message: Correct the size of downsampledFrame
  The frameWidth and frameHeight should be both considered when determining the size of downsampledFrame.
  The previous code used frameWidth, potentially causing an illegal memory access.
diff: @@ -244,7 +244,7 @@ public class ObjectTracker {
  new byte
  [(frameWidth + DOWNSAMPLE_FACTOR - 1)
  / DOWNSAMPLE_FACTOR
  - * (frameWidth + DOWNSAMPLE_FACTOR - 1)
  + * (frameHeight + DOWNSAMPLE_FACTOR - 1)
  / DOWNSAMPLE_FACTOR];
  }
  