Does exist something like cvShowImage for iOS? - iphone

Question

I'm processing images (using AVFoundation and OpenCV on iOS) and I want to simply display contents of CMSampleBufferRef (or IplImage) to screen.
Simply: I just want to display (like with OpenCV's cvShowImage()) non-converted image to see if I'm not dealing with corrupted or somehow deformed image.

Answer 1

Sadly not. Different bitmap representation.
Perhaps you want a category? I use something along the lines of this:
// NSImage+OpenCV.h
#interface NSImage (OpenCV)
+ (NSImage*)imageWithCVMat:(const cv::Mat&)cvMat;
- (id)initWithCVMat:(const cv::Mat&)cvMat;
- (cv::Ptr<cv::Mat>)cvMat;
#end
// NSImage+OpenCV.m
using namespace cv;
#implementation NSImage (OpenCV)
- (id)initWithCVMat:(const cv::Mat&)cvMat {
NSData *data = [NSData dataWithBytes:cvMat.data
length:cvMat.total()*cvMat.elemSize()];
CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
CGColorSpaceRef colourSpace = CGColorSpaceCreateDeviceRGB();
CGImageRef imageRef = CGImageCreate(cvMat.cols,
cvMat.rows,
8,
8 * cvMat.elemSize(),
cvMat.step[0],
colourSpace,
kCGImageAlphaNone |
kCGBitmapByteOrderDefault,
provider,
NULL,
false,
kCGRenderingIntentDefault);
NSImage *image = [[NSImage alloc] initWithCGImage:imageRef size:CGSizeMake(cvMat.cols,cvMat.rows)];
CGColorSpaceRelease(colourSpace);
CGDataProviderRelease(provider);
CGImageRelease(imageRef);
return image;
}
+(NSImage*)imageWithCVMat:(const cv::Mat&)cvMat {
return [[NSImage alloc] initWithCVMat:cvMat];
}
- (cv::Ptr<cv::Mat>)cvMat {
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)[self TIFFRepresentation], NULL);
CGImageRef imageRef = CGImageSourceCreateImageAtIndex(source, 0, NULL);
cv::Ptr<cv::Mat> cvMat = new cv::Mat(self.size.height, self.size.width, CV_8UC4);
CGContextRef contextRef = CGBitmapContextCreate(cvMat->data,
cvMat->cols,
cvMat->rows,
8,
cvMat->step[0],
CGImageGetColorSpace(imageRef),
kCGImageAlphaNoneSkipLast |
kCGBitmapByteOrderDefault);
CGContextDrawImage(contextRef,
CGRectMake(0, 0, cvMat->cols, cvMat->rows),
imageRef);
CGContextRelease(contextRef);
CGImageRelease(imageRef);
return cvMat;
}
#end