New to Matlab, Trying to superimpose histograms!

Hi! I have been using the 'impixel' command to develop 10 5x5 samples of a greyscale image. Using these samples I have tried to create histograms using the 'imhist' function. But I am stuck on how to superimpose the 10 histograms I have created into one histogram.

I've tried to define the histograms as variables and then using the plot function, however this isn't working. Nor is using imhist(Matrix1,Matrix2...Matrix10).

Basically my question is, How can I superimpose histograms?

Answer 1

[dpb]

Don't have Image Processing Toolbox here so can't use imhist directly, but I'd presume like regular hist and/or bar you can use it the first time to generate the plot and then

hold on

Oh, looking at the online doc, imhist is another of those aberrations that doesn't support an axes handle as an input so it looks like it will create a new figure irregardless.

As the later example there shows, generate the counts w/ imhist and then use stem to plot them. Again, the first will be a new figure, then

hold on

followed by a loop for each subsequent figure. Or, build and array of counts by column and a single call to stem will do them all at once.

doc stem

for the details on it.

Answer 2

[Image Analyst]

If you want to superimpose lots of histograms, I think the best option is to use plot(counts, 'Color', [r,g,b]) rather than bar().