Force image decompression

SDWebImageDecoder.m

// https://github.com/rs/SDWebImage
// https://github.com/rs/SDWebImage/wiki/How-is-SDWebImage-better-than-X%3F

#import "SDWebImageDecoder.h"

@implementation UIImage (ForceDecode)

+ (UIImage *)decodedImageWithImage:(UIImage *)image
{	
    CGImageRef imageRef = image.CGImage;
    CGSize imageSize = CGSizeMake(CGImageGetWidth(imageRef), CGImageGetHeight(imageRef));
    CGRect imageRect = (CGRect){.origin = CGPointZero, .size = imageSize};

    CGColorSpaceRef colorSpace = CGImageGetColorSpace(imageRef);
    CGContextRef context = CGBitmapContextCreate(NULL, imageSize.width, imageSize.height, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpace, CGImageGetBitmapInfo(imageRef));

    // If failed, return undecompressed image
    if (!context) return image;

    CGContextDrawImage(context, imageRect, imageRef);
    CGImageRef decompressedImageRef = CGBitmapContextCreateImage(context);

    CGContextRelease(context);

    UIImage *decompressedImage = [UIImage imageWithCGImage:decompressedImageRef scale:image.scale orientation:image.imageOrientation];
    CGImageRelease(decompressedImageRef);
    return decompressedImage;
}

@end

SPOImageDecompression.m

// Código adaptado de aquí: https://gist.github.com/steipete/1144242

@implementation SPOImageDecompression

+ (UIImage *)decompressImage:(UIImage *)theIimage {
    CGImageRef image = theIimage.CGImage;
    
    // make a bitmap context of a suitable size to draw to, forcing decode
    size_t width = CGImageGetWidth(image);
    size_t height = CGImageGetHeight(image);
    
    CGColorSpaceRef colourSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef imageContext =  CGBitmapContextCreate(NULL, width, height, 8, width*4, colourSpace,
                                                       kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little);
    CGColorSpaceRelease(colourSpace);
    
    // draw the image to the context, release it
    CGContextDrawImage(imageContext, CGRectMake(0, 0, width, height), image);
    
    // now get an image ref from the context
    CGImageRef outputImage = CGBitmapContextCreateImage(imageContext);
    
    UIImage *cachedImage = [UIImage imageWithCGImage:outputImage];
    
    // clean up
    CGImageRelease(outputImage);
    CGContextRelease(imageContext);
    
    return cachedImage;
}

@end