How can I convert a ROS Image topic into an matrix that I can process in Simulink?

Antti - 2023-05-18T10:02:10+00:00

Question: How can I convert a ROS Image topic into an matrix that I can process in Simulink?

I am trying to find a simple way of converting images received from ROS into matrix form that can then be processed in Simulink. On Matlab side there are the writeImage and readImage functions that can be used to convert ROS Image to matlab image but I am not sure what should be the correct way of doing this on Simulink side. One option would be to get the raw data from Image topic and reorganize it into matrix form, but that processing is always dependent on the image size and format. Is there any simple way of doing this?

Related Questions

Expert Answer

Prashant Kumar answered . 2025-11-20

function img = fcn(msg)
%#codegen

%Get msg details
imgData = msg.Data;
imgH = msg.Height;
imgW = msg.Width;

%Create blank image output with required size
img = zeros(msg.Width,msg.Height,3);

%Reshape image data
imgR = reshape(imgData(1:3:end),imgW,imgH)';
imgG = reshape(imgData(2:3:end),imgW,imgH)';
imgB = reshape(imgData(3:3:end),imgW,imgH)';
img(:,:,1) = imgR;
img(:,:,2) = imgG;
img(:,:,3) = imgB;

Note that this example assumes image is in the RGB color space.

Not satisfied with the answer ?? ASK NOW