基于Matlab绘制超绚丽的烟花的过程详解
时间：2023-01-27 10:13:18 | 栏目：C代码 | 点击：次
1.使用效果
2.随机点生成
我们要构造一个黑色背景，对其添加高斯噪声，然后依据阈值删掉部分噪声，生成一张随机点图片：
% 构造黑色背景并生成白色杂点 blackPic=uint8(zeros(800,800)); distPic=imnoise(blackPic,'gaussian',0, 0.11); distPic(distPic<254)=0;
3.图像膨胀
我们发现之前构造的点太小了，我们要对其进行形态学膨胀处理：
% 杂点膨胀
se=strel('square',3);
distPic=imdilate(distPic,se);
4.特效「风」模拟
就是建立一个循环，不断地将点往右侧复制，并将颜色变暗，代码中第二个参数为拖拽长度，第三个参数为暗化速度：
% 构造风特效
windPic=wind(distPic,180,0.99);
% 风特效构造函数
function resultPic=wind(oriPic,len,ratio)
oriPic=double(oriPic);
for i=1:len
tempPic=[zeros(size(oriPic,1),1),oriPic(:,1:(end-1))].*ratio;
oriPic(oriPic<tempPic)=tempPic(oriPic<tempPic);
end
resultPic=uint8(oriPic);
end
5.级坐标变换
% 极坐标变换
polarPic=polarTransf(windPic(:,end:-1:1)');
% 级坐标变换构造函数
function resultPic=polarTransf(oriPic)
oriPic=double(oriPic);
[m,n]=size(oriPic);
[t,r]=meshgrid(linspace(-pi,pi,n),1:m);
M=2*m;
N=2*n;
[NN,MM]=meshgrid((1:N)-n-0.5,(1:M)-m-0.5);
T=atan2(NN,MM);
R=sqrt(MM.^2+NN.^2);
resultPic=interp2(t,r,oriPic,T,R,'linear',0);
resultPic=uint8(resultPic);
end
6.图像模糊及再映射
我们发现烟花图片中心区域方格化严重：
我们很容易想到图像模糊，但是模糊后亮度又不够，因此我们再做一次映射将图片整体亮度提高：
模糊及映射：
% 模糊以减少像素化 polarPic=imgaussfilt(polarPic,1.5); polarPic=uint8(double(polarPic)./double(max(max(polarPic))).*260);
7.图像上色
生成一个圆形的渐变图片，并与白色烟花图片进行一次正交叠底：
% 构造圆形渐变图
matSize=[1600,1600];
point=[800,800];
colorList=[195 53 93
211 102 141
231 179 192
229 182 172
227 178 137
238 191 147
236 195 113];
% 正片叠底
colorMat=cColorMat(matSize,point,colorList);
colorMatR=colorMat(:,:,1);
colorMatG=colorMat(:,:,2);
colorMatB=colorMat(:,:,3);
fwPicR=double(colorMatR).*double(polarPic)./255;
fwPicG=double(colorMatG).*double(polarPic)./255;
fwPicB=double(colorMatB).*double(polarPic)./255;
fwPic(:,:,1)=fwPicR;
fwPic(:,:,2)=fwPicG;
fwPic(:,:,3)=fwPicB;
fwPic=uint8(fwPic);
imshow(fwPic)
%==========================================================================
% 图像颜色映射函数
function colorMat=cColorMat(matSize,point,colorList)
[xMesh,yMesh]=meshgrid(1:matSize(2),1:matSize(1));
zMesh=sqrt((xMesh-point(2)).^2+(yMesh-point(1)).^2);
zMesh=(zMesh-min(min(zMesh)))./(max(max(zMesh))-min(min(zMesh)));
colorFunc=colorFuncFactory(colorList);
colorMesh=colorFunc(zMesh);
colorMat(:,:,1)=colorMesh(end:-1:1,1:matSize(1));
colorMat(:,:,2)=colorMesh(end:-1:1,matSize(1)+1:2*matSize(1));
colorMat(:,:,3)=colorMesh(end:-1:1,2*matSize(1)+1:3*matSize(1));
colorMat=uint8(colorMat);
end
function colorFunc=colorFuncFactory(colorList)
x=(0:size(colorList,1)-1)./(size(colorList,1)-1);
y1=colorList(:,1);y2=colorList(:,2);y3=colorList(:,3);
colorFunc=@(X)[interp1(x,y1,X,'linear')',...
interp1(x,y2,X,'linear')',...
interp1(x,y3,X,'linear')'];
end
其他几个颜色：
colorList2=[25 59 157
24 71 219
38 124 237
93 215 255
168 244 255
243 254 250
246 252 240];
colorList3=[239 250 210
229 164 122
232 150 138
255 164 204
192 58 111
158 10 26
224 168 121];
8.完整代码
function drawFireWorks
% 构造黑色背景并生成白色杂点
blackPic=uint8(zeros(800,800));
distPic=imnoise(blackPic,'gaussian',0, 0.11);distPic(distPic<254)=0;
% 杂点膨胀
se=strel('square',3);
distPic=imdilate(distPic,se);
% 构造风特效
windPic=wind(distPic,180,0.99);
% 极坐标变换
polarPic=polarTransf(windPic(:,end:-1:1)');
% 模糊以减少像素化
polarPic=imgaussfilt(polarPic,1.5);
polarPic=uint8(double(polarPic)./double(max(max(polarPic))).*260);
%-----------------------------------------------------------------
% 构造圆形渐变图
matSize=[1600,1600];
point=[800,800];
colorList=[195 53 93
211 102 141
231 179 192
229 182 172
227 178 137
238 191 147
236 195 113];
% 正片叠底
colorMat=cColorMat(matSize,point,colorList);
colorMatR=colorMat(:,:,1);
colorMatG=colorMat(:,:,2);
colorMatB=colorMat(:,:,3);
fwPicR=double(colorMatR).*double(polarPic)./255;
fwPicG=double(colorMatG).*double(polarPic)./255;
fwPicB=double(colorMatB).*double(polarPic)./255;
fwPic(:,:,1)=fwPicR;
fwPic(:,:,2)=fwPicG;
fwPic(:,:,3)=fwPicB;
fwPic=uint8(fwPic);
imshow(fwPic)
%==========================================================================
% 风特效构造函数
function resultPic=wind(oriPic,len,ratio)
oriPic=double(oriPic);
for i=1:len
tempPic=[zeros(size(oriPic,1),1),oriPic(:,1:(end-1))].*ratio;
oriPic(oriPic<tempPic)=tempPic(oriPic<tempPic);
end
resultPic=uint8(oriPic);
end
% 极坐标变换构造函数
function resultPic=polarTransf(oriPic)
oriPic=double(oriPic);
[m,n]=size(oriPic);
[t,r]=meshgrid(linspace(-pi,pi,n),1:m);
M=2*m;
N=2*n;
[NN,MM]=meshgrid((1:N)-n-0.5,(1:M)-m-0.5);
T=atan2(NN,MM);
R=sqrt(MM.^2+NN.^2);
resultPic=interp2(t,r,oriPic,T,R,'linear',0);
resultPic=uint8(resultPic);
end
%==========================================================================
% 图像颜色映射函数
function colorMat=cColorMat(matSize,point,colorList)
[xMesh,yMesh]=meshgrid(1:matSize(2),1:matSize(1));
zMesh=sqrt((xMesh-point(2)).^2+(yMesh-point(1)).^2);
zMesh=(zMesh-min(min(zMesh)))./(max(max(zMesh))-min(min(zMesh)));
colorFunc=colorFuncFactory(colorList);
colorMesh=colorFunc(zMesh);
colorMat(:,:,1)=colorMesh(end:-1:1,1:matSize(1));
colorMat(:,:,2)=colorMesh(end:-1:1,matSize(1)+1:2*matSize(1));
colorMat(:,:,3)=colorMesh(end:-1:1,2*matSize(1)+1:3*matSize(1));
colorMat=uint8(colorMat);
end
function colorFunc=colorFuncFactory(colorList)
x=(0:size(colorList,1)-1)./(size(colorList,1)-1);
y1=colorList(:,1);y2=colorList(:,2);y3=colorList(:,3);
colorFunc=@(X)[interp1(x,y1,X,'linear')',...
interp1(x,y2,X,'linear')',...
interp1(x,y3,X,'linear')'];
end
end