MATLAB全景图切割及盒图显示怎么实现

小编给大家分享一下MATLAB全景图切割及盒图显示怎么实现，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！

part1 全景图切割

原图：

切割效果：

以下是切割部分步骤：
举这张图为例，图片格式hdr,jpg啥的都行：

1.1 边缘剔除

有些全景图会自带白灰色边缘，若是直接进行切割便会出现如下效果：

这时候我们首先要对原图进行白边剔除，代码如下：

oriPic=imread('test.hdr');[rows,cols,~]=size(oriPic);for i=cols:-1:1    tempListR=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    tempListG=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    tempListB=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    if all(round(tempListR-mean(tempListR))==0)&&all(tempListR==tempListG)&&all(tempListR==tempListB)        oriPic(:,i,:)=[];    else        break;    endendoriPic=oriPic(:,end:-1:1,:);for i=size(oriPic,2):-1:1    tempListR=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    tempListG=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    tempListB=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    if all(round(tempListR-mean(tempListR))==0)&&all(tempListR==tempListG)&&all(tempListR==tempListB)        oriPic(:,i,:)=[];    else        break;    endendoriPic=oriPic(:,end:-1:1,:);for i=rows:-1:1    tempListR=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    tempListG=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    tempListB=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    if all(round(tempListR-mean(tempListR))==0)&&all(tempListR==tempListG)&&all(tempListR==tempListB)        oriPic(i,:,:)=[];    else        break;    endendoriPic=oriPic(end:-1:1,:,:);for i=size(oriPic,1):-1:1    tempListR=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    tempListG=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    tempListB=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    if all(round(tempListR-mean(tempListR))==0)&&all(tempListR==tempListG)&&all(tempListR==tempListB)        oriPic(i,:,:)=[];    else        break;    endendoriPic=oriPic(end:-1:1,:,:);

1.2 图像裁剪

我们要让完成的就是如下的变换和裁剪：

这部分其实已经有较为成熟的原理和代码：
代码参考：https://stackoverflow.com/questions/29678510/convert-21-equirectangular-panorama-to-cube-map

原理参考：
http://paulbourke.net/panorama/cubemaps/#1

http://paulbourke.net/panorama/cubemaps/

原理参考文章中更加清晰的变化图：

另：
在参考代码的基础上，对映射像素进行了插值处理，可以使图像更加平滑，原理如下：

主要函数代码：

function resultPic=createCubeMapFace(oriPic,id,height,width)    [M,N,~]=size(oriPic);    resultPic=zeros([height,width,3]);    an=sin(pi/4);    ak=cos(pi/4);        faceTransform=[0,0;               pi/2,0;               pi,0;               -pi/2,0;               0,-pi/2;               0,pi];    ftu=faceTransform(id,1);    ftv=faceTransform(id,2);    for y=0:height-1        for x=0:width-1            nx=y/height-0.5;            ny=x/width-0.5;            nx=nx*2*an;            ny=ny*2*an;            if (ftv == 0)                u=atan2(nx, ak);                v=atan2(ny*cos(u),ak);                u=u+ftu;            elseif(ftv>0)                d=sqrt(nx*nx+ny*ny);                v=pi/2-atan2(d,ak);                u=atan2(ny,nx);            else                d=sqrt(nx*nx+ny*ny);                v=-pi/2+atan2(d,ak);                u=atan2(-ny,nx);            end            u=u/(pi);            v=v/(pi/2);            while(v<-1)                v=v+2;                u=u+1;            end            while(v>1)                v=v-2;                u=u+1;            end            while(u<-1)                u=u+2;            end            while(u>1)                u=u-2;            end            u=u/2+0.5;            v=v/2+0.5;            u=u*(N-1)+1;            v=v*(M-1)+1;                        fv=floor(v);fv1=floor(v)+1;pv=v-fv;fv1(fv1>M)=M;            fu=floor(u);fu1=floor(u)+1;pu=u-fu;fu1(fu1>N)=N;            resultPic(x+1,y+1,:)=double(oriPic(fv,fu,:)).*(1-pv).*(1-pu)+...                                 double(oriPic(fv1,fu,:)).*(pv).*(1-pu)+...                                 double(oriPic(fv,fu1,:)).*(1-pv).*(pu)+...                                 double(oriPic(fv1,fu1,:)).*(pv).*(pu);        end    end    resultPic=uint8(resultPic);end

函数调用及图像存储：
这里后面长宽数值可以任意设定，但是要求长宽数值一致，如果按照当前写法，结果被存储至result文件夹：

if ~exist('result','dir')   mkdir('result');endfor i=1:6    resultPic=createCubeMapFace(oriPic,i,500,500);    figure(i)    imshow(resultPic)    imwrite(resultPic,['result\',num2str(i),'.jpg'])end

另： 如图所示
图片序号[1,2,3,4,5,6]分别对应图片[右，后，左，前，上，下]

1.3 完整代码

function panoramic2boxoriPic=imread('889027-884424860.jpg');[rows,cols,~]=size(oriPic);for i=cols:-1:1    tempListR=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    tempListG=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    tempListB=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    if all(round(tempListR-mean(tempListR))==0)&&all(tempListR==tempListG)&&all(tempListR==tempListB)        oriPic(:,i,:)=[];    else        break;    endendoriPic=oriPic(:,end:-1:1,:);for i=size(oriPic,2):-1:1    tempListR=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    tempListG=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    tempListB=oriPic(floor(rows/4):ceil(3*rows/4),i,1);    if all(round(tempListR-mean(tempListR))==0)&&all(tempListR==tempListG)&&all(tempListR==tempListB)        oriPic(:,i,:)=[];    else        break;    endendoriPic=oriPic(:,end:-1:1,:);for i=rows:-1:1    tempListR=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    tempListG=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    tempListB=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    if all(round(tempListR-mean(tempListR))==0)&&all(tempListR==tempListG)&&all(tempListR==tempListB)        oriPic(i,:,:)=[];    else        break;    endendoriPic=oriPic(end:-1:1,:,:);for i=size(oriPic,1):-1:1    tempListR=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    tempListG=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    tempListB=oriPic(i,floor(cols/4):ceil(3*cols/4),1);    if all(round(tempListR-mean(tempListR))==0)&&all(tempListR==tempListG)&&all(tempListR==tempListB)        oriPic(i,:,:)=[];    else        break;    endendoriPic=oriPic(end:-1:1,:,:);% =========================================================================if ~exist('result','dir')   mkdir('result');endfor i=1:6    resultPic=createCubeMapFace(oriPic,i,500,500);    figure(i)    imshow(resultPic)    imwrite(resultPic,['result\',num2str(i),'.jpg'])end% =========================================================================function resultPic=createCubeMapFace(oriPic,id,height,width)    [M,N,~]=size(oriPic);    resultPic=zeros([height,width,3]);    an=sin(pi/4);    ak=cos(pi/4);        faceTransform=[0,0;               pi/2,0;               pi,0;               -pi/2,0;               0,-pi/2;               0,pi];    ftu=faceTransform(id,1);    ftv=faceTransform(id,2);    for y=0:height-1        for x=0:width-1            nx=y/height-0.5;            ny=x/width-0.5;            nx=nx*2*an;            ny=ny*2*an;            if (ftv == 0)                u=atan2(nx, ak);                v=atan2(ny*cos(u),ak);                u=u+ftu;            elseif(ftv>0)                d=sqrt(nx*nx+ny*ny);                v=pi/2-atan2(d,ak);                u=atan2(ny,nx);            else                d=sqrt(nx*nx+ny*ny);                v=-pi/2+atan2(d,ak);                u=atan2(-ny,nx);            end            u=u/(pi);            v=v/(pi/2);            while(v<-1)                v=v+2;                u=u+1;            end            while(v>1)                v=v-2;                u=u+1;            end            while(u<-1)                u=u+2;            end            while(u>1)                u=u-2;            end            u=u/2+0.5;            v=v/2+0.5;            u=u*(N-1)+1;            v=v*(M-1)+1;                        fv=floor(v);fv1=floor(v)+1;pv=v-fv;fv1(fv1>M)=M;            fu=floor(u);fu1=floor(u)+1;pu=u-fu;fu1(fu1>N)=N;            resultPic(x+1,y+1,:)=double(oriPic(fv,fu,:)).*(1-pv).*(1-pu)+...                                 double(oriPic(fv1,fu,:)).*(pv).*(1-pu)+...                                 double(oriPic(fv,fu1,:)).*(1-pv).*(pu)+...                                 double(oriPic(fv1,fu1,:)).*(pv).*(pu);        end    end    resultPic=uint8(resultPic);endend

1.4 其他几组切割结果

图片源自：https://www.cgmodel.com/article/9004.html

part2 盒图展示

2.1 曲面绘制

使用surf绘制各个曲面后，并为各个曲面贴图：

for i=1:6    oriPic.(['p',num2str(i)])=imread(['result\',num2str(i),'.jpg']);   end[rows,cols,~]=size(oriPic.p1);[baseXY,baseZ]=meshgrid(1:cols,rows:-1:1);ax=gca;hold(ax,'on')surf(baseXY(:,end:-1:1)-(1+rows)/2,-(rows-1)./2.*ones(size(baseXY)),baseZ,'CData',oriPic.p1,'EdgeColor','none','FaceColor','interp')surf(-(rows-1)./2.*ones(size(baseXY)),baseXY-(1+rows)/2,baseZ,'CData',oriPic.p2,'EdgeColor','none','FaceColor','interp')surf(baseXY-(1+rows)/2,(rows-1)./2.*ones(size(baseXY)),baseZ,'CData',oriPic.p3,'EdgeColor','none','FaceColor','interp')surf((rows-1)./2.*ones(size(baseXY)),baseXY(:,end:-1:1)-(1+rows)/2,baseZ,'CData',oriPic.p4,'EdgeColor','none','FaceColor','interp')surf(baseXY'-(1+rows)/2,baseXY-(1+rows)/2,ones(size(baseXY)),'CData',oriPic.p6(end:-1:1,end:-1:1,:),'EdgeColor','none','FaceColor','interp')surf(baseXY'-(1+rows)/2,baseXY-(1+rows)/2,rows-1+ones(size(baseXY)),'CData',oriPic.p5(:,end:-1:1,:),'EdgeColor','none','FaceColor','interp')

2.2 视角调整

通过设置axes属性将视角调整至盒子里面

ax=axes('parent',fig,'position',[-0.45 -0.45 1.9 1.9]);hold(ax,'on')ax.ZLim=[0,rows+1];ax.XLim=[0-(1+rows)/2,rows+1-(1+rows)/2];ax.YLim=[0-(1+rows)/2,rows+1-(1+rows)/2];ax.Color=[0 0 0];ax.CameraPosition=[0,0,rows/2];ax.CameraPositionMode='manual';ax.DataAspectRatio=[1,1,1];ax.DataAspectRatioMode='manual';ax.Projection='perspective';ax.CameraTargetMode='manual';ax.CameraViewAngle = 7;ax.View=[-2.7391 90.0000];ax.CameraTarget=[0 0 (rows-1)/2];ax.Toolbar.Visible='on';

运行后点击那个三位旋转按钮即可开始漫游

此时的盒图是无缝隙版本，有缝隙版放在后面

2.3 完整代码

无缝隙版：

function showBoxfor i=1:6    oriPic.(['p',num2str(i)])=imread(['result\',num2str(i),'.jpg']);   end[rows,cols,~]=size(oriPic.p1);[baseXY,baseZ]=meshgrid(1:cols,rows:-1:1);fig=figure('units','pixels','position',[300 80 500 500],...                       'Numbertitle','off','menubar','none','resize','off',...                       'name','box');                   ax=axes('parent',fig,'position',[-0.45 -0.45 1.9 1.9]);hold(ax,'on')ax.ZLim=[0,rows+1];ax.XLim=[0-(1+rows)/2,rows+1-(1+rows)/2];ax.YLim=[0-(1+rows)/2,rows+1-(1+rows)/2];ax.Color=[0 0 0];ax.CameraPosition=[0,0,rows/2];ax.CameraPositionMode='manual';ax.DataAspectRatio=[1,1,1];ax.DataAspectRatioMode='manual';ax.Projection='perspective';ax.CameraTargetMode='manual';ax.CameraViewAngle = 7;ax.View=[-2.7391 90.0000];ax.CameraTarget=[0 0 (rows-1)/2];ax.Toolbar.Visible='on';surf(baseXY(:,end:-1:1)-(1+rows)/2,-(rows-1)./2.*ones(size(baseXY)),baseZ,'CData',oriPic.p1,'EdgeColor','none','FaceColor','interp')surf(-(rows-1)./2.*ones(size(baseXY)),baseXY-(1+rows)/2,baseZ,'CData',oriPic.p2,'EdgeColor','none','FaceColor','interp')surf(baseXY-(1+rows)/2,(rows-1)./2.*ones(size(baseXY)),baseZ,'CData',oriPic.p3,'EdgeColor','none','FaceColor','interp')surf((rows-1)./2.*ones(size(baseXY)),baseXY(:,end:-1:1)-(1+rows)/2,baseZ,'CData',oriPic.p4,'EdgeColor','none','FaceColor','interp')surf(baseXY'-(1+rows)/2,baseXY-(1+rows)/2,ones(size(baseXY)),'CData',oriPic.p6(end:-1:1,end:-1:1,:),'EdgeColor','none','FaceColor','interp')surf(baseXY'-(1+rows)/2,baseXY-(1+rows)/2,rows-1+ones(size(baseXY)),'CData',oriPic.p5(:,end:-1:1,:),'EdgeColor','none','FaceColor','interp')end

有缝隙版：

function showBox2for i=1:6    oriPic.(['p',num2str(i)])=imread(['result\',num2str(i),'.jpg']);   end[rows,cols,~]=size(oriPic.p1);[baseXY,baseZ]=meshgrid(1:cols,rows:-1:1);fig=figure('units','pixels','position',[300 80 500 500],...                       'Numbertitle','off','menubar','none','resize','off',...                       'name','box');                   ax=axes('parent',fig,'position',[-0.45 -0.45 1.9 1.9]);hold(ax,'on')ax.ZLim=[0,rows+1];ax.XLim=[0-(1+rows)/2,rows+1-(1+rows)/2];ax.YLim=[0-(1+rows)/2,rows+1-(1+rows)/2];ax.Color=[0 0 0];ax.CameraPosition=[0,0,rows/2];ax.CameraPositionMode='manual';ax.DataAspectRatio=[1,1,1];ax.DataAspectRatioMode='manual';ax.Projection='perspective';ax.CameraTargetMode='manual';ax.CameraViewAngle = 7;ax.View=[-2.7391 90.0000];ax.CameraTarget=[0 0 (rows+1)/2];ax.Toolbar.Visible='on';surf(baseXY(:,end:-1:1)-rows/2,-rows./2.*ones(size(baseXY)),baseZ,'CData',oriPic.p1,'EdgeColor','none','FaceColor','interp')surf(-rows./2.*ones(size(baseXY)),baseXY-(1+rows)/2,baseZ,'CData',oriPic.p2,'EdgeColor','none','FaceColor','interp')surf(baseXY-(1+rows)/2,rows./2.*ones(size(baseXY)),baseZ,'CData',oriPic.p3,'EdgeColor','none','FaceColor','interp')surf(rows./2.*ones(size(baseXY)),baseXY(:,end:-1:1)-(1+rows)/2,baseZ,'CData',oriPic.p4,'EdgeColor','none','FaceColor','interp')surf(baseXY'-(1+rows)/2,baseXY-(1+rows)/2,zeros(size(baseXY)),'CData',oriPic.p6(end:-1:1,end:-1:1,:),'EdgeColor','none','FaceColor','interp')surf(baseXY'-(1+rows)/2,baseXY-(1+rows)/2,rows+ones(size(baseXY)),'CData',oriPic.p5(:,end:-1:1,:),'EdgeColor','none','FaceColor','interp')end

以上是“MATLAB全景图切割及盒图显示怎么实现”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注编程网行业资讯频道！