Exporting imshow data into a text file

I used imshow on an image to set up a threshold where the pixels fell below a certain number of counts. And, to see if a new point belongs to one of the sparse regions, I set the (y, x) value to a pixel location (row, column) and then see if the pixel is true or false there at that location.

I would like to convert this pixel data back into the original (y,x) coordinates and put them in a text file so I can associate a position in the image (which is essentially a graph) where the regions are sparse and fall below this threshold.

Answer 1

[Walter Roberson]

http://www.mathworks.com/matlabcentral/fileexchange/29709-function-to-make-a-2d-histogram

then find() where the count is greater than your threshold to get rows and columns. Translate that back to your original coordinates if you want to.

If you divide your range into equal intervals then you can write the 2D histogram easily in terms of accumarray()

[jgillis16]

I have the rows and column, but I am stuck on how to specifically translating it back to the original coordinates (<http://www.mathworks.com/matlabcentral/answers/262923-extracting-information-from-a-plot)>.