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@takuma104
Created December 18, 2009 08:07
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@interface UIImage(ImmediateLoad)
+ (UIImage*)imageImmediateLoadWithContentsOfFile:(NSString*)path;
@end
@implementation UIImage(ImmediateLoad)
+ (UIImage*)imageImmediateLoadWithContentsOfFile:(NSString*)path {
UIImage *image = [[UIImage alloc] initWithContentsOfFile:path];
CGImageRef imageRef = [image CGImage];
CGRect rect = CGRectMake(0.f, 0.f, CGImageGetWidth(imageRef), CGImageGetHeight(imageRef));
CGContextRef bitmapContext = CGBitmapContextCreate(NULL,
rect.size.width,
rect.size.height,
CGImageGetBitsPerComponent(imageRef),
CGImageGetBytesPerRow(imageRef),
CGImageGetColorSpace(imageRef),
CGImageGetBitmapInfo(imageRef)
);
CGContextDrawImage(bitmapContext, rect, imageRef);
CGImageRef decompressedImageRef = CGBitmapContextCreateImage(bitmapContext);
UIImage *decompressedImage = [UIImage imageWithCGImage:decompressedImageRef];
CGImageRelease(decompressedImageRef);
CGContextRelease(bitmapContext);
[image release];
return decompressedImage;
}
@end
@bdudney
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bdudney commented Mar 29, 2012

Hi Steve, I'm pretty sure that the imageRef will also have an internal pointer to the decompressed bits. You could just create a new context with the UIKit functions, draw image then discard the context. The UIImage image would then have an indirect pointer to the decompressed image.

@dannybabiy
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The snippet works on my iphone, but then in the simulator it doesn't work. I get something like : CGBitmapContextCreate: unsupported parameter combination: 8 integer bits/component; 24 bits/pixel; 3-component color space; kCGImageAlphaNone; 1440 bytes/row.

I noticed that for the same troubled image, on the device CGImageGetBytesPerRow(imageRef) == 1920 and width*4 == 1920, but in the simulator CGImageGetBytesPerRow(imageRef) == 1440.

I then tried what steipete suggested and it works on both the device and simulator. Thoughts?

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