我想使用QTKit.framework将所有帧写入磁盘以进行相机输入.但我得到的所有图像都是半透明的,没有一些颜色,可能是颜色空间问题？ (
它们在预览视图中似乎很好但是当我写它们时“发生了什么”.
我不知道那是什么.
它们在预览视图中似乎很好但是当我写它们时“发生了什么”.
我不知道那是什么.
-(void)savePNGImage:(CGImageRef)imageRef path:(NSString *)path {
NSURL *outURL = [[NSURL alloc] initFileURLWithPath:path];
CGImageDestinationRef dr = CGImageDestinationCreateWithURL ((CFURLRef)outURL,(CFStringRef)@"public.png",1,NULL);
CGImageDestinationAddImage(dr,imageRef,NULL);
CGImageDestinationFinalize(dr);
[outURL release];
}
-(void)saveJPEGImage:(CGImageRef)imageRef path:(NSString *)path {
CFMutableDictionaryRef mSaveMetaAndOpts = CFDictionaryCreateMutable(nil,&kcfTypeDictionaryKeyCallBacks,&kcfTypeDictionaryValueCallBacks);
CFDictionarySetValue(mSaveMetaAndOpts,kCGImageDestinationLossyCompressionQuality,[NSNumber numberWithFloat:1.0]); // set the compression quality here
NSURL *outURL = [[NSURL alloc] initFileURLWithPath:path];
CGImageDestinationRef dr = CGImageDestinationCreateWithURL ((CFURLRef)outURL,(CFStringRef)@"public.jpeg",mSaveMetaAndOpts);
CGImageDestinationFinalize(dr);
[outURL release];
}
- (void)captureOutput:(QTCaptureOutput *)captureOutput
didOutputVideoFrame:(CVImageBufferRef)videoFrame
withSampleBuffer:(QTSampleBuffer *)sampleBuffer
fromConnection:(QTCaptureConnection *)connection{
CVPixelBufferLockBaseAddress(videoFrame,0);
uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(videoFrame);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(videoFrame);
size_t width = CVPixelBufferGetWidth(videoFrame);
size_t height = CVPixelBufferGetHeight(videoFrame);
CVPixelBufferUnlockBaseAddress(videoFrame,0);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef newContext = CGBitmapContextCreate(baseAddress,width,height,8,bytesPerRow,colorSpace,kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
CGImageRef frame = CGBitmapContextCreateImage(newContext);
CGContextRelease(newContext);
CGColorSpaceRelease(colorSpace);
[self savePNGImage:frame path:[NSString stringWithFormat:@"/Users/nacho4d/Desktop/framesCam/frame%003d.png",frameNum++]];
[self saveJPEGImage:frame path:[NSString stringWithFormat:@"/Users/nacho4d/Desktop/framesCam/frame%003d.jpeg",frameNum++]];
CGImageRelease(frame);
}
Capturer属性只是帧大小和像素格式,如下所示：
[NSNumber numberWithUnsignedInt：kCVPixelFormatType_32ARGB],(id)kCVPixelBufferPixelFormatTypeKey
更新：
我也试过JPEG,我也得到了同样的图像,就像图像中缺少一些通道一样,所有写入的帧都有白色背景. (因为JPEG不允许透明？)
原始和书面(JPEG)一：
(我不显示PNG,因为它是透明的,很难在浏览器中看到)
提前致谢.
解决方法
我不确定你的问题是什么,但这是我如何将图像保存到磁盘.只需传入您从委托方法获得的CVImageBufferRef,当然还有自己的URL,它应该可以正常工作.至少它对我有用.祝好运！
-(void)saveImage:(CVImageBufferRef)image toURL:(NSURL*)url{
NSCIImageRep *imageRep = [NSCIImageRep imageRepWithCIImage:[CIImage imageWithCVImageBuffer:image]];
NSImage *_image = [[NSImage alloc] initWithSize:[imageRep size]];
[_image addRepresentation:imageRep];
NSData *bitmapData = [_image TIFFRep resentation];
NSBitmapImageRep *bitmapRep = [NSBitmapImageRep imageRepWithData:bitmapData];
NSData *imageData = [bitmapRep representationUsingType:NSJPEGFileType properties:nil];
[_image release];
_image = [[NSImage alloc] initWithData:imageData];
NSBitmapImageRep *imgRep = [[_image representations] objectAtIndex: 0];
NSData *data = [imgRep representationUsingType: NSPNGFileType properties: nil];
[data writeToFile: [self getSaveString] atomically: NO];
[_image release];
}