/*
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* This file is part of the SDWebImage package.
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* (c) Olivier Poitrey <rs@dailymotion.com>
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*
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* Created by james <https://github.com/mystcolor> on 9/28/11.
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*
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* For the full copyright and license information, please view the LICENSE
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* file that was distributed with this source code.
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*/
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#import "SDWebImageDecoder.h"
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@implementation UIImage (ForceDecode)
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+ (UIImage *)decodedImageWithImage:(UIImage *)image {
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// while downloading huge amount of images
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// autorelease the bitmap context
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// and all vars to help system to free memory
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// when there are memory warning.
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// on iOS7, do not forget to call
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// [[SDImageCache sharedImageCache] clearMemory];
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@autoreleasepool{
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// do not decode animated images
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if (image.images) { return image; }
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CGImageRef imageRef = image.CGImage;
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CGImageAlphaInfo alpha = CGImageGetAlphaInfo(imageRef);
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BOOL anyAlpha = (alpha == kCGImageAlphaFirst ||
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alpha == kCGImageAlphaLast ||
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alpha == kCGImageAlphaPremultipliedFirst ||
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alpha == kCGImageAlphaPremultipliedLast);
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if (anyAlpha) { return image; }
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size_t width = CGImageGetWidth(imageRef);
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size_t height = CGImageGetHeight(imageRef);
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// current
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CGColorSpaceModel imageColorSpaceModel = CGColorSpaceGetModel(CGImageGetColorSpace(imageRef));
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CGColorSpaceRef colorspaceRef = CGImageGetColorSpace(imageRef);
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bool unsupportedColorSpace = (imageColorSpaceModel == 0 || imageColorSpaceModel == -1 || imageColorSpaceModel == kCGColorSpaceModelCMYK || imageColorSpaceModel == kCGColorSpaceModelIndexed);
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if (unsupportedColorSpace)
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colorspaceRef = CGColorSpaceCreateDeviceRGB();
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CGContextRef context = CGBitmapContextCreate(NULL, width,
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height,
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CGImageGetBitsPerComponent(imageRef),
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0,
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colorspaceRef,
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kCGBitmapByteOrderDefault | kCGImageAlphaPremultipliedFirst);
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// Draw the image into the context and retrieve the new image, which will now have an alpha layer
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CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
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CGImageRef imageRefWithAlpha = CGBitmapContextCreateImage(context);
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UIImage *imageWithAlpha = [UIImage imageWithCGImage:imageRefWithAlpha scale:image.scale orientation:image.imageOrientation];
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if (unsupportedColorSpace)
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CGColorSpaceRelease(colorspaceRef);
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CGContextRelease(context);
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CGImageRelease(imageRefWithAlpha);
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return imageWithAlpha;
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}
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}
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@end
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