Nerian Support Forum

hello,

i'm trying to get color disparity map not NVCom but C++ code.

when i use a function 'writePgmFile()', i see '.pgm' images with gray-color.

and a result mat of 'toOpenCVImage()' function is 2-depth.

would you plz give directions to save color disparity map?

thanks.

If you are trying to replicate the color coding of NVCom, you can download the full source code from our download page. The relevant class is in the files:
nerian-vision-software-9_0_5-src/nvcom/helpers/colcoder.*

This class applies color coding to an OpenCV image, which you can get from the toOpenCVImage() method.

OpenCV itself also provides a similar functionality. Please have a look at this article:
https://docs.opencv.org/4.x/d3/d50/group__imgproc__colormap.html

thanks for quick reply. it is very helpful.

Hello,
is there a way to use the functionality of nvcom/helpers/colorcoder.cpp with Python? More precisely, I would like to know how to apply colormap_rainbow to disparity map with Python just like in the API review page (which uses for example rainbow color map and sets invalid pixels to gray). I tried with cv2.applyColorMap() but it does not set the invalid pixels to gray like in the API.

For the ColorCoder class there is unfortunately no python binding. Given the small size of this class, the best option would be to re-create this class in python. All it does is, it linearly interpolates between the colors in the color table.

There are some optimizations being done, like pre-computing all the colors for 8-bit and 16-bit images, but these optimizations are not necessary if performance is not super critical.