Motivation:

When you're attempting to get an Image from ImageReader or ImageAnalysis.Analyzer you actually get 3 separate ByteBuffers which you can't pass to further processing. You have to merge them but that also is not easy because they are full of row and pixel strides.

Solution:

This library carefully merges 3 buffers into one with respect to all strides. As a result, you receive YUV type (NV21 or YUV_420) and ByteBuffer to pass into OpenCV or a neural network framework.

The whole library is a single file, you can just copy Yuv.java into your project.

Alternatives

1. (For OpenCV users) Copy private method from OpenCV camera implementation: JavaCamera2View, Mat rgba().
2. Capture image from camera directly to RenderScript Allocation.getSurface();
3. Switch back to CameraApi 1 (some trade offs);
4. Manipulate pixels manually as it has done in TFLite demo ImageUtils. However, even with C++ implementation it's ridiculously slow. ~50ms for image about 1280x720 on Snapdragon 855;

• make the library;
• write unit tests;
• add RenderScript example;
• add OpenCV example;
• publish to jcenter;
• add MNN example;
• add TFLite example.