sub2ind out of range subscript error

Hi,

I am trying to detect the text in an image using code provided for Automatically Detect and Recognize Text in Natural Images on http://www.mathworks.in/help/vision/examples/automatically-detect-and-recognize-text-in-natural-images.html#zmw57dd0e728.

Getting an error on

ind = sub2ind(size(mserMask), mserRegionsPixels(:,2), mserRegionsPixels(:,1));

Error message is

Attempted to access mserRegionsPixels(:,2); index out of bounds because
size(mserRegionsPixels)=[0,0].

I am using the same image handicapsign.jpg to test this code.

Your prompt response will be highly appreciated.

Thanks

Answer 1

[Image Analyst]

I don't have that toolbox, but backtrack to find out why mserRegionsPixels does not have any coordinates in it. Chances are you replaced the demo image with your image, or you changed a threshold, or something like that.

[Swapnil]

Thanks. It was due to binary image which I was passing as input. When changed to grayImage it worked.

But now new problem is there. As I am new to MATLAB don't know much about nested functions.

Can someone give me exact code for helperGrowEdges and helperStrokeWidth functions used in this example.

[Walter Roberson]

http://www.mathworks.com/help/vision/examples/rmvd_matlablink__fd9658b5212fdf320fa0fb8c69e49f04.html

[Swapnil]

Walter, on this link it gives

edit(fullfile(matlabroot,'toolbox','vision','visiondemos','helperGrowEdges.m'))

If we do this on command line then it creates blank helperGrowEdges.m

What code should be there inside ?

Same way I would like to know the code for helperStrokeWidth.

[Walter Roberson]

If you have the current version of MATLAB with the Computer Vision Toolbox installed, you would get the source. If you do not have the CV toolbox at all or do not have the current version then the demo might not be usable on your version even if you had the source.

[Swapnil]

Walter, I do have Computer Vision System Toolbox Version 5.2(R2013a). But I can't see helperGrowEdges.m and helperStrokeWidth.m at "C:\Program Files\MATLAB\R2013a\toolbox\vision\vision".

Could you please share the code of these two files so that I can create them at that location ?

[Walter Roberson]

R2013a is not the current version; R2014a is the current version. The demo might not be usable for you as it might rely on facilities found only in versions later than what you have.