picture not showing on UIIMageView and buildtime issues

[pikaaboo]

First, well documented book. Thank you. In your first project "coolpig", within the updateImage method, we use MatToUIImage and directly display the generated UIImage in imageView. My imageView is showing a blank white screen. I put a NSLog into the method to check if its working, and its indeed being called every 2 seconds.

Note: I used my own .jpg image and not the default coolPig.png. Also, I didn't build the extra modules. I downloaded the prebuilt framework from opencv.org.

There are also 24 buildtime issues... "Documentation issues" eg: "Not a Doxygen trailing comment" matx.hpp and "Empty paragraph passed to '@param' command" core.hpp

[pikaaboo]

Turns out you can only use the .png image. I can see the UIImageview show the picture now. The documentation issues still persist. I have built your code but they seem to not have these documentation issues. I have about 30 of these issues for project2.

[JoeHowse]

Hi @pikaaboo! Thanks for reading the book and reporting these issues.

I think your project might have the -Wdocumentation compiler flag enabled. This will produce warnings if comments are not in the expected format. I suggest disabling it (or just ignoring the warnings). OpenCV's headers seem to contain some comments that are not fully Doxygen-compliant. It's an issue with OpenCV rather than the book's projects, so you could report it over in the official OpenCV repo (https://github.com/opencv/opencv/issues) if you want to pursue it further.

To disable the -Wdocumentation flag, go to the project's Build Settings pane, find the Apple LLVM 8.0 - Warnings - All Languages section, and set the Documentation Comments option to No.

I will do some tests with JPG images and will respond soon about this.

[pikaaboo]

Thanks for the reply. Disabling the flag removed the warnings. I wasn't sure if these documentation issues were caused by my openCV framework setup since your code did not have any build time warnings (got me a bit concerned). I see that you have done the same with your project file. Thanks for looking into the JPG issue. Also, if it helps, I'm guessing there is a problem while multiplying the origiralMat with randomColor. As a test, I used cv::cvtcolor(originalMat,updatedmat, CV_BGRA2GRAY) and later was able to view the grayscale version of the JPG image in UIImageview. One step that didn't seem to work was cv::multiply.

[JoeHowse]

I'm glad to hear that disabling the flag removed the warnings.

JPGs are working in my tests. Could you attach the file that is not working for you?

[pikaaboo]

Thank you for reviewing. I had re-tested the image with your code and it works. I should have done some mistake while replicating the project. Also, thanks for helping me resolve this problem.