Ios 使用CGImageDestinationCopyImageSource时,CGImageDestinationFinalize失败
我试图复制uiimage并更改元数据,而不重新编码该映像,以避免造成jpg瑕疵(我知道reencodes下面的代码,但这只是为了让它可以运行以进行测试)。CGImageDestinationCopyImageSource应该在不重新编码的情况下复制图像源,但当我使用该函数时,它在CGImageDestinationFinalize时失败。我正试图遵循这个技术说明 你知道为什么CGImageDestinationFinalize会因为下面的代码而失败吗Ios 使用CGImageDestinationCopyImageSource时,CGImageDestinationFinalize失败,ios,core-foundation,Ios,Core Foundation,我试图复制uiimage并更改元数据,而不重新编码该映像,以避免造成jpg瑕疵(我知道reencodes下面的代码,但这只是为了让它可以运行以进行测试)。CGImageDestinationCopyImageSource应该在不重新编码的情况下复制图像源,但当我使用该函数时,它在CGImageDestinationFinalize时失败。我正试图遵循这个技术说明 你知道为什么CGImageDestinationFinalize会因为下面的代码而失败吗 -(NSData *)copyImageAn
-(NSData *)copyImageAndChangeMetaData:(UIImage *)image {
NSData *imageData = UIImageJPEGRepresentation(image, 1.0);
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)imageData, NULL);
NSLog(@" source: 0x%x", source);
if (source == NULL) {
NSLog(@" source is NULL");
}
CFStringRef UTI = CGImageSourceGetType(source);
NSLog(@" UTI: %@", (__bridge NSString *)UTI);
if (UTI == NULL) {
NSLog(@" UTI is NULL");
}
NSMutableData *dest_data = [NSMutableData data];
CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)dest_data, UTI, 1, NULL);
if (!destination)
{
NSLog(@"Image Data Error: Could not create image destination");
}
CFMutableDictionaryRef metadata = CFDictionaryCreateMutable(kCFAllocatorDefault, 2, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
int orient = 8;
CFNumberRef orientRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &orient);
CFDictionarySetValue(metadata, kCGImageDestinationOrientation, orientRef);
CFStringRef dateStringRef = CFStringCreateWithCString(kCFAllocatorDefault, "2017-06-06T17:31:46Z", kCFStringEncodingASCII);
CFDictionarySetValue(metadata, kCGImageDestinationDateTime, dateStringRef);
CFErrorRef errorRef = nil;
if (!CGImageDestinationCopyImageSource(destination, source, metadata, &errorRef)) {
CFStringRef error_description = CFErrorCopyDescription(errorRef);
NSString *errorDescription = (__bridge NSString *)error_description;
NSLog(@"Image Data Error: Error copying image data: %@", errorDescription);
CFRelease(error_description);
}
BOOL success = NO;
success = CGImageDestinationFinalize(destination);
if (!success)
{
NSLog(@"Image Data Error: Could not finalize image");
}
if (source != NULL) {
CFRelease(source);
}
if (destination != NULL) {
CFRelease(destination);
}
return dest_data;
}
根据苹果公司的HeaderDoc文档,文件
中的cImageDestinationCopyImageSource()
函数:
之后不应调用CGImageDestinationFinalize()-此函数返回时,结果将保存到目标
从各方面考虑,这是一个非常奇怪的API。