RGB to Lab color space

Question

Ivana 2016-12-6

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/315624-rgb-to-lab-color-space

评论： Ivana 2016-12-7

I want to converte RGB values to Lab, I read that conversion goes between XYZ color space. Ofcourse, I find directly alghorithm in Matlab

labTransformation = makecform('srgb2lab');

labI = applycform(image,labTransformation);

l = labI(:,:,1);

a = labI(:,:,2);

b = labI(:,:,3);

but it shows me values between 0-255 and I need standard values for Lab, L=0-100, a,b=-127+128. Because later I want calculate C and H with a, b values.

Thanks.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Adam 2016-12-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/315624-rgb-to-lab-color-space#answer_246156

在 MATLAB Online 中打开

Just using

lab = rgb2lab(rgb);

seems to give results in the expected output range. I'm not sure what all the extra work of creating a colour transform gives you, even if it did give the answer you want.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Ivana 2016-12-7

Thanks, I also found this conversion when I get Lab in uint 8 (0-255) to convert to Lab standard range values: L=L/2,55; a=a-127; b=b-128. I chek this and it realy works, now I will update my algorithm.

请先登录，再进行评论。