使用加速缩放 Ycbcr (420f) 时的伪像

我找不到任何有关如何调整 Ycbcr biplanar 大小的文档或示例，根据 Apple 的说法，Ycbcr biplanar 应该是您应该在 iOS 上使用的主要格式。我尝试像这样调整两个飞机的大小：

    // resize luma
    vImage_Buffer originalYBuffer = { CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0), CVPixelBufferGetHeightOfPlane(pixelBuffer, 0), CVPixelBufferGetWidthOfPlane(pixelBuffer, 0), CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0) };
    vImage_Buffer resizedYBuffer;
    vImageBuffer_Init(&resizedYBuffer, IMAGE_HEIGHT, IMAGE_WIDTH, 8 * sizeof(Pixel_8), kvImageNoFlags);
    error = vImageScale_Planar8(&originalYBuffer, &resizedYBuffer, NULL, kvImageNoFlags);
    assert(!error);
    cv::Mat grey(IMAGE_HEIGHT, IMAGE_WIDTH, CV_8UC1, resizedYBuffer.data);

    // resize chroma
    vImage_Buffer originalUVBuffer = { CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1), CVPixelBufferGetHeightOfPlane(pixelBuffer, 1), CVPixelBufferGetWidthOfPlane(pixelBuffer, 1), CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 1) };
    vImage_Buffer resizedUVBuffer;
    vImageBuffer_Init(&resizedUVBuffer, IMAGE_HEIGHT / 2, IMAGE_WIDTH / 2, 8 * sizeof(Pixel_16U), kvImageNoFlags);
    error = vImageScale_Planar8(&originalUVBuffer, &resizedUVBuffer, NULL, kvImageNoFlags);
    assert(!error);

但颜色完全无聊。亮度通道本身工作，所以这是色度的问题。这种格式应该使用 2 个字节来表示色度，但并不完全确定。如果我使用vImageScale_Planar8我的屏幕一半是绿色的，否则如果我使用vImageScale_Planar16U我的图像上到处都是蓝色/黄色噪点。

您可以使用vImageScale_CbCr8对于 UV 缓冲区，但它仅适用于 iOS 10+ ：

// resize luma
vImage_Buffer originalYBuffer = { CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0), CVPixelBufferGetHeightOfPlane(pixelBuffer, 0), CVPixelBufferGetWidthOfPlane(pixelBuffer, 0), CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0) };
vImage_Buffer resizedYBuffer;
vImageBuffer_Init(&resizedYBuffer, IMAGE_HEIGHT, IMAGE_WIDTH, 8 * sizeof(Pixel_8), kvImageNoFlags);
error = vImageScale_Planar(&originalYBuffer, &resizedYBuffer, NULL, kvImageNoFlags);
assert(!error);
cv::Mat grey(IMAGE_HEIGHT, IMAGE_WIDTH, CV_8UC1, resizedYBuffer.data);

// resize chroma
vImage_Buffer originalUVBuffer = { CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1), CVPixelBufferGetHeightOfPlane(pixelBuffer, 1), CVPixelBufferGetWidthOfPlane(pixelBuffer, 1), CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 1) };
vImage_Buffer resizedUVBuffer;
vImageBuffer_Init(&resizedUVBuffer, IMAGE_HEIGHT / 2, IMAGE_WIDTH / 2, 8 * sizeof(Pixel_16U), kvImageNoFlags);
error = vImageScale_CbCr8(&originalUVBuffer, &resizedUVBuffer, NULL, kvImageNoFlags);
assert(!error);