SDImageCache.m

- (void)storeKeyToDisk:(NSString *)key
{
    UIImage *image = [[self imageFromKey:key fromDisk:YES] retain]; // be thread safe with no lock

    if (image != nil)
    {
		NSString *searchForMe = @"png";
		NSRange range = [key rangeOfString : searchForMe];
		if (range.location != NSNotFound) {			
			[[NSFileManager defaultManager] createFileAtPath:[self cachePathForKey:key] contents:UIImagePNGRepresentation(image) attributes:nil];
		} else {
			[[NSFileManager defaultManager] createFileAtPath:[self cachePathForKey:key] contents:UIImageJPEGRepresentation(image, (CGFloat)1.0) attributes:nil];
		}
		
        [image release];
    }
}