@Override
        public void onFinalImageSet(
            long id, int imageOrigin, @Nullable ImageInfo imageInfo, @Nullable Drawable drawable) {
          mImageInfo = imageInfo;
          mSelectedRegion.setUpdateMaximumDimensionOnNextSizeChange(true);
          if (imageInfo != null) {
            mFullImageView.setAspectRatio(imageInfo.getWidth() / (float) imageInfo.getHeight());
            mFullImageView.requestLayout();
            updateRegion();
          }
        }
Simple region decoding example that renders the original image and a selected region.
samples/showcase/src/main/java/com/facebook/fresco/samples/showcase/imagepipeline/ImagePipelineRegionDecodingFragment.java