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iosopencvuiimageobjective-c++flood-fill

iOS opencv floodfill Error


I'm trying to port my C++ opencv App to iOs, but I'm always getting this error :

OpenCV Error: Unsupported format or combination of formats () in cvFloodFill, file /Users/user/slave/ios_framework/src/opencv/modules/imgproc/src/floodfill.cpp, line 618
libc++abi.dylib: terminate called throwing an exception

Here's my code :

- (cv::MatND)calc_Hist
{

    using namespace cv;
    UIImage *temp = [UIImage imageNamed:@"file.png"];
    Mat src = [self cvMatFromUIImage:temp];
    Mat hsv;
    Mat mask;
    MatND hist;
    int lo = 151; int up = 170;
    cv::Point seed = cv::Point( 1029, 270 );
    int newMaskVal = 255;
    Scalar newVal = Scalar( 120, 120, 120 );
    int connectivity = 8;

    int h_bins = 30; int s_bins = 32;
    int histSize[] = { h_bins, s_bins };
    float h_range[] = { 0, 179 };
    float s_range[] = { 0, 255 };
    const float* ranges[] = { h_range, s_range };
    int channels[] = { 0, 1 };

    cvtColor(src, hsv, CV_BGR2HSV);
    int flags = connectivity + (newMaskVal << 8 ) + cv::FLOODFILL_FIXED_RANGE + cv::FLOODFILL_MASK_ONLY;
    cv::Mat mask2 = cv::Mat::zeros( src.rows + 2, src.cols + 2, CV_8UC1 );

    UIImage *imgs = [self UIImageFromCVMat:hsv];
    [_viewer setImage:imgs];

    floodFill( src, mask2, seed, newVal, 0, cv::Scalar( lo, lo, lo ), cv::Scalar( up, up, up), flags );

    mask = mask2( cv::Range( 1, mask2.rows - 1 ), cv::Range( 1, mask2.cols - 1 ) );
    calcHist( &hsv, 1, channels, mask, hist, 2, histSize, ranges, true, false );
    normalize( hist, hist, 0, 255, cv::NORM_MINMAX, -1, cv::Mat() );
    return hist;

}

This function works fine on my Mac, so I first thought the image is not converted properly, but it shows the image if I display it in a UIImageView.

Here's the conversion method

- (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

    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);
    CGColorSpaceRelease(colorSpace);

    return cvMat;
}

Is the iOS framework reduced in any way compared to the "normal" one? I searched with google but I didn't find anything to solve my problem.


Solution

  • The error occurs when a function encounters a type of matrix that the function cannot handle. Examine type of the input matrix for floodFill with src.type(). According to OpenCV manual

    image – Input/output 1- or 3-channel, 8-bit or floating-point image. It is modified by the function unless the FLOODFILL_MASK_ONLY flag is set (in the second variant of the function; see below)