Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

New to MATLAB?

HISTEQ default not consistent with syntax?

Asked by Jurgen

Jurgen (view profile)

on 15 Nov 2012

If I have an 8-bit image IM (e.g. cameraman.tif), why does histeq(IM) produce a different result than histeq(IM,ones(1,256))??

Shouldn't they be identical? The description says hgram defaults to ones(1,n)*prod(size(A))/n. Since cameraman is 256x256 and n=2^8, shouldn't it scale normally?

0 Comments

Jurgen

Jurgen (view profile)

Tags

Products

No products are associated with this question.

1 Answer

Answer by Matt Fig

Matt Fig (view profile)

on 15 Nov 2012
Accepted answer
IM = imread('cameraman.tif');
I = histeq(IM);
I2 = histeq(IM,ones(1,64)*(numel(IM)/64));
isequal(I,I2)
ans =
       1

1 Comment

Jurgen

Jurgen (view profile)

on 15 Nov 2012

I see it uses n=64 then, I was testing with n=256. Because of the description I was under the impression that n=length(HGRAM). Thanks for clearing that up.

Matt Fig

Matt Fig (view profile)

Contact us