필터 지우기
필터 지우기

Save pixel color value for indexed image (without image Processing Toolobx)

조회 수: 1 (최근 30일)
With reference to Steve Eddins blog post on pixel colors: http://blogs.mathworks.com/steve/2006/02/10/all-about-pixel-colors-part-3/
Suppose I create his same image: A = magic(5);
Then I display it with imagesc and colormap HSV: imagesc(A); colormap(hsv);
Is there any way now (without using Image processing Toolbox) to save to a matrix the R,G,B triplets corresponding to the colors of each pixel as produced using HSV?
Thanks, Matteo
  댓글 수: 1
Matteo Niccoli
Matteo Niccoli 2012년 2월 8일
Thanks Walter and Sean.
It will take me some time but i will try both suggestions and then will comment on results.
Matteo

댓글을 달려면 로그인하십시오.

채택된 답변

Walter Roberson
Walter Roberson 2012년 2월 8일
apply that routine and then get() the CData property and that will be the RGB.
  댓글 수: 6
Matteo Niccoli
Matteo Niccoli 2012년 3월 12일
Sorry, it took me a bit to get back to this.
The example in my original question was a simple one, and with a reference to Steve's blog, so it was perfect to explain what I wanted to do (I often tent to be a bit vague, typical of non native speakers).
Sean, usually my images would have more than 256 elements, so I will have to look into the suggested method more carefully as I'm not familiar with either histc or numel.
With one of the maps I had in mind I was trying to get to the RGB colors after the application of an overlay with alpha as in this other post by Steve: http://blogs.mathworks.com/steve/2009/02/18/image-overlay-using-transparency/ . Walter's idea of using freezeColors worked in that case too, with a slight adaptation. I'm about to post an example on my blog and I will acknowledge the answer, then post it on this thread.
Matteo Niccoli
Matteo Niccoli 2012년 4월 9일
Hi Walter
Here's my blog post showing what I am doing (I used your suggestion and applied to color with shading)
http://mycarta.wordpress.com/2012/04/05/visualization-tips-for-geoscientists-matlab-part-ii/
Thanks again. And thanks to Sean as well.
Matteo

댓글을 달려면 로그인하십시오.

추가 답변 (1개)

Sean de Wolski
Sean de Wolski 2012년 2월 8일
Something like:
A = magic(5);
imagesc(A);
map = hsv;
colormap(map);
Av = A(:);
[~, bin] = histc(Av,linspace(min(Av),max(Av),min(numel(Av),size(map,1))));
mapp = permute(map,[1 3 2]);
rgb = reshape(mapp(bin,:,:),size(A,1),size(A,2),3);
maybe?
  댓글 수: 3
Sean de Wolski
Sean de Wolski 2012년 2월 9일
You missed a closing ')' on that line - just like the error message says.
Just copy and paste it.
Matteo Niccoli
Matteo Niccoli 2012년 3월 12일
I'll check it out, thank you Sean.

댓글을 달려면 로그인하십시오.

카테고리

Help CenterFile Exchange에서 Images에 대해 자세히 알아보기

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by