Convert 2D image to 3D with color map

Hello,

I have a color image of radiation pattern.

I'd like to convert this image into a 3D image, based on color map (which is coming along with the image).

Example of image that I have.

Please suggest.

[Guillaume]

What do you call a 3D image? And how do you intend to visualise it?

Where is the 3rd dimension encoded if you start with a 2D image?

Answer 1

[Azzi Abdelmalek]

Y = ind2rgb(X,map)

Answer 2

[Image Analyst]

That's an RGB image so it's already 3D.

By 3-D, do you mean a surface, like you'd get from surf()? If so, you'll have to read the colors in your color bar and then create a colormap - a 10 by 3 array of RGB colors. Then you'll have to use rgb2ind() to turn that RGB image into a single valued, monochrome image, at which point you can then use surf to make a 2.5-D perspective rendering where the gray level is like a height above the x-y plane.

[michael]

can you please write some short code for this one so that I'll not get lost?

[Image Analyst]

Make it easy for me by first telling me the coordinates of the rows and columns of the color tiles in your colormap.

[michael]

more or less like in the above picture. Any way, I'm taking only the actual image, without the color codes while presenting it

[Image Analyst]

michael, you're confusing everyone. You're going to have to do a lot better job of explaining very specifically what you want if you want help.

A color image is a 3D image. Other people call a rendering (2-D image on your screen) of a surface (like a 2.5-D surface created by the surf function) a 3-D image.

[Guillaume]

I would not call a colour image a 3D image. Yes, it's a 3D matrix but not a 3D image. A 3D image would consist of voxels and as per my comment to the question, I've no idea how you'd display that (with a VR headset?)

[Image Analyst]

I can agree with that. They're both 3D arrays but they're just interpreted differently. One is interpreted as a color or hyperspectral image while the other is interpreted as a grayscale volumetric image. You could even have a 4D array interpreted as a color volumetric image or as a series of color images (like a video). To view a 3-D monochrome or color volumetric image you'd have to use a different program like Avizo, because MATLAB just isn't set up for that kind of visualization and is limited to primitive cut-away slice views and isosurfaces.

[michael]

I have 2D image which is colored. I'd like to use the color as the 3rd dimension, based on color map.

In the image which was attached, red has a value of 90 and therefore it would be the highest point in the 3rd dimension, then orange, yellow, green and blue which would be nearly 0 in the 3rd dimension.

Hope that it is more clear now.