黑色背景从MAT(OPENCV)转换为UIImage后出现

发布于 2025-02-13 00:30:46 字数 3289 浏览 0 评论 0原文

我有一个应用程序,该应用程序使用OPENCV库的某些功能来编辑图像。 将UIImage转换为垫子并将垫子转换为uiimage,我在图像中得到了黑色背景 请告诉我如何修复

我的代码,我用来将uiimage转换为垫子

- (cv::Mat)cvMatFromUIImage:(UIImage *)image
{
    CGColorSpaceRef colorSpace = CGImageGetColorSpace(image.CGImage);
    CGFloat cols = image.size.width;
    CGFloat rows = image.size.height;

cv::Mat cvMat(rows, cols, CV_8UC4); // 8 bits per component, 4 channels (color channels + alpha)

CGContextRef contextRef = CGBitmapContextCreate(cvMat.data,                 // Pointer to  data
                                                cols,                       // Width of bitmap
                                                rows,                       // Height of bitmap
                                                8,                          // Bits per component
                                                cvMat.step[0],              // Bytes per row
                                                colorSpace,                 // Colorspace
                                                kCGImageAlphaNoneSkipLast |
                                                kCGBitmapByteOrderDefault); // Bitmap info flags

CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), image.CGImage);
CGContextRelease(contextRef);

return cvMat;

}

我的代码,我用来将垫子转换为uiimage

-(UIImage *)UIImageFromCVMat:(cv::Mat)cvMat
{
    NSData *data = [NSData dataWithBytes:cvMat.data length:cvMat.elemSize()*cvMat.total()];
    CGColorSpaceRef colorSpace;

if (cvMat.elemSize() == 1) {
    colorSpace = CGColorSpaceCreateDeviceGray();
} else {
    colorSpace = CGColorSpaceCreateDeviceRGB();
}

CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);

// Creating CGImage from cv::Mat
CGImageRef imageRef = CGImageCreate(cvMat.cols,                                 //width
                                    cvMat.rows,                                 //height
                                    8,                                          //bits per component
                                    8 * cvMat.elemSize(),                       //bits per pixel
                                    cvMat.step[0],                            //bytesPerRow
                                    colorSpace,                                 //colorspace
                                    kCGImageAlphaNone|kCGBitmapByteOrderDefault,// bitmap info
                                    provider,                                   //CGDataProviderRef
                                    NULL,                                       //decode
                                    false,                                      //should interpolate
                                    kCGRenderingIntentDefault                   //intent
                                    );


// Getting UIImage from CGImage
UIImage *finalImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);

return finalImage;

}

我的代码的示例

-(UIImage *)stroked:(UIImage *)image color:(int)color strock:(float)strock {
cv::Mat img = [self cvMatFromUIImage:image];

return [self UIImageFromCVMat:img];

}

I have an application that uses some functions of the OpenCV library to edit images.
After converting UIImage to Mat and Mat to UIImage I get a black background in the image
please tell me how to fix it

my code which i use to convert UIImage to Mat

- (cv::Mat)cvMatFromUIImage:(UIImage *)image
{
    CGColorSpaceRef colorSpace = CGImageGetColorSpace(image.CGImage);
    CGFloat cols = image.size.width;
    CGFloat rows = image.size.height;

cv::Mat cvMat(rows, cols, CV_8UC4); // 8 bits per component, 4 channels (color channels + alpha)

CGContextRef contextRef = CGBitmapContextCreate(cvMat.data,                 // Pointer to  data
                                                cols,                       // Width of bitmap
                                                rows,                       // Height of bitmap
                                                8,                          // Bits per component
                                                cvMat.step[0],              // Bytes per row
                                                colorSpace,                 // Colorspace
                                                kCGImageAlphaNoneSkipLast |
                                                kCGBitmapByteOrderDefault); // Bitmap info flags

CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), image.CGImage);
CGContextRelease(contextRef);

return cvMat;

}

my code which i use to convert Mat to UIImage

-(UIImage *)UIImageFromCVMat:(cv::Mat)cvMat
{
    NSData *data = [NSData dataWithBytes:cvMat.data length:cvMat.elemSize()*cvMat.total()];
    CGColorSpaceRef colorSpace;

if (cvMat.elemSize() == 1) {
    colorSpace = CGColorSpaceCreateDeviceGray();
} else {
    colorSpace = CGColorSpaceCreateDeviceRGB();
}

CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);

// Creating CGImage from cv::Mat
CGImageRef imageRef = CGImageCreate(cvMat.cols,                                 //width
                                    cvMat.rows,                                 //height
                                    8,                                          //bits per component
                                    8 * cvMat.elemSize(),                       //bits per pixel
                                    cvMat.step[0],                            //bytesPerRow
                                    colorSpace,                                 //colorspace
                                    kCGImageAlphaNone|kCGBitmapByteOrderDefault,// bitmap info
                                    provider,                                   //CGDataProviderRef
                                    NULL,                                       //decode
                                    false,                                      //should interpolate
                                    kCGRenderingIntentDefault                   //intent
                                    );


// Getting UIImage from CGImage
UIImage *finalImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);

return finalImage;

}

example of my code

-(UIImage *)stroked:(UIImage *)image color:(int)color strock:(float)strock {
cv::Mat img = [self cvMatFromUIImage:image];

return [self UIImageFromCVMat:img];

}

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十年不长 2025-02-20 00:30:46

功能功能,无生殖问题。
由于提示,我调整了kcgimagealphanoneskiplast | kcgbitmapbyteorderdefault至kcgbitmapbyteorder32big | kcgimagealphapremultiplipiedlast

kcgimagealphanone | kcgbitmapbyteorderdefault to
kcgbitmapbyteorderdefault | kcgimagealphapremultiplelast

Functionally functional, no reproduction issues.
Because of a hint, I adjusted kCGImageAlphaNoneSkipLast|kCGBitmapByteOrderDefault to kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast

kCGImageAlphaNone|kCGBitmapByteOrderDefault to
kCGBitmapByteOrderDefault | kCGImageAlphaPremultipliedLast

~没有更多了~
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