What's the most efficient way to check of CVPixelBufferRef has white pixels?

Question

Below is the code that I'm currently using, but it's not returning an white pixels, when a photo clearly has white pixels.

const int kBytesPerPixel = 4;
        CVPixelBufferLockBaseAddress( pixelBuffer, 0 );
        int bufferWidth = (int)CVPixelBufferGetWidth( pixelBuffer );
        int bufferHeight = (int)CVPixelBufferGetHeight( pixelBuffer );
        size_t bytesPerRow = CVPixelBufferGetBytesPerRow( pixelBuffer );
        uint8_t *baseAddress = CVPixelBufferGetBaseAddress( pixelBuffer );


        int count = 0;
        BOOL hasWhitePixels = NO;
        for ( int row = 0; row < bufferHeight; row++ ){
            uint8_t *pixel = baseAddress + row * bytesPerRow;
            for ( int column = 0; column < bufferWidth; column++ ){
                if (pixel[0] == 255 && pixel[1] == 255 && pixel[2] == 255) {
                    count++;
                    hasWhitePixels = YES;
                    NSLog(@"HAS WHITE PIXELS");
                    break;
                }
                pixel += kBytesPerPixel;

            }
        }

        CVPixelBufferUnlockBaseAddress( pixelBuffer, 0 );

Are you sure those pixels are "pure white" (255,255,255)? Perhaps you should be checking with some tolerance? — Kamil.S, Aug 08 '17 at 15:38
Maybe the pixels aren't arriving in RGBA order. Did you see this: https://stackoverflow.com/questions/7895856/pixel-formats-cvpixelbufferrefs-and-glreadpixels?rq=1 ? — Kamil.S, Aug 08 '17 at 21:15

What's the most efficient way to check of CVPixelBufferRef has white pixels?

0 Answers0