MATLAB点云处理：点云赋色 | 显示自定义颜色的点云

Posted 2021-08-13 借我十斤肉

文章目录

• • 1 区别
  • 2 点云赋色
  • 3 显示自定义颜色的点云

1 区别

点云赋色改变的是点的Color属性，是质的改变。

显示自定义颜色的点云没有改变点云的Color属性，仅仅是表现形式。

2 点云赋色

直接上代码

clc;
clear;
ptCloud = pcread('treeXYZRGB.pcd');
figure;
pcshow(ptCloud);                    % 显示原始点云
title('原始点云');
hold on;
ptCloud                           % 打印原始点云ptCloud详情

xyzpoints = ptCloud.Location;       % 将点云的位置信息赋给xyzpoints
ptCloudXYZ = pointCloud(xyzpoints);
figure;
pcshow(ptCloudXYZ);                 %显示只有位置信息的点云，MATLAB会按高程进行渲染
title('只有位置信息的点云');
hold on;
ptCloudXYZ                           % 打印ptCloudXYZ详情

% 点云赋色
cmatrix = ones(size(ptCloudXYZ.Location)).*[1 0 1];
ptCloudXYZRGB = pointCloud(xyzpoints,'Color',cmatrix);

figure;
pcshow(ptCloudXYZRGB); %显示赋色后的点云
title('赋色后的点云');
hold off;
ptCloudXYZRGB                          % 打印ptCloudXYZRGB详情

显示结果：

注意： 当点云没有颜色信息时，pcshow()函数会对点云按高程进行渲染显示，但并不会为点云赋上颜色信息，Color为空[]，仅限于表现形式。可以从下面的输出结果中验证。

打印输出结果：

ptCloud = 

  pointCloud - 属性:

     Location: [5746×3 single]
        Color: [5746×3 uint8]
       Normal: []
    Intensity: [5746×1 single]
        Count: 5746
      XLimits: [64.7470 67.8900]
      YLimits: [-54.1659 -50.9061]
      ZLimits: [-20.1166 -13.2595]


ptCloudXYZ = 

  pointCloud - 属性:

     Location: [5746×3 single]
        Color: []
       Normal: []
    Intensity: []
        Count: 5746
      XLimits: [64.7470 67.8900]
      YLimits: [-54.1659 -50.9061]
      ZLimits: [-20.1166 -13.2595]


ptCloudXYZRGB = 

  pointCloud - 属性:

     Location: [5746×3 single]
        Color: [5746×3 uint8]
       Normal: []
    Intensity: []
        Count: 5746
      XLimits: [64.7470 67.8900]
      YLimits: [-54.1659 -50.9061]
      ZLimits: [-20.1166 -13.2595]

3 显示自定义颜色的点云

这个更简单

clc;
clear;
ptCloud = pcread('treeXYZ.pcd');    % 从输入点坐标创建点云对象
figure;
pcshow(ptCloud);                    % 显示原始点云
title('原始点云');
hold on;
ptCloud                           % 打印原始点云详情

figure;
pcshow(ptCloud.Location,[1,0,1]); % 显示自定义颜色的点云
title('显示自定义颜色的点云');
hold off;
ptCloud                           % 再次打印ptCloud详情

显示结果：

尽管在外观上，与点云赋色的效果一致，但本质上颜色字段依然为空[]，可以从下面的输出结果中验证.

打印输出结果：

ptCloud = 

  pointCloud - 属性:

     Location: [5746×3 single]
        Color: []
       Normal: []
    Intensity: []
        Count: 5746
      XLimits: [64.7470 67.8900]
      YLimits: [-54.1659 -50.9061]
      ZLimits: [-20.1166 -13.2595]


ptCloud = 

  pointCloud - 属性:

     Location: [5746×3 single]
        Color: []
       Normal: []
    Intensity: []
        Count: 5746
      XLimits: [64.7470 67.8900]
      YLimits: [-54.1659 -50.9061]
      ZLimits: [-20.1166 -13.2595]