How can I change the line color in the output of imhist?

imhist provides the output in blue lines;i want to change it into say either red or green

Answer 1

[Image Analyst]

For precise control, plot it yourself with bar() and then set the 'EdgeColor' and 'FaceColor' properties in the bar() function:

img = imread('moon.tif');
[counts, grayLevels] = imhist(img, 64);
bar(grayLevels, counts, 'EdgeColor', 'r', 'FaceColor', 'c', 'BarWidth', 0.95);

Makes cyan bars with red outlines.

[Suresh Kumar]

This works fine. But is it possible to change the colour in original imhist output without the use of 'bar'..

[Image Analyst]

imhist() does not allow any inputs that will vary the color of the lines.

[Suresh Kumar]

okay,thanks a lot

[Baptiste Ottino]

Suresh, I gave you a way as an answer, by using findobj.

[Suresh Kumar]

But the output I am getting for findobj() is a zero matrix.. >> myhist=findobj(gca,'Type','Stem')

myhist =

   Empty matrix: 0-by-1

[Image Analyst]

This worked for me:

img = imread('moon.tif');
imhist(img, 64);
 myHist = findobj(gca, 'Type', 'Stem');
 % Change the color to red
 myHist.Color = [1 0 0]

but Suresh was wondering if it could all be done inside imhist() without a separate call to bar(), or to findobj() and myHist.Color.

Personally, I like the wider bars created by bar() rather than the single pixel wide lines by imhist's build in stem display.

Answer 2

[Baptiste Ottino]

The histogram is a 'Stem' element. Use findobj to access its properties:

 imhist(myImage);
 myHist = findobj(gca, 'Type', 'Stem');

 % Change the color to red
 myHist.Color = [1 0 0]

If you use an older version of Matlab, you can replace the last line by:

 % Change the color to red
 set(myHist, 'Color', [1 0 0]);

Good luck!