Comments on: Counting occurrences of image colors

By: mano

mano — Fri, 02 Apr 2010 06:47:35 +0000

This the same question as Austin, how find the second largest color, as u said i sorted the color_counts. And after that i did not understand . The permutation index, to re-order the the colors in the unique_colors matrix.

How to do it can u please tell..

Thank You ..

By: Steve

Steve — Mon, 17 Aug 2009 17:25:12 +0000

Arto—Thanks. I fixed it.

By: arto

arto — Wed, 05 Aug 2009 18:52:12 +0000

Hi,code gives error.

 Undefined function or variable "column_data".

Error in ==> count_occ_stev at 84
size(column_data)

Thanks

By: Steve

Steve — Thu, 02 Apr 2009 17:28:20 +0000

Gustavo—All the functions used in this post except for imshow are in MATLAB.

By: Gustavo

Gustavo — Tue, 31 Mar 2009 14:58:30 +0000

I’am a student and this is very intersting to a project that iám working but i have a question this works in MATLAB without the Image Processing Toolbox?

By: Steve

Steve — Thu, 19 Mar 2009 20:01:59 +0000

Austin—Sort the color_counts vector. Use the second output from sort, the permutation index, to re-order the the colors in the unique_colors matrix. Pick off the first three rows.

By: Austin

Austin — Thu, 19 Mar 2009 17:29:46 +0000

Taking this a step further how could you get matlab to count and display not just the maximum occurring color but the top three color occurrences and their locations? Thank you very much for your time.

By: Steve

Steve — Fri, 01 Feb 2008 13:12:15 +0000

Thanks, Urs.

By: Urs (us) Schwarz

Urs (us) Schwarz — Fri, 01 Feb 2008 09:53:14 +0000

two minor comments

- let’s not forget the typical approach

v=10*[1 1 3 5 5 2 3 2 2];
[nc,newix]=histc(v,unique(v));

% which comes with the added bonus of re-indexing the
% values in v in ascending order from 1:#uniques

nc
[v;newix]

- using the option FIRST, unique returns the index to the first rather than the last occurrence (default behavior) of unique values in the second output argument