Skip to content

Instantly share code, notes, and snippets.

@orta
Created September 13, 2012 16:32
Embed
What would you like to do?
//
// UIImage+ImmediateLoading.h
// Code taken from https://gist.github.com/259357
//
#import <Foundation/Foundation.h>
@interface UIImage (UIImage_ImmediateLoading)
- (UIImage*) initImmediateLoadWithContentsOfFile:(NSString*)path;
+ (UIImage*)imageImmediateLoadWithContentsOfFile:(NSString*)path;
@end
//
// UIImage+ImmediateLoading.h
// Code taken from https://gist.github.com/259357
//
#import "UIImage+ImmediateLoading.h"
@implementation UIImage (UIImage_ImmediateLoading)
+ (UIImage*)imageImmediateLoadWithContentsOfFile:(NSString*)path {
return [[UIImage alloc] initImmediateLoadWithContentsOfFile: path] ;
}
- (UIImage*) initImmediateLoadWithContentsOfFile:(NSString*)path {
UIImage *image = [[UIImage alloc] initWithContentsOfFile:path];
if(!image) return nil;
CGImageRef imageRef = [image CGImage];
CGColorSpaceRef gray = CGColorSpaceCreateDeviceGray();
CGColorSpaceRef colorSpace = CGImageGetColorSpace(imageRef);
//Stack Overflow and this original gist tell us kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little
// is required for the work to stay off the main thread but we can't source this
//Considering you can't create a bitmap context for a grayscale with those flags,
//we'll take out chances this way
CGBitmapInfo info;
if (colorSpace == gray) {
info = kCGImageAlphaNone;
} else {
info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little;
}
CGColorSpaceRelease(gray);
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),
colorSpace,
info
);
CGContextDrawImage(bitmapContext, rect, imageRef);
CGImageRef decompressedImageRef = CGBitmapContextCreateImage(bitmapContext);
UIImage* decompressedImage = [[UIImage alloc] initWithCGImage: decompressedImageRef];
CGImageRelease(decompressedImageRef);
CGContextRelease(bitmapContext);
return decompressedImage;
}
@end
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment