message: Added util func to check if dim signature.
diff: @@ -84,7 +84,8 @@ class ImagePreprocessor : public Preprocessor {
  private:
  using Preprocessor::Preprocessor;
  -
  + // Returns true if the model expects dynamic image shape, false otherwise.
  + bool IsInputImageDynamic();
  // Returns false if image preprocessing could be skipped, true otherwise.
  bool IsImagePreprocessingNeeded(const vision::FrameBuffer& frame_buffer,
  const vision::BoundingBox& roi);
  