how to show lab space image

lab color space is (0-100),(-128-127),(-128-127), given an image under lab color space, how to show it suitably (imshow is not appropriate)?

Answer 1

[Ameer Hamza]

What about conversion to RGB before displaying.

imshow(lab2rgb(image));

[xiao]

then does this have any difference with imshow(imread(image)) directly? Is this just the way what lab space look like?

[Ameer Hamza]

If you have a lap space image, then converting it to RGB might result in loss of some information: https://www.mathworks.com/help/images/use-color-space-conversion-to-handle-out-of-gamut-colors.html

Answer 2

[Image Analyst]

You can look at each channel one at a time

subplot(3, 1, 1);
imshow(labImage(:, :, 1), []);
title('L Image', 'FontSize', 20);
subplot(3, 1, 2);
imshow(labImage(:, :, 2), []);
title('A Image', 'FontSize', 20);
subplot(3, 1, 3);
imshow(labImage(:, :, 3), []);
title('B Image', 'FontSize', 20);

[Arthur Fernandes]

That is good but there is anyway to save each subplot to file? That is not using the the save menu option? I'm asking because using any of the following code will write an image that is not using the same mapping in gray scale:

imwrite(labImage(:, :, 3),'imgfile.png');
imwrite(labImage(:, :, 3),gray(100),'imgfile.png');
imwrite(labImage(:, :, 3),gray(256),'imgfile.png');

Nor the following:

imshow(labImage(:, :, 3), []);
cmap = colormap;
imwrite(labImage(:, :, 3),cmap, 'imgfile.png');

[Image Analyst]

If you want a grayscale rendering of the image, not the actual values, you can convert to uint8 and then use a standard format like PNG:

uint8Image = uint8(255 * mat2gray(labImage(:, :, 1)));
imwrite(uint8Image, 'L Channel.PNG');
uint8Image = uint8(255 * mat2gray(labImage(:, :, 2)));
imwrite(uint8Image, 'A Channel.PNG');
uint8Image = uint8(255 * mat2gray(labImage(:, :, 3)));
imwrite(uint8Image, 'B Channel.PNG');

[Arthur Fernandes]

I didn't know about that mat2gray function, I was wandering if Matlab had someting more direct. But still better than using my on code. Thank you!