diff --git a/libs/ultrahdr/jpegr.cpp b/libs/ultrahdr/jpegr.cpp
index c250aa0..366706a 100644
--- a/libs/ultrahdr/jpegr.cpp
+++ b/libs/ultrahdr/jpegr.cpp
@@ -145,7 +145,8 @@
     return ERROR_JPEGR_INVALID_NULL_PTR;
   }
 
-  if (hdr_tf <= ULTRAHDR_TF_UNSPECIFIED || hdr_tf > ULTRAHDR_TF_MAX) {
+  if (hdr_tf <= ULTRAHDR_TF_UNSPECIFIED || hdr_tf > ULTRAHDR_TF_MAX
+          || hdr_tf == ULTRAHDR_TF_SRGB) {
     ALOGE("Invalid hdr transfer function %d", hdr_tf);
     return ERROR_JPEGR_INVALID_INPUT_TYPE;
   }
@@ -509,11 +510,6 @@
     return ERROR_JPEGR_INVALID_INPUT_TYPE;
   }
 
-  if (gain_map != nullptr && gain_map->data == nullptr) {
-    ALOGE("received nullptr address for gain map data");
-    return ERROR_JPEGR_INVALID_INPUT_TYPE;
-  }
-
   if (output_format == ULTRAHDR_OUTPUT_SDR) {
     JpegDecoderHelper jpeg_decoder;
     if (!jpeg_decoder.decompressImage(compressed_jpegr_image->data, compressed_jpegr_image->length,
@@ -555,6 +551,11 @@
   if (!gain_map_decoder.decompressImage(compressed_map.data, compressed_map.length)) {
     return ERROR_JPEGR_DECODE_ERROR;
   }
+  if ((gain_map_decoder.getDecompressedImageWidth() *
+       gain_map_decoder.getDecompressedImageHeight()) >
+      gain_map_decoder.getDecompressedImageSize()) {
+    return ERROR_JPEGR_CALCULATION_ERROR;
+  }
 
   if (gain_map != nullptr) {
     gain_map->width = gain_map_decoder.getDecompressedImageWidth();
@@ -584,6 +585,11 @@
   if (!jpeg_decoder.decompressImage(compressed_jpegr_image->data, compressed_jpegr_image->length)) {
     return ERROR_JPEGR_DECODE_ERROR;
   }
+  if ((jpeg_decoder.getDecompressedImageWidth() *
+       jpeg_decoder.getDecompressedImageHeight() * 3 / 2) >
+      jpeg_decoder.getDecompressedImageSize()) {
+    return ERROR_JPEGR_CALCULATION_ERROR;
+  }
 
   if (exif != nullptr) {
     if (exif->data == nullptr) {
@@ -605,7 +611,6 @@
   uncompressed_yuv_420_image.data = jpeg_decoder.getDecompressedImagePtr();
   uncompressed_yuv_420_image.width = jpeg_decoder.getDecompressedImageWidth();
   uncompressed_yuv_420_image.height = jpeg_decoder.getDecompressedImageHeight();
-
   JPEGR_CHECK(applyGainMap(&uncompressed_yuv_420_image, &map, &uhdr_metadata, output_format,
                            max_display_boost, dest));
   return NO_ERROR;
@@ -848,6 +853,20 @@
     return ERROR_JPEGR_INVALID_NULL_PTR;
   }
 
+  // TODO: remove once map scaling factor is computed based on actual map dims
+  size_t image_width = uncompressed_yuv_420_image->width;
+  size_t image_height = uncompressed_yuv_420_image->height;
+  size_t map_width = image_width / kMapDimensionScaleFactor;
+  size_t map_height = image_height / kMapDimensionScaleFactor;
+  map_width = static_cast<size_t>(
+          floor((map_width + kJpegBlock - 1) / kJpegBlock)) * kJpegBlock;
+  map_height = ((map_height + 1) >> 1) << 1;
+  if (map_width != uncompressed_gain_map->width
+   || map_height != uncompressed_gain_map->height) {
+    ALOGE("gain map dimensions and primary image dimensions are not to scale");
+    return ERROR_JPEGR_INVALID_INPUT_TYPE;
+  }
+
   dest->width = uncompressed_yuv_420_image->width;
   dest->height = uncompressed_yuv_420_image->height;
   ShepardsIDW idwTable(kMapDimensionScaleFactor);