从 MATLAB 中的 2D 地图绘制体积 3D 数据? [英] Volumetric 3D data plotting from 2D map in MATLAB?

问题描述

我有一张热图

并希望将此 2D 矩阵转换为 3D 体积/形状/表面数据点以进行进一步处理.不是简单地使用 surf 以 3D 形式显示它.

and want to convert this 2D matrix to a 3D volume/shape/surface data points for further processing. Not simply display it in 3D using surf.

这样做的好方法是什么?

What would be a good way to do this?

在这个社区的大力帮助下，我可以走得更近:

With a lot of help from this community I could come closer:

为简单起见，我将尺寸缩小到 45x45 像素.

I shrunk the size to 45x45 px for simplicity.

I = (imread("TESTGREYPLASTIC.bmp"))./2+125;
Iinv = 255-(imread("TESTGREYPLASTIC.bmp"))./2-80;%

for i = 1:45
for j = 1:45
A(i, j, I(i,j) ) = 1;
A(i, j, Iinv(i,j) ) = 1;
end
end
volshow(A)

它并不理想，但矩阵正是我现在想要的.也许可以改进循环以在处理 1200x1200 点时运行得更快.

Its not ideal but the matrix is what I wanted now. Maybe the loop can be improved to run faster when dealing with 1200x1200 points.

我现在如何创建一个真正的封闭曲面?

How do I create a real closed surface now?

推荐答案

在与 @BoilermakerRV 对话后，我猜您正在寻找以下两个结果之一:

Following your conversation with @BoilermakerRV, I guess you are looking for one of the following two results:

1. 3d 点的列表，其中 x 和 y 是图像中像素的索引，z 是对应像素的值.结果将是一个 m*n by 3 矩阵.

一个 m x n x 256 零和一的体积，对于图像中的 (i,j)-th 像素，(i, j)-the除了I(i, j).

An m by n by 256 volume of zeros and ones, that for (i,j)-th pixel in the image, all voxels of the (i, j)-the pile of the volume are 0, except the one at I(i, j).

看看下面生成两个结果的例子:

Take a look at the following example that generates both results:

    close all; clc; clear variables;
    I = rgb2gray(imread('data2.png'));
    imshow(I), title('Data as image') 

    % generating mesh grid
    [m, n] = size(I);
    [X, Y] = meshgrid(1:n, 1:m);

    % converting image to list of 3-d points
    P = [Y(:), X(:), I(:)];
    figure 
    scatter3(P(:, 1), P(:, 2), P(:, 3), 3, P(:, 3), '.')
    colormap jet
    title('Same data as a list of points in R^3')

    % converting image to 256 layers of voxels
    ind = sub2ind([m n 256], Y(:), X(:), I(:));
    V = zeros(m, n, 256);
    V(ind) = 1.0;
    figure
    h = slice(V, [250], [250], [71]) ;
    [h.EdgeColor] = deal('none');
    colormap winter
    camlight
    title('And finally, as a matrix of 0/1 voxels')

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