colors detection and display them

How can i reduce number of colors in image (to 32 colors ) and display colors used in the picture in form one column ?

Answer 1

[Walter Roberson]

[newimage, newmap] = rgb2ind(existingimage, 32);

But it is not clear in your question whether you just want to display the unique colors (if so then display newmap) or if you want to display the indices (if so then display newimage).

I am also not sure what order you want to display the output in. The indices would be a two dimensional array, one index per pixel. You could reshape() that as a column, but will the user understand? The colormap would be an array with three columns (R, G, B), and displaying in one column does not strike me as being a good thing ?

[safa]

actually, i want to do what is done in website in following website http://www.picstoknits.co.uk/ user can select picture and at the end ,out put is a colorbar, showing all colors used in picture.

anyway thank you for answer