loading images from disk in iPhone app is slow

Question

In my iPhone app, I am using the iPhone\'s camera to take a photo and save it do disk (the application\'s documents folder). This is how i save it:

[UIImageJ         


        

Answer 1

This is the faster way I know. You'll need to import #import

I use this code to download and compress images during a scroll, inside a scrollview and you barely notice the delay.

CGImageSourceRef src = CGImageSourceCreateWithData((CFDataRef)mutableData, NULL);
CFDictionaryRef options = (CFDictionaryRef)[[NSDictionary alloc] initWithObjectsAndKeys:(id)kCFBooleanTrue, (id)kCGImageSourceCreateThumbnailWithTransform, (id)kCFBooleanTrue, (id)kCGImageSourceCreateThumbnailFromImageIfAbsent, (id)[NSNumber numberWithDouble:200.0], (id)kCGImageSourceThumbnailMaxPixelSize, nil];
CGImageRef thumbnail = CGImageSourceCreateThumbnailAtIndex(src, 0, options);

UIImage *image = [[UIImage alloc] initWithCGImage:thumbnail];
// Cache
NSString *fileName = @"fileName.jpg";
NSString *path = [NSTemporaryDirectory() stringByAppendingPathComponent:@"thumbnail"];
path = [path stringByAppendingPathComponent:fileName];
if ([UIImagePNGRepresentation(image) writeToFile:path atomically:YES]) {
    // Success
}