MATLAB: Simulation Map Generator issues

line followingmobile robotics training toolboxroboticssimulation mapsimulink

Has anyone managed to successfully run the Simulation Map Generator app in the Mobile Robotics Training Toolbox? I loaded a png file (tried a jpg, that didn't work either), and the track size. When I select "Map Options/Line Follower", I get the error messages listed below in the main Matlab window. I get the same messages when I switch from Automatic to Manual Threshold mode. 
Error using rgb2gray>parse_inputs (line 80) 
MAP must be a m x 3 array. 
Error in rgb2gray (line 52) 
isRGB = parse_inputs(X); 
Error in simMapGenerator/thresholdMap (line 47) 
imgGray = rgb2gray(imgRaw); 
Error in simMapGenerator/thresholdOptionsSelect (line 394) 
app.thresholdMap; 
Error using matlab.ui.control.internal.model.AbstractMutualExclusiveComponent/set.Value (line 166) 
Error while evaluating ButtonGroup SelectionChangedFcn.

Best Answer

The error you linked is a common one that happens when you input a grayscale (M x N) image instead of a color (M x N x 3) image.
Seems like the toolbox assumes all images passed in as color images and tries to use the rgb2gray function regardless of whether the image is already grayscale!
So you have 2 options:
  • Short-term fix: Save your images as color images and try again
  • Long-term fix: Add logic to the app to handle this.
To fix the code with the long-term fix, here are the steps:
  1. Open the app ( edit simMapGenerator.mlapp )
  2. Go to the "Code View" section
  3. In line 47, you will see the code imgGray = rgb2gray(imgRaw); Change it to this:
if size(imgRaw,3) == 1
    imgGray = imgRaw;
else
    imgGray = rgb2gray(imgRaw);
end
Hope that helps!
- Sebastian
Related Question