Increasing number of interpolating color in patch

Hi all,

I have created a patch with the color varying between two random colors. However, I would like to increase the number of interpolating colors.

Here we can see the shading are quite obvious.

Could you please help

x = [0 1 1 0];
y = [0 0 1 1];
c1 = [0.55 0.95 0.35];
c2 = [.65 .75 .55];
cdata(1,1,:) = c2;
cdata(1,2,:) = c2;
cdata(1,3,:) = c1;
cdata(1,4,:) = c1;

p =patch(x,y,'k');

set(p,'CData',cdata, ...
    'FaceColor','interp', ...
    'EdgeColor','none');

[Walter Roberson]

It looks pretty smooth to me on my system. I do not see any boundaries.

[Shan Chu]

Hi,

The green one was okay but if I change to other color which are close in the colormap. For example, two grays like the fig below. You can clearly see the shading

[Walter Roberson]

I have to look hard to see any banding; I can only tell when I scroll the image up and down so that perceptual moving edge detectors kick in.

[Shan Chu]

Anyway sir, Do you have the solution for this :D

[Walter Roberson]

I have yet to see a problem.

[David Wilson]

I agree, the banding problem is quie subtle, and could well be an issue with your monitor.

One option is to subdivide your patch into say quadrants, and then interpolate the RGB values accordingly, and then plot all 4 as 4 separate patches. I'm assuming that will double the effective resolution & therefore reduce the banding.

[Walter Roberson]

When I look at the grayscale picture on my smartphone, then I can just barely see a band near the top, and only by scrolling back and forth. I might see a second band, but it is down in the level where it could be the power of suggestion. When I look at the grayscale picture on my iMac 27", I cannot reliably see any banding.

I also tried with using [0 0 0] [1 0 0] [0 1 0] [0 0 1] in the four corners. I could not see any banding at all.