How to make colormaps like the attached colorbar?

Question

Subhodh Sharma 2021-11-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1591314-how-to-make-colormaps-like-the-attached-colorbar

评论： Subhodh Sharma 2021-11-20

采纳的回答： DGM

hello community,

I am quite new to colorbar interpolation techniques. Therefore, I would really appreciate your help in this regards.

I want to make a colormaps like the attached colorbar.

thanks in advance.

2 个评论
显示无隐藏无

DGM 2021-11-20

In what aspects?

Do you want it to be borderless?

Do you want it to be shaped the same?

Do you just want the same colors?

Subhodh Sharma 2021-11-20

@DGM thanks for your response. I want the same color gradient with same colors in the colorbar. only same

colors.

I don't want borderless. I want to make a contour plot. But I can't seem to find any colormap which matches with the above one.

So, I want to make a colormap like the above one with same colors and gradient.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

DGM 2021-11-20

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1591314-how-to-make-colormaps-like-the-attached-colorbar#answer_836194

编辑：DGM 2021-11-20

在 MATLAB Online 中打开

If you just want the colormap used in that image, this is it.

A = imread('colorbarimage.png');

np = 37; % number of points

x0 = 75; % centerline of bar

y0 = 181; % location of first breakpoint

yf = 767; % location of last breakpoint

dy = (yf-y0)/(np-2);

x = x0*ones(1,np);

y = y0-dy/2:dy:y0-dy+np*dy;

imshow(A); hold on; % show image

plot(x,y,'kx','linewidth',2) % and sample locations

% extract a colortable from the image

ct = im2double(squeeze(A(round(y),x0,:)))

ct = 37×3

0.8000 0.4510 0.4510 0.8588 0.4627 0.4627 0.9137 0.4784 0.4784 0.9686 0.4902 0.4902 1.0000 0.5216 0.5020 1.0000 0.5804 0.5020 1.0000 0.6392 0.5020 1.0000 0.6980 0.5020 1.0000 0.7569 0.5020 1.0000 0.8118 0.5020

If you want the colortable to be longer, then you can interpolate.

ctlong = interp1(1:np,ct,linspace(1,np,256))
ctlong = 256×3
8000    0.4510    0.4510
8083    0.4526    0.4526
8166    0.4543    0.4543
8249    0.4560    0.4560
8332    0.4576    0.4576
8415    0.4593    0.4593
8498    0.4609    0.4609
8581    0.4626    0.4626
8659    0.4648    0.4648
8737    0.4670    0.4670