How to convert YCbCr_420 to BGR

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

I’m adapting the sample code yuvjpeg to be able to process the video with opencv. I’m stuck at converting the frames to BGR.

The frames are in PIXEL_FMT_YCbCr_420_888 format. There appear to be 2 buffers with each frame. The output of yuvjpeg follows:

CONSUMER: Acquired Frame: 20, time 24585281973
CONSUMER: 	Sensor Timestamp: 24585244997000, LUX: 8.522511
CONSUMER: 	IImage(2D): buffer 0 (640x480, 640 stride), 07 09 0a 08 07 08 09 0d 09 05 07 0d
CONSUMER: 	IImage(2D): buffer 1 (320x240, 640 stride), 7b 88 87 89 7a 84 7c 86 7c 8a 7c 80
CONSUMER: 	Wrote JPEG: 20.JPG

The code that generates this output is:

// Print out image details, and map the buffers to read out some data.
       Image *image = iFrame->getImage();
        IImage *iImage = interface_cast<IImage>(image);
        IImage2D *iImage2D = interface_cast<IImage2D>(image);
        for (uint32_t i = 0; i < iImage->getBufferCount(); i++)
        {
            const uint8_t *d = static_cast<const uint8_t*>(iImage->mapBuffer(i));
            if (!d)
                ORIGINATE_ERROR("\tFailed to map buffer\n");

            Size2D<uint32_t> size = iImage2D->getSize(i);
            CONSUMER_PRINT("\tIImage(2D): "
                           "buffer %u (%ux%u, %u stride), "
                           "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
                           i, size.width(), size.height(), iImage2D->getStride(i),
                           d[0], d[1], d[2], d[3], d[4], d[5],
                           d[6], d[7], d[8], d[9], d[10], d[11]);
        }

Thanks for any ideas.

2

What’s your purpose to convert to BGR?

3

I have some opencv code to process the frames so need to convert to BGR in order to create cv::Mat. I know it’s not the most efficient thing to do in the Argus world, but I’m need some quick results with our current opencv code. I use Argus because I can control the camera exposure, analog and digital gain.

4

Please refer to [url]https://devtalk.nvidia.com/default/topic/1037863/jetson-tx2/argus-and-opencv/post/5273400/#5273400[/url]