错误的接收器类型“CGImageRef”（又名“CGImage *”）

Posted 2023-03-07

【中文标题】错误的接收器类型“CGImageRef”（又名“CGImage *”）

【英文标题】：Bad receiver type 'CGImageRef' (aka 'CGImage *')

【发布时间】：2016-05-04 17:07:52

【问题描述】：

我是一名 ios 初学者，正在关注 How can I manipulate the pixel values in a CGImageRef in Xcode 学习更改 CGImages。我稍微更改了代码，以便图像中的中间像素应该被涂成红色，而不是为每个像素交换蓝色和红色缓冲区。

但是现在我在发送消息时收到“错误的接收器类型'CGImageRef'（又名'CGImage *'）”错误

    manipulated = [imageRef colorMiddle];

在这个函数中：

    - (void)renderColorFrame:(CMSampleBufferRef)sampleBuffer
     

 CVImageBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(pixelBuffer, 0);

size_t cols = CVPixelBufferGetWidth(pixelBuffer);
size_t rows = CVPixelBufferGetHeight(pixelBuffer);
    
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

unsigned char *ptr = (unsigned char *) CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);

NSData *data = [[NSData alloc] initWithBytes:ptr length:rows*cols*4];
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);

CGBitmapInfo bitmapInfo;
bitmapInfo = (CGBitmapInfo)kCGImageAlphaNoneSkipFirst;
bitmapInfo |= kCGBitmapByteOrder32Little;

CGDataProviderRef provider = CGDataProviderCreateWithCFData((CFDataRef)data);

CGImageRef imageRef = CGImageCreate(cols,
                                    rows,
                                    8,
                                    8 * 4,
                                    cols*4,
                                    colorSpace,
                                    bitmapInfo,
                                    provider,
                                    NULL,
                                    false,
                                    kCGRenderingIntentDefault);



//hier image ref verarbeiten!!
manipulated = [imageRef colorMiddle]; //here

leftImage = CGImageCreateWithImageInRect(imageRef, CGRectMake(0, 0, self.view.frame.size.width * 6/7, self.view.frame.size.height));

rightImage = CGImageCreateWithImageInRect(imageRef, CGRectMake(self.view.frame.size.width / 7, 0, self.view.frame.size.width * 6/7, self.view.frame.size.height));

    //left image
_colorImageViewL.image = [[UIImage alloc] initWithCGImage:leftImage/*imageRef*/];
    
    //right image
_colorImageViewR.image = [[UIImage alloc]initWithCGImage:rightImage/*imageRef*/];

//Full
 //  _colorImageViewFull.image = [[UIImage alloc]initWithCGImage:imageRef];


CGImageRelease(imageRef);
CGImageRelease(leftImage);
CGImageRelease(rightImage);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);

我不明白为什么我会在此处收到此错误，因为应该使用匹配的参数发送消息：

        @interface ViewController () <AVCaptureVideoDataOutputSampleBufferDelegate> 
        
        STSensorController *_sensorController;
        
        AVCaptureSession *_avCaptureSession;
        AVCaptureDevice *_videoDevice;
    
        UIImageView *_depthImageView;
        //UIImageView *_depthImageView2;
        //UIImageView *_normalsImageView;
        
        //Left
        UIImageView *_colorImageViewL;
        
        //right
        UIImageView *_colorImageViewR;
        
        //Full
        //UIImageView *_colorImageViewFull;
        
        uint16_t *_linearizeBuffer;
        uint8_t *_coloredDepthBuffer;
        uint8_t *_normalsBuffer;
        
        STNormalEstimator *_normalsEstimator;
        
        UILabel* _statusLabel;
        
        GLKMatrix4 _projection;
        
        CGImageRef leftImage;
        CGImageRef rightImage;
        CGImageRef manipulated;
        
       
        
        
        AppStatus _appStatus;

    
    
    - (BOOL)connectAndStartStreaming;
    - (void)renderDepthFrame:(STDepthFrame*)depthFrame;
    - (void)renderNormalsFrame:(STDepthFrame*)normalsFrame;
    - (void)renderColorFrame:(CMSampleBufferRef)sampleBuffer;
    - (void)setupColorCamera;
    - (void)startColorCamera;
    - (void)stopColorCamera;
    - (CGImageRef)colorMiddle:(CGImageRef)image; //here

@end 

有谁知道导致错误的原因以及如何解决此问题？ 我只是想不出任何东西，因为使用 CGImageRefs 的其他所有东西都可以正常工作，据我所知，这应该是正确的做法。

请看一下这个问题的糟糕表现，因为我仍然需要学习如何正确格式化所有内容。

提前致谢！

【参考方案1】：

您的线路：

manipulated = [imageRef colorMiddle];

需要：

manipulated = [self colorMiddle:imageRef];

colorMiddle: 是 ViewController 类的一个方法。