ios Decode part of an image
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I have a big image which is too big to be loaded into memory but i am only interested in a sub set of pixels within that big image. Is it possible to decode into memory only this subset of pixels? I know that in Android there is a class in the API to do exactly this called BitmapRegionDecoder are something like that

I found CGDataProviderCreateSequential but it needs the raw pixels in the constructor...

Right now i am doing something like this : 

    UIImage* srcImage = ...;
        CFDataRef cgImgDataRef = CGDataProviderCopyData(CGImageGetDataProvider(srcImage.CGImage));//After this call, all pixels are decoded into memory and the app crashes
    char* imageData = (char*)CFDataGetBytePtr(cgImgDataRef);
