我正在使用以下代码在xcode中创建GIF:

NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:nil];
NSURL *fileURL = [documentsDirectoryURL URLByAppendingPathComponent:@"animated.gif"];
CGImageDestinationRef destination = CGImageDestinationCreateWithURL((__bridge CFURLRef)fileURL, kUTTypeGIF, imageArray.count, NULL);

NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithCapacity:5];

NSDictionary *frameProperties = [NSDictionary dictionaryWithObject:dict forKey:(NSString *)kCGImagePropertyPNGDictionary];

NSMutableDictionary *dict2 = [NSMutableDictionary dictionaryWithCapacity:5];

const uint8_t colorTable2[9] = {0, 0, 0, 128, 128, 128, 255,255,255};
NSData *colorTableData2 = [NSData dataWithBytes:colorTable2 length:9];

[dict2 setObject:colorTableData2 forKey:(NSString *)kCGImagePropertyGIFImageColorMap];
[dict2 setObject:[NSNumber numberWithInt:0] forKey:(NSString *)kCGImagePropertyGIFLoopCount];
[dict2 setObject:[NSNumber numberWithFloat:0.005] forKey:(NSString *)kCGImagePropertyGIFDelayTime];

NSDictionary *gifProperties = [NSDictionary dictionaryWithObject:dict2 forKey:(NSString *) kCGImagePropertyGIFDictionary];

for (int i = 0; i < imageArray.count; i++) {
    UIImage *image = [UIImage imageWithContentsOfFile:[imageArray objectAtIndex:i]];
    CGImageDestinationAddImage(destination, image.CGImage, (__bridge CFDictionaryRef)frameProperties);
}

CGImageDestinationSetProperties(destination, (__bridge CFDictionaryRef)gifProperties);
CGImageDestinationFinalize(destination);
CFRelease(destination);

这里的问题是,如果imageArray.count小于23,则输出GIF将不包含颜色失真。如果大于22,则颜色失真将以具有背景色而不是其原始颜色的图像斑块的形式发生。

我认为我没有设置任何代码来执行图像压缩,所以我不确定为什么会这样。如果有人可以对此问题提供一些见解,那将对我有很大帮助。

编辑:
我保存了每个单独的框架,以确保颜色失真不是由于框架本身引起的。因此,我认为这与CG框架有关。

谢谢。

最佳答案

尝试使用ImageIO.framework框架在iOS APP中使用GIF,我的GIF图像也会出现变形,但是后来我使用了这种方法,它们很好

NSURL *url1 = [[NSBundle mainBundle] URLForResource:@"YourImage" withExtension:@"gif"];

self.imageView.image = [UIImage animatedImageWithAnimatedGIFData:[NSData dataWithContentsOfURL:url1]];

他们在这之后很好

关于ios - 当GIF包含大量帧时,Xcode GIF输出的颜色失真,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/24906092/

10-14 23:40