSrgbUB = 0.5f;
-static const float kSrgbVR = 0.5f, kSrgbVG = -0.4187f, kSrgbVB = -0.0813f;
+// See ITU-R BT.709-6, Section 3.
+// Uses the same coefficients for deriving luma signal as
+// IEC 61966-2-1/Amd 1:2003 states for luminance, so we reuse the luminance
+// function above.
+static const float kSrgbCb = 1.8556f, kSrgbCr = 1.5748f;
 
 Color srgbRgbToYuv(Color e_gamma) {
-  return {{{ kSrgbYR * e_gamma.r + kSrgbYG * e_gamma.g + kSrgbYB * e_gamma.b,
-             kSrgbUR * e_gamma.r + kSrgbUG * e_gamma.g + kSrgbUB * e_gamma.b,
-             kSrgbVR * e_gamma.r + kSrgbVG * e_gamma.g + kSrgbVB * e_gamma.b }}};
+  float y_gamma = srgbLuminance(e_gamma);
+  return {{{ y_gamma,
+             (e_gamma.b - y_gamma) / kSrgbCb,
+             (e_gamma.r - y_gamma) / kSrgbCr }}};
 }
 
-// See IEC 61966-2-1, Equations F.5 and F.6.
+// See ITU-R BT.709-6, Section 3.
+// Same derivation to BT.2100's YUV->RGB, below. Similar to srgbRgbToYuv, we
+// can reuse the luminance coefficients since they are the same.
+static const float kSrgbGCb = kSrgbB * kSrgbCb / kSrgbG;
+static const float kSrgbGCr = kSrgbR * kSrgbCr / kSrgbG;
+
+Color srgbYuvToRgb(Color e_gamma) {
+  return {{{ clampPixelFloat(e_gamma.y + kSrgbCr * e_gamma.v),
+             clampPixelFloat(e_gamma.y - kSrgbGCb * e_gamma.u - kSrgbGCr * e_gamma.v),
+             clampPixelFloat(e_gamma.y + kSrgbCb * e_gamma.u) }}};
+}
+
+// See IEC 61966-2-1/Amd 1:2003, Equations F.5 and F.6.
 float srgbInvOetf(float e_gamma) {
   if (e_gamma <= 0.04045f) {
     return e_gamma / 12.92f;
@@ -178,13 +183,38 @@
 ////////////////////////////////////////////////////////////////////////////////
 // Display-P3 transformations
 
-// See SMPTE EG 432-1, Table 7-2.
+// See SMPTE EG 432-1, Equation 7-8.
 static const float kP3R = 0.20949f, kP3G = 0.72160f, kP3B = 0.06891f;
 
 float p3Luminance(Color e) {
   return kP3R * e.r + kP3G * e.g + kP3B * e.b;
 }
 
+// See ITU-R BT.601-7, Sections 2.5.1 and 2.5.2.
+// Unfortunately, calculation of luma signal differs from calculation of
+// luminance for Display-P3, so we can't reuse p3Luminance here.
+static const float kP3YR = 0.299f, kP3YG = 0.587f, kP3YB = 0.114f;
+static const float kP3Cb = 1.772f, kP3Cr = 1.402f;
+
+Color p3RgbToYuv(Color e_gamma) {
+  float y_gamma = kP3YR * e_gamma.r + kP3YG * e_gamma.g + kP3YB * e_gamma.b;
+  return {{{ y_gamma,
+             (e_gamma.b - y_gamma) / kP3Cb,
+             (e_gamma.r - y_gamma) / kP3Cr }}};
+}
+
+// See ITU-R BT.601-7, Sections 2.5.1 and 2.5.2.
+// Same derivation to BT.2100's YUV->RGB, below. Similar to p3RgbToYuv, we must
+// use luma signal coefficients rather than the luminance coefficients.
+static const float kP3GCb = kP3YB * kP3Cb / kP3YG;
+static const float kP3GCr = kP3YR * kP3Cr / kP3YG;
+
+Color p3YuvToRgb(Color e_gamma) {
+  return {{{ clampPixelFloat(e_gamma.y + kP3Cr * e_gamma.v),
+             clampPixelFloat(e_gamma.y - kP3GCb * e_gamma.u - kP3GCr * e_gamma.v),
+             clampPixelFloat(e_gamma.y + kP3Cb * e_gamma.u) }}};
+}
+
 
 ////////////////////////////////////////////////////////////////////////////////
 // BT.2100 transformations - according to ITU-R BT.2100-2
@@ -197,6 +227,8 @@
 }
 
 // See ITU-R BT.2100-2, Table 6, Derivation of colour difference signals.
+// BT.2100 uses the same coefficients for calculating luma signal and luminance,
+// so we reuse the luminance function here.
 static const float kBt2100Cb = 1.8814f, kBt2100Cr = 1.4746f;
 
 Color bt2100RgbToYuv(Color e_gamma) {
@@ -206,6 +238,10 @@
              (e_gamma.r - y_gamma) / kBt2100Cr }}};
 }
 
+// See ITU-R BT.2100-2, Table 6, Derivation of colour difference signals.
+//
+// Similar to bt2100RgbToYuv above, we can reuse the luminance coefficients.
+//
 // Derived by inversing bt2100RgbToYuv. The derivation for R and B are  pretty
 // straight forward; we just invert the formulas for U and V above. But deriving
 // the formula for G is a bit more complicated:
@@ -440,6 +476,85 @@
   }
 }
 
+// All of these conversions are derived from the respective input YUV->RGB conversion followed by
+// the RGB->YUV for the receiving encoding. They are consistent with the RGB<->YUV functions in this
+// file, given that we uses BT.709 encoding for sRGB and BT.601 encoding for Display-P3, to match
+// DataSpace.
+
+Color yuv709To601(Color e_gamma) {
+  return {{{ 1.0f * e_gamma.y +  0.101579f * e_gamma.u +  0.196076f * e_gamma.v,
+             0.0f * e_gamma.y +  0.989854f * e_gamma.u + -0.110653f * e_gamma.v,
+             0.0f * e_gamma.y + -0.072453f * e_gamma.u +  0.983398f * e_gamma.v }}};
+}
+
+Color yuv709To2100(Color e_gamma) {
+  return {{{ 1.0f * e_gamma.y + -0.016969f * e_gamma.u +  0.096312f * e_gamma.v,
+             0.0f * e_gamma.y +  0.995306f * e_gamma.u + -0.051192f * e_gamma.v,
+             0.0f * e_gamma.y +  0.011507f * e_gamma.u +  1.002637f * e_gamma.v }}};
+}
+
+Color yuv601To709(Color e_gamma) {
+  return {{{ 1.0f * e_gamma.y + -0.118188f * e_gamma.u + -0.212685f * e_gamma.v,
+             0.0f * e_gamma.y +  1.018640f * e_gamma.u +  0.114618f * e_gamma.v,
+             0.0f * e_gamma.y +  0.075049f * e_gamma.u +  1.025327f * e_gamma.v }}};
+}
+
+Color yuv601To2100(Color e_gamma) {
+  return {{{ 1.0f * e_gamma.y + -0.128245f * e_gamma.u + -0.115879f * e_gamma.v,
+             0.0f * e_gamma.y +  1.010016f * e_gamma.u +  0.061592f * e_gamma.v,
+             0.0f * e_gamma.y +  0.086969f * e_gamma.u +  1.029350f * e_gamma.v }}};
+}
+
+Color yuv2100To709(Color e_gamma) {
+  return {{{ 1.0f * e_gamma.y +  0.018149f * e_gamma.u + -0.095132f * e_gamma.v,
+             0.0f * e_gamma.y +  1.004123f * e_gamma.u +  0.051267f * e_gamma.v,
+             0.0f * e_gamma.y + -0.011524f * e_gamma.u +  0.996782f * e_gamma.v }}};
+}
+
+Color yuv2100To601(Color e_gamma) {
+  return {{{ 1.0f * e_gamma.y +  0.117887f * e_gamma.u +  0.105521f * e_gamma.v,
+             0.0f * e_gamma.y +  0.995211f * e_gamma.u + -0.059549f * e_gamma.v,
+             0.0f * e_gamma.y + -0.084085f * e_gamma.u +  0.976518f * e_gamma.v }}};
+}
+
+void transformYuv420(jr_uncompressed_ptr image, size_t x_chroma, size_t y_chroma,
+                     ColorTransformFn fn) {
+  Color yuv1 = getYuv420Pixel(image, x_chroma * 2,     y_chroma * 2    );
+  Color yuv2 = getYuv420Pixel(image, x_chroma * 2 + 1, y_chroma * 2    );
+  Color yuv3 = getYuv420Pixel(image, x_chroma * 2,     y_chroma * 2 + 1);
+  Color yuv4 = getYuv420Pixel(image, x_chroma * 2 + 1, y_chroma * 2 + 1);
+
+  yuv1 = fn(yuv1);
+  yuv2 = fn(yuv2);
+  yuv3 = fn(yuv3);
+  yuv4 = fn(yuv4);
+
+  Color new_uv = (yuv1 + yuv2 + yuv3 + yuv4) / 4.0f;
+
+  size_t pixel_y1_idx =  x_chroma * 2      +  y_chroma * 2      * image->width;
+  size_t pixel_y2_idx = (x_chroma * 2 + 1) +  y_chroma * 2      * image->width;
+  size_t pixel_y3_idx =  x_chroma * 2      + (y_chroma * 2 + 1) * image->width;
+  size_t pixel_y4_idx = (x_chroma * 2 + 1) + (y_chroma * 2 + 1) * image->width;
+
+  uint8_t& y1_uint = reinterpret_cast<uint8_t*>(image->data)[pixel_y1_idx];
+  uint8_t& y2_uint = reinterpret_cast<uint8_t*>(image->data)[pixel_y2_idx];
+  uint8_t& y3_uint = reinterpret_cast<uint8_t*>(image->data)[pixel_y3_idx];
+  uint8_t& y4_uint = reinterpret_cast<uint8_t*>(image->data)[pixel_y4_idx];
+
+  size_t pixel_count = image->width * image->height;
+  size_t pixel_uv_idx = x_chroma + y_chroma * (image->width / 2);
+
+  uint8_t& u_uint = reinterpret_cast<uint8_t*>(image->data)[pixel_count + pixel_uv_idx];
+  uint8_t& v_uint = reinterpret_cast<uint8_t*>(image->data)[pixel_count * 5 / 4 + pixel_uv_idx];
+
+  y1_uint = static_cast<uint8_t>(floor(yuv1.y * 255.0f + 0.5f));
+  y2_uint = static_cast<uint8_t>(floor(yuv2.y * 255.0f + 0.5f));
+  y3_uint = static_cast<uint8_t>(floor(yuv3.y * 255.0f + 0.5f));
+  y4_uint = static_cast<uint8_t>(floor(yuv4.y * 255.0f + 0.5f));
+
+  u_uint = static_cast<uint8_t>(floor(new_uv.u * 255.0f + 128.0f + 0.5f));
+  v_uint = static_cast<uint8_t>(floor(new_uv.v * 255.0f + 128.0f + 0.5f));
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 // Gain map calculations
diff --git a/libs/ultrahdr/icc.cpp b/libs/ultrahdr/icc.cpp
index 32d08aa..1ab3c7c 100644
--- a/libs/ultrahdr/icc.cpp
+++ b/libs/ultrahdr/icc.cpp
@@ -14,6 +14,10 @@
  * limitations under the License.
  */
 
+#ifndef USE_BIG_ENDIAN
+#define USE_BIG_ENDIAN true
+#endif
+
 #include <ultrahdr/icc.h>
 #include <ultrahdr/gainmapmath.h>
 #include <vector>
@@ -540,13 +544,21 @@
     size_t tag_table_size = kICCTagTableEntrySize * tags.size();
     size_t profile_size = kICCHeaderSize + tag_table_size + tag_data_size;
 
+    sp<DataStruct> dataStruct = sp<DataStruct>::make(profile_size + kICCIdentifierSize);
+
+    // Write identifier, chunk count, and chunk ID
+    if (!dataStruct->write(kICCIdentifier, sizeof(kICCIdentifier)) ||
+        !dataStruct->write8(1) || !dataStruct->write8(1)) {
+        ALOGE("writeIccProfile(): error in identifier");
+        return dataStruct;
+    }
+
     // Write the header.
     header.data_color_space = Endian_SwapBE32(Signature_RGB);
     header.pcs = Endian_SwapBE32(tf == ULTRAHDR_TF_PQ ? Signature_Lab : Signature_XYZ);
     header.size = Endian_SwapBE32(profile_size);
     header.tag_count = Endian_SwapBE32(tags.size());
 
-    sp<DataStruct> dataStruct = sp<DataStruct>::make(profile_size);
     if (!dataStruct->write(&header, sizeof(header))) {
         ALOGE("writeIccProfile(): error in header");
         return dataStruct;
@@ -582,4 +594,84 @@
     return dataStruct;
 }
 
-} // namespace android::ultrahdr
\ No newline at end of file
+bool IccHelper::tagsEqualToMatrix(const Matrix3x3& matrix,
+                                  const uint8_t* red_tag,
+                                  const uint8_t* green_tag,
+                                  const uint8_t* blue_tag) {
+    sp<DataStruct> red_tag_test = write_xyz_tag(matrix.vals[0][0], matrix.vals[1][0],
+                                                matrix.vals[2][0]);
+    sp<DataStruct> green_tag_test = write_xyz_tag(matrix.vals[0][1], matrix.vals[1][1],
+                                                  matrix.vals[2][1]);
+    sp<DataStruct> blue_tag_test = write_xyz_tag(matrix.vals[0][2], matrix.vals[1][2],
+                                                 matrix.vals[2][2]);
+    return memcmp(red_tag, red_tag_test->getData(), kColorantTagSize) == 0 &&
+           memcmp(green_tag, green_tag_test->getData(), kColorantTagSize) == 0 &&
+           memcmp(blue_tag, blue_tag_test->getData(), kColorantTagSize) == 0;
+}
+
+ultrahdr_color_gamut IccHelper::readIccColorGamut(void* icc_data, size_t icc_size) {
+    // Each tag table entry consists of 3 fields of 4 bytes each.
+    static const size_t kTagTableEntrySize = 12;
+
+    if (icc_data == nullptr || icc_size < sizeof(ICCHeader) + kICCIdentifierSize) {
+        return ULTRAHDR_COLORGAMUT_UNSPECIFIED;
+    }
+
+    if (memcmp(icc_data, kICCIdentifier, sizeof(kICCIdentifier)) != 0) {
+        return ULTRAHDR_COLORGAMUT_UNSPECIFIED;
+    }
+
+    uint8_t* icc_bytes = reinterpret_cast<uint8_t*>(icc_data) + kICCIdentifierSize;
+
+    ICCHeader* header = reinterpret_cast<ICCHeader*>(icc_bytes);
+
+    // Use 0 to indicate not found, since offsets are always relative to start
+    // of ICC data and therefore a tag offset of zero would never be valid.
+    size_t red_primary_offset = 0, green_primary_offset = 0, blue_primary_offset = 0;
+    size_t red_primary_size = 0, green_primary_size = 0, blue_primary_size = 0;
+    for (size_t tag_idx = 0; tag_idx < Endian_SwapBE32(header->tag_count); ++tag_idx) {
+        uint32_t* tag_entry_start = reinterpret_cast<uint32_t*>(
+            icc_bytes + sizeof(ICCHeader) + tag_idx * kTagTableEntrySize);
+        // first 4 bytes are the tag signature, next 4 bytes are the tag offset,
+        // last 4 bytes are the tag length in bytes.
+        if (red_primary_offset == 0 && *tag_entry_start == Endian_SwapBE32(kTAG_rXYZ)) {
+            red_primary_offset = Endian_SwapBE32(*(tag_entry_start+1));
+            red_primary_size = Endian_SwapBE32(*(tag_entry_start+2));
+        } else if (green_primary_offset == 0 && *tag_entry_start == Endian_SwapBE32(kTAG_gXYZ)) {
+            green_primary_offset = Endian_SwapBE32(*(tag_entry_start+1));
+            green_primary_size = Endian_SwapBE32(*(tag_entry_start+2));
+        } else if (blue_primary_offset == 0 && *tag_entry_start == Endian_SwapBE32(kTAG_bXYZ)) {
+            blue_primary_offset = Endian_SwapBE32(*(tag_entry_start+1));
+            blue_primary_size = Endian_SwapBE32(*(tag_entry_start+2));
+        }
+    }
+
+    if (red_primary_offset == 0 || red_primary_size != kColorantTagSize ||
+        kICCIdentifierSize + red_primary_offset + red_primary_size > icc_size ||
+        green_primary_offset == 0 || green_primary_size != kColorantTagSize ||
+        kICCIdentifierSize + green_primary_offset + green_primary_size > icc_size ||
+        blue_primary_offset == 0 || blue_primary_size != kColorantTagSize ||
+        kICCIdentifierSize + blue_primary_offset + blue_primary_size > icc_size) {
+        return ULTRAHDR_COLORGAMUT_UNSPECIFIED;
+    }
+
+    uint8_t* red_tag = icc_bytes + red_primary_offset;
+    uint8_t* green_tag = icc_bytes + green_primary_offset;
+    uint8_t* blue_tag = icc_bytes + blue_primary_offset;
+
+    // Serialize tags as we do on encode and compare what we find to that to
+    // determine the gamut (since we don't have a need yet for full deserialize).
+    if (tagsEqualToMatrix(kSRGB, red_tag, green_tag, blue_tag)) {
+        return ULTRAHDR_COLORGAMUT_BT709;
+    } else if (tagsEqualToMatrix(kDisplayP3, red_tag, green_tag, blue_tag)) {
+        return ULTRAHDR_COLORGAMUT_P3;
+    } else if (tagsEqualToMatrix(kRec2020, red_tag, green_tag, blue_tag)) {
+        return ULTRAHDR_COLORGAMUT_BT2100;
+    }
+
+    // Didn't find a match to one of the profiles we write; indicate the gamut
+    // is unspecified since we don't understand it.
+    return ULTRAHDR_COLORGAMUT_UNSPECIFIED;
+}
+
+} // namespace android::ultrahdr
diff --git a/libs/ultrahdr/include/ultrahdr/gainmapmath.h b/libs/ultrahdr/include/ultrahdr/gainmapmath.h
index abc9356..13832db 100644
--- a/libs/ultrahdr/include/ultrahdr/gainmapmath.h
+++ b/libs/ultrahdr/include/ultrahdr/gainmapmath.h
@@ -218,24 +218,30 @@
 // except for those concerning transfer functions.
 
 /*
- * Calculate the luminance of a linear RGB sRGB pixel, according to IEC 61966-2-1.
+ * Calculate the luminance of a linear RGB sRGB pixel, according to
+ * IEC 61966-2-1/Amd 1:2003.
  *
  * [0.0, 1.0] range in and out.
  */
 float srgbLuminance(Color e);
 
 /*
- * Convert from OETF'd srgb YUV to RGB, according to ECMA TR/98.
+ * Convert from OETF'd srgb RGB to YUV, according to ITU-R BT.709-6.
+ *
+ * BT.709 YUV<->RGB matrix is used to match expectations for DataSpace.
+ */
+Color srgbRgbToYuv(Color e_gamma);
+
+
+/*
+ * Convert from OETF'd srgb YUV to RGB, according to ITU-R BT.709-6.
+ *
+ * BT.709 YUV<->RGB matrix is used to match expectations for DataSpace.
  */
 Color srgbYuvToRgb(Color e_gamma);
 
 /*
- * Convert from OETF'd srgb RGB to YUV, according to ECMA TR/98.
- */
-Color srgbRgbToYuv(Color e_gamma);
-
-/*
- * Convert from srgb to linear, according to IEC 61966-2-1.
+ * Convert from srgb to linear, according to IEC 61966-2-1/Amd 1:2003.
  *
  * [0.0, 1.0] range in and out.
  */
@@ -257,6 +263,20 @@
  */
 float p3Luminance(Color e);
 
+/*
+ * Convert from OETF'd P3 RGB to YUV, according to ITU-R BT.601-7.
+ *
+ * BT.601 YUV<->RGB matrix is used to match expectations for DataSpace.
+ */
+Color p3RgbToYuv(Color e_gamma);
+
+/*
+ * Convert from OETF'd P3 YUV to RGB, according to ITU-R BT.601-7.
+ *
+ * BT.601 YUV<->RGB matrix is used to match expectations for DataSpace.
+ */
+Color p3YuvToRgb(Color e_gamma);
+
 
 ////////////////////////////////////////////////////////////////////////////////
 // BT.2100 transformations - according to ITU-R BT.2100-2
@@ -269,12 +289,16 @@
 float bt2100Luminance(Color e);
 
 /*
- * Convert from OETF'd BT.2100 RGB to YUV.
+ * Convert from OETF'd BT.2100 RGB to YUV, according to ITU-R BT.2100-2.
+ *
+ * BT.2100 YUV<->RGB matrix is used to match expectations for DataSpace.
  */
 Color bt2100RgbToYuv(Color e_gamma);
 
 /*
- * Convert from OETF'd BT.2100 YUV to RGB.
+ * Convert from OETF'd BT.2100 YUV to RGB, according to ITU-R BT.2100-2.
+ *
+ * BT.2100 YUV<->RGB matrix is used to match expectations for DataSpace.
  */
 Color bt2100YuvToRgb(Color e_gamma);
 
@@ -358,6 +382,31 @@
  */
 ColorTransformFn getHdrConversionFn(ultrahdr_color_gamut sdr_gamut, ultrahdr_color_gamut hdr_gamut);
 
+/*
+ * Convert between YUV encodings, according to ITU-R BT.709-6, ITU-R BT.601-7, and ITU-R BT.2100-2.
+ *
+ * Bt.709 and Bt.2100 have well-defined YUV encodings; Display-P3's is less well defined, but is
+ * treated as Bt.601 by DataSpace, hence we do the same.
+ */
+Color yuv709To601(Color e_gamma);
+Color yuv709To2100(Color e_gamma);
+Color yuv601To709(Color e_gamma);
+Color yuv601To2100(Color e_gamma);
+Color yuv2100To709(Color e_gamma);
+Color yuv2100To601(Color e_gamma);
+
+/*
+ * Performs a transformation at the chroma x and y coordinates provided on a YUV420 image.
+ *
+ * Apply the transformation by determining transformed YUV for each of the 4 Y + 1 UV; each Y gets
+ * this result, and UV gets the averaged result.
+ *
+ * x_chroma and y_chroma should be less than or equal to half the image's width and height
+ * respecitively, since input is 4:2:0 subsampled.
+ */
+void transformYuv420(jr_uncompressed_ptr image, size_t x_chroma, size_t y_chroma,
+                     ColorTransformFn fn);
+
 
 ////////////////////////////////////////////////////////////////////////////////
 // Gain map calculations
diff --git a/libs/ultrahdr/include/ultrahdr/icc.h b/libs/ultrahdr/include/ultrahdr/icc.h
index 7f6ab88..7f047f8 100644
--- a/libs/ultrahdr/include/ultrahdr/icc.h
+++ b/libs/ultrahdr/include/ultrahdr/icc.h
@@ -56,12 +56,16 @@
     Signature_XYZ  = 0x58595A20,
 };
 
-
 typedef uint32_t FourByteTag;
 static inline constexpr FourByteTag SetFourByteTag(char a, char b, char c, char d) {
     return (((uint32_t)a << 24) | ((uint32_t)b << 16) | ((uint32_t)c << 8) | (uint32_t)d);
 }
 
+static constexpr char kICCIdentifier[] = "ICC_PROFILE";
+// 12 for the actual identifier, +2 for the chunk count and chunk index which
+// will always follow.
+static constexpr size_t kICCIdentifierSize = 14;
+
 // This is equal to the header size according to the ICC specification (128)
 // plus the size of the tag count (4).  We include the tag count since we
 // always require it to be present anyway.
@@ -70,6 +74,10 @@
 // Contains a signature (4), offset (4), and size (4).
 static constexpr size_t kICCTagTableEntrySize = 12;
 
+// size should be 20; 4 bytes for type descriptor, 4 bytes reserved, 12
+// bytes for a single XYZ number type (4 bytes per coordinate).
+static constexpr size_t kColorantTagSize = 20;
+
 static constexpr uint32_t kDisplay_Profile    = SetFourByteTag('m', 'n', 't', 'r');
 static constexpr uint32_t kRGB_ColorSpace     = SetFourByteTag('R', 'G', 'B', ' ');
 static constexpr uint32_t kXYZ_PCSSpace       = SetFourByteTag('X', 'Y', 'Z', ' ');
@@ -225,10 +233,23 @@
     static void compute_lut_entry(const Matrix3x3& src_to_XYZD50, float rgb[3]);
     static sp<DataStruct> write_clut(const uint8_t* grid_points, const uint8_t* grid_16);
 
+    // Checks if a set of xyz tags is equivalent to a 3x3 Matrix. Each input
+    // tag buffer assumed to be at least kColorantTagSize in size.
+    static bool tagsEqualToMatrix(const Matrix3x3& matrix,
+                                  const uint8_t* red_tag,
+                                  const uint8_t* green_tag,
+                                  const uint8_t* blue_tag);
+
 public:
+    // Output includes JPEG embedding identifier and chunk information, but not
+    // APPx information.
     static sp<DataStruct> writeIccProfile(const ultrahdr_transfer_function tf,
                                           const ultrahdr_color_gamut gamut);
+    // NOTE: this function is not robust; it can infer gamuts that IccHelper
+    // writes out but should not be considered a reference implementation for
+    // robust parsing of ICC profiles or their gamuts.
+    static ultrahdr_color_gamut readIccColorGamut(void* icc_data, size_t icc_size);
 };
 }  // namespace android::ultrahdr
 
-#endif //ANDROID_ULTRAHDR_ICC_H
\ No newline at end of file
+#endif //ANDROID_ULTRAHDR_ICC_H
diff --git a/libs/ultrahdr/include/ultrahdr/jpegdecoderhelper.h b/libs/ultrahdr/include/ultrahdr/jpegdecoderhelper.h
index 4f2b742..8b5499a 100644
--- a/libs/ultrahdr/include/ultrahdr/jpegdecoderhelper.h
+++ b/libs/ultrahdr/include/ultrahdr/jpegdecoderhelper.h
@@ -83,11 +83,14 @@
      */
     size_t getEXIFSize();
     /*
-     * Returns the position offset of EXIF package
-     * (4 bypes offset to FF sign, the byte after FF E1 XX XX <this byte>),
-     * or -1  if no EXIF exists.
+     * Returns the ICC data from the image.
      */
-    int getEXIFPos() { return mExifPos; }
+    void* getICCPtr();
+    /*
+     * Returns the decompressed ICC buffer size. This method must be called only after
+     * calling decompressImage() or getCompressedImageParameters().
+     */
+    size_t getICCSize();
     /*
      * Decompresses metadata of the image. All vectors are owned by the caller.
      */
@@ -112,12 +115,12 @@
     std::vector<JOCTET> mXMPBuffer;
     // The buffer that holds EXIF Data.
     std::vector<JOCTET> mEXIFBuffer;
+    // The buffer that holds ICC Data.
+    std::vector<JOCTET> mICCBuffer;
 
     // Resolution of the decompressed image.
     size_t mWidth;
     size_t mHeight;
-    // Position of EXIF package, default value is -1 which means no EXIF package appears.
-    size_t mExifPos;
 };
 } /* namespace android::ultrahdr  */
 
diff --git a/libs/ultrahdr/include/ultrahdr/jpegr.h b/libs/ultrahdr/include/ultrahdr/jpegr.h
index 1f9bd0f..9546ca4 100644
--- a/libs/ultrahdr/include/ultrahdr/jpegr.h
+++ b/libs/ultrahdr/include/ultrahdr/jpegr.h
@@ -125,7 +125,7 @@
      *
      * Generate gain map from the HDR and SDR inputs, compress SDR YUV to 8-bit JPEG and append
      * the gain map to the end of the compressed JPEG. HDR and SDR inputs must be the same
-     * resolution.
+     * resolution. SDR input is assumed to use the sRGB transfer function.
      * @param uncompressed_p010_image uncompressed HDR image in P010 color format
      * @param uncompressed_yuv_420_image uncompressed SDR image in YUV_420 color format
      * @param hdr_tf transfer function of the HDR image
@@ -152,7 +152,9 @@
      * This method requires HAL Hardware JPEG encoder.
      *
      * Generate gain map from the HDR and SDR inputs, append the gain map to the end of the
-     * compressed JPEG. HDR and SDR inputs must be the same resolution and color space.
+     * compressed JPEG. Adds an ICC profile if one isn't present in the input JPEG image. HDR and
+     * SDR inputs must be the same resolution and color space. SDR image is assumed to use the sRGB
+     * transfer function.
      * @param uncompressed_p010_image uncompressed HDR image in P010 color format
      * @param uncompressed_yuv_420_image uncompressed SDR image in YUV_420 color format
      *                                   Note: the SDR image must be the decoded version of the JPEG
@@ -178,8 +180,9 @@
      * This method requires HAL Hardware JPEG encoder.
      *
      * Decode the compressed 8-bit JPEG image to YUV SDR, generate gain map from the HDR input
-     * and the decoded SDR result, append the gain map to the end of the compressed JPEG. HDR
-     * and SDR inputs must be the same resolution.
+     * and the decoded SDR result, append the gain map to the end of the compressed JPEG. Adds an
+     * ICC profile if one isn't present in the input JPEG image. HDR and SDR inputs must be the same
+     * resolution. JPEG image is assumed to use the sRGB transfer function.
      * @param uncompressed_p010_image uncompressed HDR image in P010 color format
      * @param compressed_jpeg_image compressed 8-bit JPEG image
      * @param hdr_tf transfer function of the HDR image
@@ -198,7 +201,8 @@
      * Encode API-4
      * Assemble JPEGR image from SDR JPEG and gainmap JPEG.
      *
-     * Assemble the primary JPEG image, the gain map and the metadata to JPEG/R format.
+     * Assemble the primary JPEG image, the gain map and the metadata to JPEG/R format. Adds an ICC
+     * profile if one isn't present in the input JPEG image.
      * @param compressed_jpeg_image compressed 8-bit JPEG image
      * @param compressed_gainmap compressed 8-bit JPEG single channel image
      * @param metadata metadata to be written in XMP of the primary jpeg
@@ -217,6 +221,9 @@
      * Decode API
      * Decompress JPEGR image.
      *
+     * This method assumes that the JPEGR image contains an ICC profile with primaries that match
+     * those of a color gamut that this library is aware of; Bt.709, Display-P3, or Bt.2100.
+     *
      * @param compressed_jpegr_image compressed JPEGR image.
      * @param dest destination of the uncompressed JPEGR image.
      * @param max_display_boost (optional) the maximum available boost supported by a display,
@@ -270,26 +277,30 @@
     /*
      * This method is called in the encoding pipeline. It will take the uncompressed 8-bit and
      * 10-bit yuv images as input, and calculate the uncompressed gain map. The input images
-     * must be the same resolution.
+     * must be the same resolution. The SDR input is assumed to use the sRGB transfer function.
      *
      * @param uncompressed_yuv_420_image uncompressed SDR image in YUV_420 color format
      * @param uncompressed_p010_image uncompressed HDR image in P010 color format
      * @param hdr_tf transfer function of the HDR image
      * @param dest gain map; caller responsible for memory of data
      * @param metadata max_content_boost is filled in
+     * @param sdr_is_601 if true, then use BT.601 decoding of YUV regardless of SDR image gamut
      * @return NO_ERROR if calculation succeeds, error code if error occurs.
      */
     status_t generateGainMap(jr_uncompressed_ptr uncompressed_yuv_420_image,
                              jr_uncompressed_ptr uncompressed_p010_image,
                              ultrahdr_transfer_function hdr_tf,
                              ultrahdr_metadata_ptr metadata,
-                             jr_uncompressed_ptr dest);
+                             jr_uncompressed_ptr dest,
+                             bool sdr_is_601 = false);
 
     /*
      * This method is called in the decoding pipeline. It will take the uncompressed (decoded)
      * 8-bit yuv image, the uncompressed (decoded) gain map, and extracted JPEG/R metadata as
      * input, and calculate the 10-bit recovered image. The recovered output image is the same
      * color gamut as the SDR image, with HLG transfer function, and is in RGBA1010102 data format.
+     * The SDR image is assumed to use the sRGB transfer function. The SDR image is also assumed to
+     * be a decoded JPEG for the purpose of YUV interpration.
      *
      * @param uncompressed_yuv_420_image uncompressed SDR image in YUV_420 color format
      * @param uncompressed_gain_map uncompressed gain map
@@ -353,6 +364,8 @@
      * @param compressed_jpeg_image compressed 8-bit JPEG image
      * @param compress_gain_map compressed recover map
      * @param (nullable) exif EXIF package
+     * @param (nullable) icc ICC package
+     * @param icc_size length in bytes of ICC package
      * @param metadata JPEG/R metadata to encode in XMP of the jpeg
      * @param dest compressed JPEGR image
      * @return NO_ERROR if calculation succeeds, error code if error occurs.
@@ -360,6 +373,7 @@
     status_t appendGainMap(jr_compressed_ptr compressed_jpeg_image,
                            jr_compressed_ptr compressed_gain_map,
                            jr_exif_ptr exif,
+                           void* icc, size_t icc_size,
                            ultrahdr_metadata_ptr metadata,
                            jr_compressed_ptr dest);
 
@@ -374,6 +388,22 @@
                      jr_uncompressed_ptr dest);
 
     /*
+     * This method will convert a YUV420 image from one YUV encoding to another in-place (eg.
+     * Bt.709 to Bt.601 YUV encoding).
+     *
+     * src_encoding and dest_encoding indicate the encoding via the YUV conversion defined for that
+     * gamut. P3 indicates Rec.601, since this is how DataSpace encodes Display-P3 YUV data.
+     *
+     * @param image the YUV420 image to convert
+     * @param src_encoding input YUV encoding
+     * @param dest_encoding output YUV encoding
+     * @return NO_ERROR if calculation succeeds, error code if error occurs.
+     */
+    status_t convertYuv(jr_uncompressed_ptr image,
+                        ultrahdr_color_gamut src_encoding,
+                        ultrahdr_color_gamut dest_encoding);
+
+    /*
      * This method will check the validity of the input arguments.
      *
      * @param uncompressed_p010_image uncompressed HDR image in P010 color format
diff --git a/libs/ultrahdr/jpegdecoderhelper.cpp b/libs/ultrahdr/jpegdecoderhelper.cpp
index 0bad4a4..fef5444 100644
--- a/libs/ultrahdr/jpegdecoderhelper.cpp
+++ b/libs/ultrahdr/jpegdecoderhelper.cpp
@@ -93,7 +93,6 @@
 }
 
 JpegDecoderHelper::JpegDecoderHelper() {
-  mExifPos = 0;
 }
 
 JpegDecoderHelper::~JpegDecoderHelper() {
@@ -138,6 +137,14 @@
     return mEXIFBuffer.size();
 }
 
+void* JpegDecoderHelper::getICCPtr() {
+    return mICCBuffer.data();
+}
+
+size_t JpegDecoderHelper::getICCSize() {
+    return mICCBuffer.size();
+}
+
 size_t JpegDecoderHelper::getDecompressedImageWidth() {
     return mWidth;
 }
@@ -168,31 +175,21 @@
     cinfo.src = &mgr;
     jpeg_read_header(&cinfo, TRUE);
 
-    // Save XMP data and EXIF data.
-    // Here we only handle the first XMP / EXIF package.
-    // The parameter pos is used for capturing start offset of EXIF, which is hacky, but working...
+    // Save XMP data, EXIF data, and ICC data.
+    // Here we only handle the first XMP / EXIF / ICC package.
     // We assume that all packages are starting with two bytes marker (eg FF E1 for EXIF package),
     // two bytes of package length which is stored in marker->original_length, and the real data
-    // which is stored in marker->data. The pos is adding up all previous package lengths (
-    // 4 bytes marker and length, marker->original_length) before EXIF appears. Note that here we
-    // we are using marker->original_length instead of marker->data_length because in case the real
-    // package length is larger than the limitation, jpeg-turbo will only copy the data within the
-    // limitation (represented by data_length) and this may vary from original_length / real offset.
-    // A better solution is making jpeg_marker_struct holding the offset, but currently it doesn't.
+    // which is stored in marker->data.
     bool exifAppears = false;
     bool xmpAppears = false;
-    size_t pos = 2;  // position after SOI
+    bool iccAppears = false;
     for (jpeg_marker_struct* marker = cinfo.marker_list;
-         marker && !(exifAppears && xmpAppears);
+         marker && !(exifAppears && xmpAppears && iccAppears);
          marker = marker->next) {
 
-        pos += 4;
-        pos += marker->original_length;
-
-        if (marker->marker != kAPP1Marker) {
+        if (marker->marker != kAPP1Marker && marker->marker != kAPP2Marker) {
             continue;
         }
-
         const unsigned int len = marker->data_length;
         if (!xmpAppears &&
             len > kXmpNameSpace.size() &&
@@ -210,7 +207,12 @@
             mEXIFBuffer.resize(len, 0);
             memcpy(static_cast<void*>(mEXIFBuffer.data()), marker->data, len);
             exifAppears = true;
-            mExifPos = pos - marker->original_length;
+        } else if (!iccAppears &&
+                   len > sizeof(kICCSig) &&
+                   !memcmp(marker->data, kICCSig, sizeof(kICCSig))) {
+            mICCBuffer.resize(len, 0);
+            memcpy(static_cast<void*>(mICCBuffer.data()), marker->data, len);
+            iccAppears = true;
         }
     }
 
@@ -228,6 +230,7 @@
         if (cinfo.jpeg_color_space == JCS_GRAYSCALE) {
             // We don't intend to support decoding grayscale to RGBA
             status = false;
+            ALOGE("%s: decoding grayscale to RGBA is unsupported", __func__);
             goto CleanUp;
         }
         // 4 bytes per pixel
@@ -242,6 +245,7 @@
                 cinfo.comp_info[1].v_samp_factor != 1 ||
                 cinfo.comp_info[2].v_samp_factor != 1) {
                 status = false;
+                ALOGE("%s: decoding to YUV only supports 4:2:0 subsampling", __func__);
                 goto CleanUp;
             }
             mResultBuffer.resize(cinfo.image_width * cinfo.image_height * 3 / 2, 0);
@@ -304,8 +308,12 @@
         return false;
     }
 
-    *pWidth = cinfo.image_width;
-    *pHeight = cinfo.image_height;
+    if (pWidth != nullptr) {
+        *pWidth = cinfo.image_width;
+    }
+    if (pHeight != nullptr) {
+        *pHeight = cinfo.image_height;
+    }
 
     if (iccData != nullptr) {
         for (jpeg_marker_struct* marker = cinfo.marker_list; marker;
@@ -318,9 +326,7 @@
                 continue;
             }
 
-            const unsigned int len = marker->data_length - kICCMarkerHeaderSize;
-            const uint8_t *src = marker->data + kICCMarkerHeaderSize;
-            iccData->insert(iccData->end(), src, src+len);
+            iccData->insert(iccData->end(), marker->data, marker->data + marker->data_length);
         }
     }
 
diff --git a/libs/ultrahdr/jpegr.cpp b/libs/ultrahdr/jpegr.cpp
index 415255d..9af5af7 100644
--- a/libs/ultrahdr/jpegr.cpp
+++ b/libs/ultrahdr/jpegr.cpp
@@ -258,6 +258,10 @@
   sp<DataStruct> icc = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB,
                                                   uncompressed_yuv_420_image.colorGamut);
 
+  // Convert to Bt601 YUV encoding for JPEG encode
+  JPEGR_CHECK(convertYuv(&uncompressed_yuv_420_image, uncompressed_yuv_420_image.colorGamut,
+                         ULTRAHDR_COLORGAMUT_P3));
+
   JpegEncoderHelper jpeg_encoder;
   if (!jpeg_encoder.compressImage(uncompressed_yuv_420_image.data,
                                   uncompressed_yuv_420_image.width,
@@ -269,7 +273,9 @@
   jpeg.data = jpeg_encoder.getCompressedImagePtr();
   jpeg.length = jpeg_encoder.getCompressedImageSize();
 
-  JPEGR_CHECK(appendGainMap(&jpeg, &compressed_map, exif, &metadata, dest));
+  // No ICC since JPEG encode already did it
+  JPEGR_CHECK(appendGainMap(&jpeg, &compressed_map, exif, /* icc */ nullptr, /* icc size */ 0,
+                            &metadata, dest));
 
   return NO_ERROR;
 }
@@ -317,10 +323,22 @@
   sp<DataStruct> icc = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB,
                                                   uncompressed_yuv_420_image->colorGamut);
 
+  // Convert to Bt601 YUV encoding for JPEG encode; make a copy so as to no clobber client data
+  unique_ptr<uint8_t[]> yuv_420_bt601_data = make_unique<uint8_t[]>(
+      uncompressed_yuv_420_image->width * uncompressed_yuv_420_image->height * 3 / 2);
+  memcpy(yuv_420_bt601_data.get(), uncompressed_yuv_420_image->data,
+         uncompressed_yuv_420_image->width * uncompressed_yuv_420_image->height * 3 / 2);
+
+  jpegr_uncompressed_struct yuv_420_bt601_image = {
+    yuv_420_bt601_data.get(), uncompressed_yuv_420_image->width, uncompressed_yuv_420_image->height,
+    uncompressed_yuv_420_image->colorGamut };
+  JPEGR_CHECK(convertYuv(&yuv_420_bt601_image, yuv_420_bt601_image.colorGamut,
+                         ULTRAHDR_COLORGAMUT_P3));
+
   JpegEncoderHelper jpeg_encoder;
-  if (!jpeg_encoder.compressImage(uncompressed_yuv_420_image->data,
-                                  uncompressed_yuv_420_image->width,
-                                  uncompressed_yuv_420_image->height, quality,
+  if (!jpeg_encoder.compressImage(yuv_420_bt601_image.data,
+                                  yuv_420_bt601_image.width,
+                                  yuv_420_bt601_image.height, quality,
                                   icc->getData(), icc->getLength())) {
     return ERROR_JPEGR_ENCODE_ERROR;
   }
@@ -328,7 +346,9 @@
   jpeg.data = jpeg_encoder.getCompressedImagePtr();
   jpeg.length = jpeg_encoder.getCompressedImageSize();
 
-  JPEGR_CHECK(appendGainMap(&jpeg, &compressed_map, exif, &metadata, dest));
+  // No ICC since jpeg encode already did it
+  JPEGR_CHECK(appendGainMap(&jpeg, &compressed_map, exif, /* icc */ nullptr, /* icc size */ 0,
+                            &metadata, dest));
 
   return NO_ERROR;
 }
@@ -371,7 +391,24 @@
   compressed_map.data = jpeg_encoder_gainmap.getCompressedImagePtr();
   compressed_map.colorGamut = ULTRAHDR_COLORGAMUT_UNSPECIFIED;
 
-  JPEGR_CHECK(appendGainMap(compressed_jpeg_image, &compressed_map, nullptr, &metadata, dest));
+  // We just want to check if ICC is present, so don't do a full decode. Note,
+  // this doesn't verify that the ICC is valid.
+  JpegDecoderHelper decoder;
+  std::vector<uint8_t> icc;
+  decoder.getCompressedImageParameters(compressed_jpeg_image->data, compressed_jpeg_image->length,
+                                       /* pWidth */ nullptr, /* pHeight */ nullptr,
+                                       &icc, /* exifData */ nullptr);
+
+  // Add ICC if not already present.
+  if (icc.size() > 0) {
+      JPEGR_CHECK(appendGainMap(compressed_jpeg_image, &compressed_map, /* exif */ nullptr,
+                                /* icc */ nullptr, /* icc size */ 0, &metadata, dest));
+  } else {
+      sp<DataStruct> newIcc = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB,
+                                                         uncompressed_yuv_420_image->colorGamut);
+      JPEGR_CHECK(appendGainMap(compressed_jpeg_image, &compressed_map, /* exif */ nullptr,
+                                newIcc->getData(), newIcc->getLength(), &metadata, dest));
+  }
 
   return NO_ERROR;
 }
@@ -392,6 +429,7 @@
     return ret;
   }
 
+  // Note: output is Bt.601 YUV encoded regardless of gamut, due to jpeg decode.
   JpegDecoderHelper jpeg_decoder;
   if (!jpeg_decoder.decompressImage(compressed_jpeg_image->data, compressed_jpeg_image->length)) {
     return ERROR_JPEGR_DECODE_ERROR;
@@ -411,8 +449,10 @@
   metadata.version = kJpegrVersion;
 
   jpegr_uncompressed_struct map;
+  // Indicate that the SDR image is Bt.601 YUV encoded.
   JPEGR_CHECK(generateGainMap(
-      &uncompressed_yuv_420_image, uncompressed_p010_image, hdr_tf, &metadata, &map));
+      &uncompressed_yuv_420_image, uncompressed_p010_image, hdr_tf, &metadata, &map,
+      true /* sdr_is_601 */ ));
   std::unique_ptr<uint8_t[]> map_data;
   map_data.reset(reinterpret_cast<uint8_t*>(map.data));
 
@@ -424,7 +464,24 @@
   compressed_map.data = jpeg_encoder_gainmap.getCompressedImagePtr();
   compressed_map.colorGamut = ULTRAHDR_COLORGAMUT_UNSPECIFIED;
 
-  JPEGR_CHECK(appendGainMap(compressed_jpeg_image, &compressed_map, nullptr, &metadata, dest));
+  // We just want to check if ICC is present, so don't do a full decode. Note,
+  // this doesn't verify that the ICC is valid.
+  JpegDecoderHelper decoder;
+  std::vector<uint8_t> icc;
+  decoder.getCompressedImageParameters(compressed_jpeg_image->data, compressed_jpeg_image->length,
+                                       /* pWidth */ nullptr, /* pHeight */ nullptr,
+                                       &icc, /* exifData */ nullptr);
+
+  // Add ICC if not already present.
+  if (icc.size() > 0) {
+      JPEGR_CHECK(appendGainMap(compressed_jpeg_image, &compressed_map, /* exif */ nullptr,
+                                /* icc */ nullptr, /* icc size */ 0, &metadata, dest));
+  } else {
+      sp<DataStruct> newIcc = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB,
+                                                         uncompressed_yuv_420_image.colorGamut);
+      JPEGR_CHECK(appendGainMap(compressed_jpeg_image, &compressed_map, /* exif */ nullptr,
+                                newIcc->getData(), newIcc->getLength(), &metadata, dest));
+  }
 
   return NO_ERROR;
 }
@@ -449,8 +506,25 @@
     return ERROR_JPEGR_INVALID_NULL_PTR;
   }
 
-  JPEGR_CHECK(appendGainMap(compressed_jpeg_image, compressed_gainmap, /* exif */ nullptr,
-          metadata, dest));
+  // We just want to check if ICC is present, so don't do a full decode. Note,
+  // this doesn't verify that the ICC is valid.
+  JpegDecoderHelper decoder;
+  std::vector<uint8_t> icc;
+  decoder.getCompressedImageParameters(compressed_jpeg_image->data, compressed_jpeg_image->length,
+                                       /* pWidth */ nullptr, /* pHeight */ nullptr,
+                                       &icc, /* exifData */ nullptr);
+
+  // Add ICC if not already present.
+  if (icc.size() > 0) {
+      JPEGR_CHECK(appendGainMap(compressed_jpeg_image, compressed_gainmap, /* exif */ nullptr,
+                                /* icc */ nullptr, /* icc size */ 0, metadata, dest));
+  } else {
+      sp<DataStruct> newIcc = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB,
+                                                         compressed_jpeg_image->colorGamut);
+      JPEGR_CHECK(appendGainMap(compressed_jpeg_image, compressed_gainmap, /* exif */ nullptr,
+                                newIcc->getData(), newIcc->getLength(), metadata, dest));
+  }
+
   return NO_ERROR;
 }
 
@@ -613,6 +687,9 @@
   uncompressed_yuv_420_image.data = jpeg_decoder.getDecompressedImagePtr();
   uncompressed_yuv_420_image.width = jpeg_decoder.getDecompressedImageWidth();
   uncompressed_yuv_420_image.height = jpeg_decoder.getDecompressedImageHeight();
+  uncompressed_yuv_420_image.colorGamut = IccHelper::readIccColorGamut(
+      jpeg_decoder.getICCPtr(), jpeg_decoder.getICCSize());
+
   JPEGR_CHECK(applyGainMap(&uncompressed_yuv_420_image, &map, &uhdr_metadata, output_format,
                            max_display_boost, dest));
   return NO_ERROR;
@@ -624,6 +701,7 @@
     return ERROR_JPEGR_INVALID_NULL_PTR;
   }
 
+  // Don't need to convert YUV to Bt601 since single channel
   if (!jpeg_encoder->compressImage(uncompressed_gain_map->data,
                                    uncompressed_gain_map->width,
                                    uncompressed_gain_map->height,
@@ -699,7 +777,8 @@
                                 jr_uncompressed_ptr uncompressed_p010_image,
                                 ultrahdr_transfer_function hdr_tf,
                                 ultrahdr_metadata_ptr metadata,
-                                jr_uncompressed_ptr dest) {
+                                jr_uncompressed_ptr dest,
+                                bool sdr_is_601) {
   if (uncompressed_yuv_420_image == nullptr
    || uncompressed_p010_image == nullptr
    || metadata == nullptr
@@ -768,15 +847,38 @@
       uncompressed_yuv_420_image->colorGamut, uncompressed_p010_image->colorGamut);
 
   ColorCalculationFn luminanceFn = nullptr;
+  ColorTransformFn sdrYuvToRgbFn = nullptr;
   switch (uncompressed_yuv_420_image->colorGamut) {
     case ULTRAHDR_COLORGAMUT_BT709:
       luminanceFn = srgbLuminance;
+      sdrYuvToRgbFn = srgbYuvToRgb;
       break;
     case ULTRAHDR_COLORGAMUT_P3:
       luminanceFn = p3Luminance;
+      sdrYuvToRgbFn = p3YuvToRgb;
       break;
     case ULTRAHDR_COLORGAMUT_BT2100:
       luminanceFn = bt2100Luminance;
+      sdrYuvToRgbFn = bt2100YuvToRgb;
+      break;
+    case ULTRAHDR_COLORGAMUT_UNSPECIFIED:
+      // Should be impossible to hit after input validation.
+      return ERROR_JPEGR_INVALID_COLORGAMUT;
+  }
+  if (sdr_is_601) {
+    sdrYuvToRgbFn = p3YuvToRgb;
+  }
+
+  ColorTransformFn hdrYuvToRgbFn = nullptr;
+  switch (uncompressed_p010_image->colorGamut) {
+    case ULTRAHDR_COLORGAMUT_BT709:
+      hdrYuvToRgbFn = srgbYuvToRgb;
+      break;
+    case ULTRAHDR_COLORGAMUT_P3:
+      hdrYuvToRgbFn = p3YuvToRgb;
+      break;
+    case ULTRAHDR_COLORGAMUT_BT2100:
+      hdrYuvToRgbFn = bt2100YuvToRgb;
       break;
     case ULTRAHDR_COLORGAMUT_UNSPECIFIED:
       // Should be impossible to hit after input validation.
@@ -790,8 +892,8 @@
 
   std::function<void()> generateMap = [uncompressed_yuv_420_image, uncompressed_p010_image,
                                        metadata, dest, hdrInvOetf, hdrGamutConversionFn,
-                                       luminanceFn, hdr_white_nits, log2MinBoost, log2MaxBoost,
-                                       &jobQueue]() -> void {
+                                       luminanceFn, sdrYuvToRgbFn, hdrYuvToRgbFn, hdr_white_nits,
+                                       log2MinBoost, log2MaxBoost, &jobQueue]() -> void {
     size_t rowStart, rowEnd;
     size_t dest_map_width = uncompressed_yuv_420_image->width / kMapDimensionScaleFactor;
     size_t dest_map_stride = dest->width;
@@ -800,7 +902,8 @@
         for (size_t x = 0; x < dest_map_width; ++x) {
           Color sdr_yuv_gamma =
               sampleYuv420(uncompressed_yuv_420_image, kMapDimensionScaleFactor, x, y);
-          Color sdr_rgb_gamma = srgbYuvToRgb(sdr_yuv_gamma);
+          Color sdr_rgb_gamma = sdrYuvToRgbFn(sdr_yuv_gamma);
+          // We are assuming the SDR input is always sRGB transfer.
 #if USE_SRGB_INVOETF_LUT
           Color sdr_rgb = srgbInvOetfLUT(sdr_rgb_gamma);
 #else
@@ -809,7 +912,7 @@
           float sdr_y_nits = luminanceFn(sdr_rgb) * kSdrWhiteNits;
 
           Color hdr_yuv_gamma = sampleP010(uncompressed_p010_image, kMapDimensionScaleFactor, x, y);
-          Color hdr_rgb_gamma = bt2100YuvToRgb(hdr_yuv_gamma);
+          Color hdr_rgb_gamma = hdrYuvToRgbFn(hdr_yuv_gamma);
           Color hdr_rgb = hdrInvOetf(hdr_rgb_gamma);
           hdr_rgb = hdrGamutConversionFn(hdr_rgb);
           float hdr_y_nits = luminanceFn(hdr_rgb) * hdr_white_nits;
@@ -887,7 +990,9 @@
       for (size_t y = rowStart; y < rowEnd; ++y) {
         for (size_t x = 0; x < width; ++x) {
           Color yuv_gamma_sdr = getYuv420Pixel(uncompressed_yuv_420_image, x, y);
-          Color rgb_gamma_sdr = srgbYuvToRgb(yuv_gamma_sdr);
+          // Assuming the sdr image is a decoded JPEG, we should always use Rec.601 YUV coefficients
+          Color rgb_gamma_sdr = p3YuvToRgb(yuv_gamma_sdr);
+          // We are assuming the SDR base image is always sRGB transfer.
 #if USE_SRGB_INVOETF_LUT
           Color rgb_sdr = srgbInvOetfLUT(rgb_gamma_sdr);
 #else
@@ -1065,6 +1170,7 @@
 status_t JpegR::appendGainMap(jr_compressed_ptr compressed_jpeg_image,
                               jr_compressed_ptr compressed_gain_map,
                               jr_exif_ptr exif,
+                              void* icc, size_t icc_size,
                               ultrahdr_metadata_ptr metadata,
                               jr_compressed_ptr dest) {
   if (compressed_jpeg_image == nullptr
@@ -1128,6 +1234,18 @@
     JPEGR_CHECK(Write(dest, (void*)xmp_primary.c_str(), xmp_primary.size(), pos));
   }
 
+  // Write ICC
+  if (icc != nullptr && icc_size > 0) {
+      const int length = icc_size + 2;
+      const uint8_t lengthH = ((length >> 8) & 0xff);
+      const uint8_t lengthL = (length & 0xff);
+      JPEGR_CHECK(Write(dest, &photos_editing_formats::image_io::JpegMarker::kStart, 1, pos));
+      JPEGR_CHECK(Write(dest, &photos_editing_formats::image_io::JpegMarker::kAPP2, 1, pos));
+      JPEGR_CHECK(Write(dest, &lengthH, 1, pos));
+      JPEGR_CHECK(Write(dest, &lengthL, 1, pos));
+      JPEGR_CHECK(Write(dest, icc, icc_size, pos));
+  }
+
   // Prepare and write MPF
   {
       const int length = 2 + calculateMpfSize();
@@ -1235,4 +1353,82 @@
   return NO_ERROR;
 }
 
+status_t JpegR::convertYuv(jr_uncompressed_ptr image,
+                           ultrahdr_color_gamut src_encoding,
+                           ultrahdr_color_gamut dest_encoding) {
+  if (image == nullptr) {
+    return ERROR_JPEGR_INVALID_NULL_PTR;
+  }
+
+  if (src_encoding == ULTRAHDR_COLORGAMUT_UNSPECIFIED
+   || dest_encoding == ULTRAHDR_COLORGAMUT_UNSPECIFIED) {
+    return ERROR_JPEGR_INVALID_COLORGAMUT;
+  }
+
+  ColorTransformFn conversionFn = nullptr;
+  switch (src_encoding) {
+    case ULTRAHDR_COLORGAMUT_BT709:
+      switch (dest_encoding) {
+        case ULTRAHDR_COLORGAMUT_BT709:
+          return NO_ERROR;
+        case ULTRAHDR_COLORGAMUT_P3:
+          conversionFn = yuv709To601;
+          break;
+        case ULTRAHDR_COLORGAMUT_BT2100:
+          conversionFn = yuv709To2100;
+          break;
+        default:
+          // Should be impossible to hit after input validation
+          return ERROR_JPEGR_INVALID_COLORGAMUT;
+      }
+      break;
+    case ULTRAHDR_COLORGAMUT_P3:
+      switch (dest_encoding) {
+        case ULTRAHDR_COLORGAMUT_BT709:
+          conversionFn = yuv601To709;
+          break;
+        case ULTRAHDR_COLORGAMUT_P3:
+          return NO_ERROR;
+        case ULTRAHDR_COLORGAMUT_BT2100:
+          conversionFn = yuv601To2100;
+          break;
+        default:
+          // Should be impossible to hit after input validation
+          return ERROR_JPEGR_INVALID_COLORGAMUT;
+      }
+      break;
+    case ULTRAHDR_COLORGAMUT_BT2100:
+      switch (dest_encoding) {
+        case ULTRAHDR_COLORGAMUT_BT709:
+          conversionFn = yuv2100To709;
+          break;
+        case ULTRAHDR_COLORGAMUT_P3:
+          conversionFn = yuv2100To601;
+          break;
+        case ULTRAHDR_COLORGAMUT_BT2100:
+          return NO_ERROR;
+        default:
+          // Should be impossible to hit after input validation
+          return ERROR_JPEGR_INVALID_COLORGAMUT;
+      }
+      break;
+    default:
+      // Should be impossible to hit after input validation
+      return ERROR_JPEGR_INVALID_COLORGAMUT;
+  }
+
+  if (conversionFn == nullptr) {
+    // Should be impossible to hit after input validation
+    return ERROR_JPEGR_INVALID_COLORGAMUT;
+  }
+
+  for (size_t y = 0; y < image->height / 2; ++y) {
+    for (size_t x = 0; x < image->width / 2; ++x) {
+      transformYuv420(image, x, y, conversionFn);
+    }
+  }
+
+  return NO_ERROR;
+}
+
 } // namespace android::ultrahdr
diff --git a/libs/ultrahdr/tests/Android.bp b/libs/ultrahdr/tests/Android.bp
index 7dd9d04..5944130 100644
--- a/libs/ultrahdr/tests/Android.bp
+++ b/libs/ultrahdr/tests/Android.bp
@@ -25,8 +25,9 @@
     name: "libultrahdr_test",
     test_suites: ["device-tests"],
     srcs: [
-        "jpegr_test.cpp",
         "gainmapmath_test.cpp",
+        "icchelper_test.cpp",
+        "jpegr_test.cpp",
     ],
     shared_libs: [
         "libimage_io",
@@ -72,5 +73,7 @@
     static_libs: [
         "libgtest",
         "libjpegdecoder",
+        "libultrahdr",
+        "libutils",
     ],
 }
diff --git a/libs/ultrahdr/tests/data/minnie-320x240-yuv-icc.jpg b/libs/ultrahdr/tests/data/minnie-320x240-yuv-icc.jpg
new file mode 100644
index 0000000..f61e0e8
--- /dev/null
+++ b/libs/ultrahdr/tests/data/minnie-320x240-yuv-icc.jpg
Binary files differ
diff --git a/libs/ultrahdr/tests/gainmapmath_test.cpp b/libs/ultrahdr/tests/gainmapmath_test.cpp
index c456653..af90365 100644
--- a/libs/ultrahdr/tests/gainmapmath_test.cpp
+++ b/libs/ultrahdr/tests/gainmapmath_test.cpp
@@ -28,6 +28,7 @@
 
   float ComparisonEpsilon() { return 1e-4f; }
   float LuminanceEpsilon() { return 1e-2f; }
+  float YuvConversionEpsilon() { return 1.0f / (255.0f * 2.0f); }
 
   Color Yuv420(uint8_t y, uint8_t u, uint8_t v) {
       return {{{ static_cast<float>(y) / 255.0f,
@@ -63,9 +64,13 @@
   Color YuvBlack() { return {{{ 0.0f, 0.0f, 0.0f }}}; }
   Color YuvWhite() { return {{{ 1.0f, 0.0f, 0.0f }}}; }
 
-  Color SrgbYuvRed() { return {{{ 0.299f, -0.1687f, 0.5f }}}; }
-  Color SrgbYuvGreen() { return {{{ 0.587f, -0.3313f, -0.4187f }}}; }
-  Color SrgbYuvBlue() { return {{{ 0.114f, 0.5f, -0.0813f }}}; }
+  Color SrgbYuvRed() { return {{{ 0.2126f, -0.11457f, 0.5f }}}; }
+  Color SrgbYuvGreen() { return {{{ 0.7152f, -0.38543f, -0.45415f }}}; }
+  Color SrgbYuvBlue() { return {{{ 0.0722f, 0.5f, -0.04585f }}}; }
+
+  Color P3YuvRed() { return {{{ 0.299f, -0.16874f, 0.5f }}}; }
+  Color P3YuvGreen() { return {{{ 0.587f, -0.33126f, -0.41869f }}}; }
+  Color P3YuvBlue() { return {{{ 0.114f, 0.5f, -0.08131f }}}; }
 
   Color Bt2100YuvRed() { return {{{ 0.2627f, -0.13963f, 0.5f }}}; }
   Color Bt2100YuvGreen() { return {{{ 0.6780f, -0.36037f, -0.45979f }}}; }
@@ -78,6 +83,13 @@
     return luminance_scaled * kSdrWhiteNits;
   }
 
+  float P3YuvToLuminance(Color yuv_gamma, ColorCalculationFn luminanceFn) {
+    Color rgb_gamma = p3YuvToRgb(yuv_gamma);
+    Color rgb = srgbInvOetf(rgb_gamma);
+    float luminance_scaled = luminanceFn(rgb);
+    return luminance_scaled * kSdrWhiteNits;
+  }
+
   float Bt2100YuvToLuminance(Color yuv_gamma, ColorTransformFn hdrInvOetf,
                              ColorTransformFn gamutConversionFn, ColorCalculationFn luminanceFn,
                              float scale_factor) {
@@ -402,6 +414,56 @@
   EXPECT_FLOAT_EQ(p3Luminance(RgbBlue()), 0.06891f);
 }
 
+TEST_F(GainMapMathTest, P3YuvToRgb) {
+  Color rgb_black = p3YuvToRgb(YuvBlack());
+  EXPECT_RGB_NEAR(rgb_black, RgbBlack());
+
+  Color rgb_white = p3YuvToRgb(YuvWhite());
+  EXPECT_RGB_NEAR(rgb_white, RgbWhite());
+
+  Color rgb_r = p3YuvToRgb(P3YuvRed());
+  EXPECT_RGB_NEAR(rgb_r, RgbRed());
+
+  Color rgb_g = p3YuvToRgb(P3YuvGreen());
+  EXPECT_RGB_NEAR(rgb_g, RgbGreen());
+
+  Color rgb_b = p3YuvToRgb(P3YuvBlue());
+  EXPECT_RGB_NEAR(rgb_b, RgbBlue());
+}
+
+TEST_F(GainMapMathTest, P3RgbToYuv) {
+  Color yuv_black = p3RgbToYuv(RgbBlack());
+  EXPECT_YUV_NEAR(yuv_black, YuvBlack());
+
+  Color yuv_white = p3RgbToYuv(RgbWhite());
+  EXPECT_YUV_NEAR(yuv_white, YuvWhite());
+
+  Color yuv_r = p3RgbToYuv(RgbRed());
+  EXPECT_YUV_NEAR(yuv_r, P3YuvRed());
+
+  Color yuv_g = p3RgbToYuv(RgbGreen());
+  EXPECT_YUV_NEAR(yuv_g, P3YuvGreen());
+
+  Color yuv_b = p3RgbToYuv(RgbBlue());
+  EXPECT_YUV_NEAR(yuv_b, P3YuvBlue());
+}
+
+TEST_F(GainMapMathTest, P3RgbYuvRoundtrip) {
+  Color rgb_black = p3YuvToRgb(p3RgbToYuv(RgbBlack()));
+  EXPECT_RGB_NEAR(rgb_black, RgbBlack());
+
+  Color rgb_white = p3YuvToRgb(p3RgbToYuv(RgbWhite()));
+  EXPECT_RGB_NEAR(rgb_white, RgbWhite());
+
+  Color rgb_r = p3YuvToRgb(p3RgbToYuv(RgbRed()));
+  EXPECT_RGB_NEAR(rgb_r, RgbRed());
+
+  Color rgb_g = p3YuvToRgb(p3RgbToYuv(RgbGreen()));
+  EXPECT_RGB_NEAR(rgb_g, RgbGreen());
+
+  Color rgb_b = p3YuvToRgb(p3RgbToYuv(RgbBlue()));
+  EXPECT_RGB_NEAR(rgb_b, RgbBlue());
+}
 TEST_F(GainMapMathTest, Bt2100Luminance) {
   EXPECT_FLOAT_EQ(bt2100Luminance(RgbBlack()), 0.0f);
   EXPECT_FLOAT_EQ(bt2100Luminance(RgbWhite()), 1.0f);
@@ -461,6 +523,163 @@
   EXPECT_RGB_NEAR(rgb_b, RgbBlue());
 }
 
+TEST_F(GainMapMathTest, Bt709ToBt601YuvConversion) {
+  Color yuv_black = srgbRgbToYuv(RgbBlack());
+  EXPECT_YUV_NEAR(yuv709To601(yuv_black), YuvBlack());
+
+  Color yuv_white = srgbRgbToYuv(RgbWhite());
+  EXPECT_YUV_NEAR(yuv709To601(yuv_white), YuvWhite());
+
+  Color yuv_r = srgbRgbToYuv(RgbRed());
+  EXPECT_YUV_NEAR(yuv709To601(yuv_r), P3YuvRed());
+
+  Color yuv_g = srgbRgbToYuv(RgbGreen());
+  EXPECT_YUV_NEAR(yuv709To601(yuv_g), P3YuvGreen());
+
+  Color yuv_b = srgbRgbToYuv(RgbBlue());
+  EXPECT_YUV_NEAR(yuv709To601(yuv_b), P3YuvBlue());
+}
+
+TEST_F(GainMapMathTest, Bt709ToBt2100YuvConversion) {
+  Color yuv_black = srgbRgbToYuv(RgbBlack());
+  EXPECT_YUV_NEAR(yuv709To2100(yuv_black), YuvBlack());
+
+  Color yuv_white = srgbRgbToYuv(RgbWhite());
+  EXPECT_YUV_NEAR(yuv709To2100(yuv_white), YuvWhite());
+
+  Color yuv_r = srgbRgbToYuv(RgbRed());
+  EXPECT_YUV_NEAR(yuv709To2100(yuv_r), Bt2100YuvRed());
+
+  Color yuv_g = srgbRgbToYuv(RgbGreen());
+  EXPECT_YUV_NEAR(yuv709To2100(yuv_g), Bt2100YuvGreen());
+
+  Color yuv_b = srgbRgbToYuv(RgbBlue());
+  EXPECT_YUV_NEAR(yuv709To2100(yuv_b), Bt2100YuvBlue());
+}
+
+TEST_F(GainMapMathTest, Bt601ToBt709YuvConversion) {
+  Color yuv_black = p3RgbToYuv(RgbBlack());
+  EXPECT_YUV_NEAR(yuv601To709(yuv_black), YuvBlack());
+
+  Color yuv_white = p3RgbToYuv(RgbWhite());
+  EXPECT_YUV_NEAR(yuv601To709(yuv_white), YuvWhite());
+
+  Color yuv_r = p3RgbToYuv(RgbRed());
+  EXPECT_YUV_NEAR(yuv601To709(yuv_r), SrgbYuvRed());
+
+  Color yuv_g = p3RgbToYuv(RgbGreen());
+  EXPECT_YUV_NEAR(yuv601To709(yuv_g), SrgbYuvGreen());
+
+  Color yuv_b = p3RgbToYuv(RgbBlue());
+  EXPECT_YUV_NEAR(yuv601To709(yuv_b), SrgbYuvBlue());
+}
+
+TEST_F(GainMapMathTest, Bt601ToBt2100YuvConversion) {
+  Color yuv_black = p3RgbToYuv(RgbBlack());
+  EXPECT_YUV_NEAR(yuv601To2100(yuv_black), YuvBlack());
+
+  Color yuv_white = p3RgbToYuv(RgbWhite());
+  EXPECT_YUV_NEAR(yuv601To2100(yuv_white), YuvWhite());
+
+  Color yuv_r = p3RgbToYuv(RgbRed());
+  EXPECT_YUV_NEAR(yuv601To2100(yuv_r), Bt2100YuvRed());
+
+  Color yuv_g = p3RgbToYuv(RgbGreen());
+  EXPECT_YUV_NEAR(yuv601To2100(yuv_g), Bt2100YuvGreen());
+
+  Color yuv_b = p3RgbToYuv(RgbBlue());
+  EXPECT_YUV_NEAR(yuv601To2100(yuv_b), Bt2100YuvBlue());
+}
+
+TEST_F(GainMapMathTest, Bt2100ToBt709YuvConversion) {
+  Color yuv_black = bt2100RgbToYuv(RgbBlack());
+  EXPECT_YUV_NEAR(yuv2100To709(yuv_black), YuvBlack());
+
+  Color yuv_white = bt2100RgbToYuv(RgbWhite());
+  EXPECT_YUV_NEAR(yuv2100To709(yuv_white), YuvWhite());
+
+  Color yuv_r = bt2100RgbToYuv(RgbRed());
+  EXPECT_YUV_NEAR(yuv2100To709(yuv_r), SrgbYuvRed());
+
+  Color yuv_g = bt2100RgbToYuv(RgbGreen());
+  EXPECT_YUV_NEAR(yuv2100To709(yuv_g), SrgbYuvGreen());
+
+  Color yuv_b = bt2100RgbToYuv(RgbBlue());
+  EXPECT_YUV_NEAR(yuv2100To709(yuv_b), SrgbYuvBlue());
+}
+
+TEST_F(GainMapMathTest, Bt2100ToBt601YuvConversion) {
+  Color yuv_black = bt2100RgbToYuv(RgbBlack());
+  EXPECT_YUV_NEAR(yuv2100To601(yuv_black), YuvBlack());
+
+  Color yuv_white = bt2100RgbToYuv(RgbWhite());
+  EXPECT_YUV_NEAR(yuv2100To601(yuv_white), YuvWhite());
+
+  Color yuv_r = bt2100RgbToYuv(RgbRed());
+  EXPECT_YUV_NEAR(yuv2100To601(yuv_r), P3YuvRed());
+
+  Color yuv_g = bt2100RgbToYuv(RgbGreen());
+  EXPECT_YUV_NEAR(yuv2100To601(yuv_g), P3YuvGreen());
+
+  Color yuv_b = bt2100RgbToYuv(RgbBlue());
+  EXPECT_YUV_NEAR(yuv2100To601(yuv_b), P3YuvBlue());
+}
+
+TEST_F(GainMapMathTest, TransformYuv420) {
+  ColorTransformFn transforms[] = { yuv709To601, yuv709To2100, yuv601To709, yuv601To2100,
+                                    yuv2100To709, yuv2100To601 };
+  for (const ColorTransformFn& transform : transforms) {
+    jpegr_uncompressed_struct input = Yuv420Image();
+
+    size_t out_buf_size = input.width * input.height * 3 / 2;
+    std::unique_ptr<uint8_t[]> out_buf = std::make_unique<uint8_t[]>(out_buf_size);
+    memcpy(out_buf.get(), input.data, out_buf_size);
+    jpegr_uncompressed_struct output = Yuv420Image();
+    output.data = out_buf.get();
+
+    transformYuv420(&output, 1, 1, transform);
+
+    for (size_t y = 0; y < 4; ++y) {
+      for (size_t x = 0; x < 4; ++x) {
+        // Skip the last chroma sample, which we modified above
+        if (x >= 2 && y >= 2) {
+          continue;
+        }
+
+        // All other pixels should remain unchanged
+        EXPECT_YUV_EQ(getYuv420Pixel(&input, x, y), getYuv420Pixel(&output, x, y));
+      }
+    }
+
+    // modified pixels should be updated as intended by the transformYuv420 algorithm
+    Color in1 = getYuv420Pixel(&input,   2, 2);
+    Color in2 = getYuv420Pixel(&input,   3, 2);
+    Color in3 = getYuv420Pixel(&input,   2, 3);
+    Color in4 = getYuv420Pixel(&input,   3, 3);
+    Color out1 = getYuv420Pixel(&output, 2, 2);
+    Color out2 = getYuv420Pixel(&output, 3, 2);
+    Color out3 = getYuv420Pixel(&output, 2, 3);
+    Color out4 = getYuv420Pixel(&output, 3, 3);
+
+    EXPECT_NEAR(transform(in1).y, out1.y, YuvConversionEpsilon());
+    EXPECT_NEAR(transform(in2).y, out2.y, YuvConversionEpsilon());
+    EXPECT_NEAR(transform(in3).y, out3.y, YuvConversionEpsilon());
+    EXPECT_NEAR(transform(in4).y, out4.y, YuvConversionEpsilon());
+
+    Color expect_uv = (transform(in1) + transform(in2) + transform(in3) + transform(in4)) / 4.0f;
+
+    EXPECT_NEAR(expect_uv.u, out1.u, YuvConversionEpsilon());
+    EXPECT_NEAR(expect_uv.u, out2.u, YuvConversionEpsilon());
+    EXPECT_NEAR(expect_uv.u, out3.u, YuvConversionEpsilon());
+    EXPECT_NEAR(expect_uv.u, out4.u, YuvConversionEpsilon());
+
+    EXPECT_NEAR(expect_uv.v, out1.v, YuvConversionEpsilon());
+    EXPECT_NEAR(expect_uv.v, out2.v, YuvConversionEpsilon());
+    EXPECT_NEAR(expect_uv.v, out3.v, YuvConversionEpsilon());
+    EXPECT_NEAR(expect_uv.v, out4.v, YuvConversionEpsilon());
+  }
+}
+
 TEST_F(GainMapMathTest, HlgOetf) {
   EXPECT_FLOAT_EQ(hlgOetf(0.0f), 0.0f);
   EXPECT_NEAR(hlgOetf(0.04167f), 0.35357f, ComparisonEpsilon());
@@ -693,7 +912,7 @@
 
 TEST_F(GainMapMathTest, EncodeGain) {
   ultrahdr_metadata_struct metadata = { .maxContentBoost = 4.0f,
-                                     .minContentBoost = 1.0f / 4.0f };
+                                        .minContentBoost = 1.0f / 4.0f };
 
   EXPECT_EQ(encodeGain(0.0f, 0.0f, &metadata), 127);
   EXPECT_EQ(encodeGain(0.0f, 1.0f, &metadata), 127);
@@ -751,7 +970,7 @@
 
 TEST_F(GainMapMathTest, ApplyGain) {
   ultrahdr_metadata_struct metadata = { .maxContentBoost = 4.0f,
-                                     .minContentBoost = 1.0f / 4.0f };
+                                        .minContentBoost = 1.0f / 4.0f };
   float displayBoost = metadata.maxContentBoost;
 
   EXPECT_RGB_NEAR(applyGain(RgbBlack(), 0.0f, &metadata), RgbBlack());
diff --git a/libs/ultrahdr/tests/icchelper_test.cpp b/libs/ultrahdr/tests/icchelper_test.cpp
new file mode 100644
index 0000000..ff61c08
--- /dev/null
+++ b/libs/ultrahdr/tests/icchelper_test.cpp
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+#include <ultrahdr/icc.h>
+#include <ultrahdr/ultrahdr.h>
+#include <utils/Log.h>
+
+namespace android::ultrahdr {
+
+class IccHelperTest : public testing::Test {
+public:
+    IccHelperTest();
+    ~IccHelperTest();
+protected:
+    virtual void SetUp();
+    virtual void TearDown();
+};
+
+IccHelperTest::IccHelperTest() {}
+
+IccHelperTest::~IccHelperTest() {}
+
+void IccHelperTest::SetUp() {}
+
+void IccHelperTest::TearDown() {}
+
+TEST_F(IccHelperTest, iccWriteThenRead) {
+    sp<DataStruct> iccBt709 = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB,
+                                                         ULTRAHDR_COLORGAMUT_BT709);
+    ASSERT_NE(iccBt709->getLength(), 0);
+    ASSERT_NE(iccBt709->getData(), nullptr);
+    EXPECT_EQ(IccHelper::readIccColorGamut(iccBt709->getData(), iccBt709->getLength()),
+              ULTRAHDR_COLORGAMUT_BT709);
+
+    sp<DataStruct> iccP3 = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB, ULTRAHDR_COLORGAMUT_P3);
+    ASSERT_NE(iccP3->getLength(), 0);
+    ASSERT_NE(iccP3->getData(), nullptr);
+    EXPECT_EQ(IccHelper::readIccColorGamut(iccP3->getData(), iccP3->getLength()),
+              ULTRAHDR_COLORGAMUT_P3);
+
+    sp<DataStruct> iccBt2100 = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB,
+                                                          ULTRAHDR_COLORGAMUT_BT2100);
+    ASSERT_NE(iccBt2100->getLength(), 0);
+    ASSERT_NE(iccBt2100->getData(), nullptr);
+    EXPECT_EQ(IccHelper::readIccColorGamut(iccBt2100->getData(), iccBt2100->getLength()),
+              ULTRAHDR_COLORGAMUT_BT2100);
+}
+
+TEST_F(IccHelperTest, iccEndianness) {
+    sp<DataStruct> icc = IccHelper::writeIccProfile(ULTRAHDR_TF_SRGB, ULTRAHDR_COLORGAMUT_BT709);
+    size_t profile_size = icc->getLength() - kICCIdentifierSize;
+
+    uint8_t* icc_bytes = reinterpret_cast<uint8_t*>(icc->getData()) + kICCIdentifierSize;
+    uint32_t encoded_size = static_cast<uint32_t>(icc_bytes[0]) << 24 |
+                            static_cast<uint32_t>(icc_bytes[1]) << 16 |
+                            static_cast<uint32_t>(icc_bytes[2]) << 8 |
+                            static_cast<uint32_t>(icc_bytes[3]);
+
+    EXPECT_EQ(static_cast<size_t>(encoded_size), profile_size);
+}
+
+}  // namespace android::ultrahdr
+
diff --git a/libs/ultrahdr/tests/jpegdecoderhelper_test.cpp b/libs/ultrahdr/tests/jpegdecoderhelper_test.cpp
index c79dbe3..e2da01c 100644
--- a/libs/ultrahdr/tests/jpegdecoderhelper_test.cpp
+++ b/libs/ultrahdr/tests/jpegdecoderhelper_test.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <ultrahdr/jpegdecoderhelper.h>
+#include <ultrahdr/icc.h>
 #include <gtest/gtest.h>
 #include <utils/Log.h>
 
@@ -22,11 +23,19 @@
 
 namespace android::ultrahdr {
 
+// No ICC or EXIF
 #define YUV_IMAGE "/sdcard/Documents/minnie-320x240-yuv.jpg"
 #define YUV_IMAGE_SIZE 20193
+// Has ICC and EXIF
+#define YUV_ICC_IMAGE "/sdcard/Documents/minnie-320x240-yuv-icc.jpg"
+#define YUV_ICC_IMAGE_SIZE 34266
+// No ICC or EXIF
 #define GREY_IMAGE "/sdcard/Documents/minnie-320x240-y.jpg"
 #define GREY_IMAGE_SIZE 20193
 
+#define IMAGE_WIDTH 320
+#define IMAGE_HEIGHT 240
+
 class JpegDecoderHelperTest : public testing::Test {
 public:
     struct Image {
@@ -39,7 +48,7 @@
     virtual void SetUp();
     virtual void TearDown();
 
-    Image mYuvImage, mGreyImage;
+    Image mYuvImage, mYuvIccImage, mGreyImage;
 };
 
 JpegDecoderHelperTest::JpegDecoderHelperTest() {}
@@ -79,6 +88,10 @@
         FAIL() << "Load file " << YUV_IMAGE << " failed";
     }
     mYuvImage.size = YUV_IMAGE_SIZE;
+    if (!loadFile(YUV_ICC_IMAGE, &mYuvIccImage)) {
+        FAIL() << "Load file " << YUV_ICC_IMAGE << " failed";
+    }
+    mYuvIccImage.size = YUV_ICC_IMAGE_SIZE;
     if (!loadFile(GREY_IMAGE, &mGreyImage)) {
         FAIL() << "Load file " << GREY_IMAGE << " failed";
     }
@@ -91,6 +104,16 @@
     JpegDecoderHelper decoder;
     EXPECT_TRUE(decoder.decompressImage(mYuvImage.buffer.get(), mYuvImage.size));
     ASSERT_GT(decoder.getDecompressedImageSize(), static_cast<uint32_t>(0));
+    EXPECT_EQ(IccHelper::readIccColorGamut(decoder.getICCPtr(), decoder.getICCSize()),
+              ULTRAHDR_COLORGAMUT_UNSPECIFIED);
+}
+
+TEST_F(JpegDecoderHelperTest, decodeYuvIccImage) {
+    JpegDecoderHelper decoder;
+    EXPECT_TRUE(decoder.decompressImage(mYuvIccImage.buffer.get(), mYuvIccImage.size));
+    ASSERT_GT(decoder.getDecompressedImageSize(), static_cast<uint32_t>(0));
+    EXPECT_EQ(IccHelper::readIccColorGamut(decoder.getICCPtr(), decoder.getICCSize()),
+              ULTRAHDR_COLORGAMUT_BT709);
 }
 
 TEST_F(JpegDecoderHelperTest, decodeGreyImage) {
@@ -99,4 +122,35 @@
     ASSERT_GT(decoder.getDecompressedImageSize(), static_cast<uint32_t>(0));
 }
 
-}  // namespace android::ultrahdr
\ No newline at end of file
+TEST_F(JpegDecoderHelperTest, getCompressedImageParameters) {
+    size_t width = 0, height = 0;
+    std::vector<uint8_t> icc, exif;
+
+    JpegDecoderHelper decoder;
+    EXPECT_TRUE(decoder.getCompressedImageParameters(mYuvImage.buffer.get(), mYuvImage.size,
+                                                     &width, &height, &icc, &exif));
+
+    EXPECT_EQ(width, IMAGE_WIDTH);
+    EXPECT_EQ(height, IMAGE_HEIGHT);
+    EXPECT_EQ(icc.size(), 0);
+    EXPECT_EQ(exif.size(), 0);
+}
+
+TEST_F(JpegDecoderHelperTest, getCompressedImageParametersIcc) {
+    size_t width = 0, height = 0;
+    std::vector<uint8_t> icc, exif;
+
+    JpegDecoderHelper decoder;
+    EXPECT_TRUE(decoder.getCompressedImageParameters(mYuvIccImage.buffer.get(), mYuvIccImage.size,
+                                                     &width, &height, &icc, &exif));
+
+    EXPECT_EQ(width, IMAGE_WIDTH);
+    EXPECT_EQ(height, IMAGE_HEIGHT);
+    EXPECT_GT(icc.size(), 0);
+    EXPECT_GT(exif.size(), 0);
+
+    EXPECT_EQ(IccHelper::readIccColorGamut(icc.data(), icc.size()),
+              ULTRAHDR_COLORGAMUT_BT709);
+}
+
+}  // namespace android::ultrahdr