MATLAB: Indexed Images for Cielab Color Space

cielabcolor spaceImage Processing Toolboxindexed images

Hi!

How can I build a function indexed image for other color spaces such as CIELAB? any help..?

Best Answer

I'm not sure what that means. You can convert a color RGB image into hsv with rgb2hsv()

hsvImage = rgb2hsv(rgbImage);

and into lab with makecform():

cform = makecform('srgb2lab');
labImage = applycform(rgbImage,cform);

Creating an indexed image doesn't make any sense. You'd have to create a grayscale image and then use the proper colormap, but why? Like my demo shows, you can create RGB images that are better.

See my attached demo.

Related Solutions

MATLAB: Getting RGB from image created with imagesc

You probably want ind2rgb. But if you're using imagesc, rather than image, you're probably need to scale your color values. It looks something like this:

v = ??; % my matrix
map = colormap;
minv = min(v(:));
maxv = max(v(:));
ncol = size(map,1);
s = round(1+(ncol-1)*(v-minv)/(maxv-minv));
rgb_image = ind2rgb(s,map);

If you have integer color values, then you don't need to do that scaling before calling ind2rgb.

MATLAB: How to convert the RGB color map into an HSV color map

No that does not make any sense. You can't just apply some different colormap to an indexed image and expect it to look sensible. It will look like garbage. And calculating the variance of a colormap is meaningless. Perhaps you want the color frequency image like this calculates but I don't know.

I think perhaps you're getting color map confused with colorspace. You want to do something, though I don't know what it is. And you think that this colormap approach is the way to do it, but it's not - it's a dead end. So why don't you tell me what you really want to do and I can recommend an approach. For example you want so segment out pixels of some particular color out of an image, or you want to classify the image into 5 different color classes.

Best Answer

Related Solutions

MATLAB: Getting RGB from image created with imagesc

MATLAB: How to convert the RGB color map into an HSV color map

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