Ask Your Question

Revision history [back]

click to hide/show revision 1
initial version

questions about cvtypes CV_32S, CV_16F etc.

hello, everyone, I'm new to opencv. While I'm proceeding with opencv tutorials, I have lots of confusions about cvtypes such as CV_32S, and CV_16F. Literally I know the meanings of these types, but I'am not sure about the criteria by which I can make choice to choose one of them in specified situation.

for example, I have encountered a problem when dealing with the tutorial code "imageSegmentaion.cpp" in the part "Image Segmentation with Distance Transofrm and Watershed Algorithm. The problem is showed below:


terminate called after throwing an instance of 'cv::Exception' what(): OpenCV(4.3.0-pre) /home/ehuman/working_cv/opencv-master/modules/highgui/src/precomp.hpp:137: error: (-215:Assertion failed) src_depth != CV_16F && src_depth != CV_32S in function 'convertToShow'

Aborted (core dumped)


Although I can solve the problem by manually changing the type of the image from CV_32S to CV_32F before the function "imshow" according to instructions from website. it's still not clear for me that why I have to do this? In what situation should I use CV_32S? Why there's an assertion described above in function 'convertToShow' ? Could anyone give me some explanations about those types and their usages as well as reasons behind it ? links to specified detailed description are also useful to me. Thank you very much!

questions about cvtypes CV_32S, CV_16F etc.

hello, everyone, I'm new to opencv. While I'm proceeding with opencv tutorials, I have lots of confusions about cvtypes such as CV_32S, and CV_16F. Literally I know the meanings of these types, but I'am not sure about the criteria by which I can make choice to choose one of them in specified situation.

for example, I have encountered a problem when dealing with the tutorial code "imageSegmentaion.cpp" in the part "Image Segmentation with Distance Transofrm and Watershed Algorithm. The problem is showed below:


terminate called after throwing an instance of 'cv::Exception' what(): OpenCV(4.3.0-pre) /home/ehuman/working_cv/opencv-master/modules/highgui/src/precomp.hpp:137: error: (-215:Assertion failed) src_depth != CV_16F && src_depth != CV_32S in function 'convertToShow'

Aborted (core dumped)


Although I can solve the problem by manually changing the type of the image from CV_32S to CV_32F before the function "imshow" according to instructions from website. it's still not clear for me that why I have to do this? In what situation should I use CV_32S? Why there's an assertion described above in function 'convertToShow' ? Could anyone give me some explanations about those types and their usages as well as reasons behind it ? links to specified detailed description are also useful to me. Thank you very much!

questions about cvtypes CV_32S, CV_16F etc.

hello, everyone, I'm new to opencv. While I'm proceeding with opencv tutorials, I have lots of confusions about cvtypes such as CV_32S, and CV_16F. Literally I know the meanings of these types, but I'am not sure about the criteria by which I can make choice to choose one of them in specified situation.

for example, I have encountered a problem when dealing with the tutorial code "imageSegmentaion.cpp" in the part "Image Segmentation with Distance Transofrm and Watershed Algorithm. The problem is showed below:


terminate called after throwing an instance of 'cv::Exception' what(): OpenCV(4.3.0-pre) /home/ehuman/working_cv/opencv-master/modules/highgui/src/precomp.hpp:137: error: (-215:Assertion failed) src_depth != CV_16F && src_depth != CV_32S in function 'convertToShow'

Aborted (core dumped)


Although I can solve the problem by manually changing the type of the image from CV_32S to CV_32F before the function "imshow" according to instructions from website. it's still not clear for me that why I have to do this? In what situation should I use CV_32S? Why there's an assertion described above in function 'convertToShow' ? Could anyone give me some explanations about those types and their usages as well as reasons behind it ? links to specified detailed description are also useful to me. Thank you very much!