UMAT refcount error with setUseOpenCL(false)

asked 2017-04-26 03:36:47 -0500

theaniolad gravatar image

updated 2017-04-26 10:44:27 -0500

Currently I'm rewritting some code from Mat to UMat that will hopefully run both with or without OpenCL depending on the OpenCL flag. Now I'm getting a refcount error I don't quite understand. It only shows up if setUseOpenCL is set to false.

(Since the images I work with are around 196Megapixel-RGB-images I do prefer avoiding deep copies as much as possible and I would like to understand why in the code below I'm not allowed to write into the orginal UMat.)

By the way: is there an easy way to simply convert any image (gray, bgr, bgra) to gray or even directly to CV_32FC1 or do I always have to manually check if the image is bgra or bgr or gray and then do a conversion?


main()
{
   ocl::setUseOpenCL(false); //myFoo() crashes only if this is set to false.
  myFoo(myimg, outImg);
}

//in this function the line convertTo() crashes if the input UMat is the same as the output UMat and setUseOpenCL is set to false void myFoo(InputArray img_ext, OutputArray img_Out) { UMat gray; //if I use Mat instead of UMat it doesnt crash. img_ext.copyTo(gray); //I also tried using getUMat(), but in both cases convertTo() below crashes.

cvtColor(gray, gray, COLOR_BGR2GRAY); //doesn't crash

UMat gray2; gray.convertTo(gray2, CV_32FC1); //this doesnt crash

gray.convertTo(gray, CV_32FC1); //crashes with error message: OpenCV Error: Assertion failed (u->refcount == 0) in cv::StdMatAllocator::deallocate

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Comments

img_ext.copyTo(gray); --> You are using a CPU function to copy data from CPU memory into GPU memory. Afaik, this is impossible...

StevenPuttemans gravatar imageStevenPuttemans ( 2017-04-26 07:21:47 -0500 )edit

Thank you for your response! The error occurs when I set OpenCL to false which - as far as I understand - will make OpenCV call the Mat functions internally so that CopyTo() should be a pure CPU to CPU copy with no GPU involved. If I set OpenCL to true and use the GPU, the whole code works fine. The copying and all lines below work fine except for the convertTo() line.

theaniolad gravatar imagetheaniolad ( 2017-04-26 11:00:09 -0500 )edit