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POConvert UIImage to CVImageBufferRef
 

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    <p>This code mostly works, but the resulting data seems to loose a color channel (is what I am thinking) as the resulting image data when displayed is tinted blue!</p> <p>Here is the code:</p> <pre><code>UIImage* myImage=[UIImage imageNamed:@"sample1.png"]; CGImageRef imageRef=[myImage CGImage]; CVImageBufferRef pixelBuffer = [self pixelBufferFromCGImage:imageRef]; </code></pre> <p>The method pixelBufferFromCGIImage was grabbed from another post on stackoverflow here: <a href="https://stackoverflow.com/questions/3741323/how-do-i-export-uiimage-array-as-a-movie">How do I export UIImage array as a movie?</a> (although this application is unrelated to what I am trying to do) it is</p> <pre><code>+ (CVPixelBufferRef)pixelBufferFromCGImage:(CGImageRef)image { CGSize frameSize = CGSizeMake(CGImageGetWidth(image), CGImageGetHeight(image)); NSDictionary *options = @{ (__bridge NSString *)kCVPixelBufferCGImageCompatibilityKey: @(NO), (__bridge NSString *)kCVPixelBufferCGBitmapContextCompatibilityKey: @(NO) }; CVPixelBufferRef pixelBuffer; CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, frameSize.width, frameSize.height, kCVPixelFormatType_32ARGB, (__bridge CFDictionaryRef) options, &amp;pixelBuffer); if (status != kCVReturnSuccess) { return NULL; } CVPixelBufferLockBaseAddress(pixelBuffer, 0); void *data = CVPixelBufferGetBaseAddress(pixelBuffer); CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(data, frameSize.width, frameSize.height, 8, CVPixelBufferGetBytesPerRow(pixelBuffer), rgbColorSpace, (CGBitmapInfo) kCGImageAlphaNoneSkipLast); CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image), CGImageGetHeight(image)), image); CGColorSpaceRelease(rgbColorSpace); CGContextRelease(context); CVPixelBufferUnlockBaseAddress(pixelBuffer, 0); return pixelBuffer; } </code></pre> <p>I am thinking it has something to do with the relationship between kCVPixelFormatType_32ARGB and kCGImageAlphaNoneSkipLast though I have tried every combination and get either the same result or a application crash. Once again, this gets the UIImage data into CVImageBufferRef but when I display the image on screen, it appears to loose a color channel and shows up tinted blue. The image is a png.</p>
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