changing the histogram color

Is there any way to change the color of a histogram?

Answer 1

[Image Analyst]

If you want each bar in a different color, then try the attached demo (below in blue text).

[evangeline]

thanks

Answer 2

[Bjorn Gustavsson]

Yes.

help hist

There you'll see that hist with no output parameters plot the histogram with BAR, and that you can get the count and bin position out of hist: [N,X] = hist(...

help bar

There you'll find more information about how to control and set the parameters of a bar plot.

So after reading that, and messing about with get(Bh) you'll end up with this:

[N,X] = hist(...
Bh = bar(X,N,'facecolor',[0.3 0.7 0.2]);

HTH

[evangeline]

thanks, could u explain more about the N and X? I have read an image, a=imread(); I displayed it in an axes, and displayed the histogram in a different axes, I want to change that hist's color

[Image Analyst]

That's why I prefer explicit, descriptive variable names. N is the pixel counts, and X is the gray level. You might write this as

axes(handles.axesImage); % Use the image axes to show the image.
imshow(grayImage);
axes(handles.axesPlot); % Use the plot axes for the plot.
[pixelCounts, grayLevels] = imhist(grayImage, 256);
bar(grayLevels, pixelCounts, 'FaceColor', [0.3 0.7 0.2]);

This will give 256 bars with each bar the color [0.3 0.7 0.2] which is greenish.

[evangeline]

thanks, so helpful