JPEG.zip_DCT直流系数_DCT量化_JPEG DCT_dct系数_jpeg ac dc matlab

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % main 主程序 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% clear all; I=imread('claire1.bmp'); %读入原始图像 I1=double(I); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 假设图像大小为SATURN.bmp（438×328） % imgcolnumber 代表图形的长，即图像矩阵所有的列数－438 % imgrownumber 代表图像的高，即图像矩阵所有的行数－328 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% [imgrownumber, imgcolnumber]=size(I); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % B=blkproc(A,[m n],fun,p1,p2...):应用函数fun对图像A的每个不同的m×n块进行处理， % 必要的时候可对A的四周补0。 p1、p2为附加的传送给fun的参数。 % “.*”表示矩阵对应元素向量乘法，“*”表示矩阵乘法。 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% T=dctmtx(8); B=blkproc(I1,[8 8],'P1*x*P2',T,T'); % T和T'转置是DCT函数P1*x*P2的参数 % P1和P2是函数的参数,其中P1=T,而P2=T'(就是T的转置) x表示前面的I[8 8] % 'P1*x*P2'在这里代替fun。 %下面这个mask就是书上278页表10.2(a) JPEG量化步长矩阵 mask=[16 11 10 16 24 40 51 61 12 12 14 19 26 58 60 55 14 13 16 24 40 57 69 56 14 17 22 29 51 87 80 62 18 22 37 56 68 109 103 77 24 35 55 64 81 104 113 92 49 64 78 87 103 121 120 101 72 92 95 98 112 100 103 99]; % 请大家重新定义一个mask，以演示不同的系数对重建图像的影响。 % 。。。。。。。。。。。。。 B1=blkproc(B,[8,8],'round(x./P1)',mask); B2=blkproc(B1,[8,8],'x.*P1',mask); I2=blkproc(B2,[8,8],'P1*x*P2',T',T); %%% 用下面这两句表示在同一个figure内画两幅图 %请学生完成语句，添加图的名字，因为一页中有两个图，请区别哪一个是原始图像，哪一个是重建图像 figure; subplot(1,2,1),imshow(uint8(I)); %。。。。。。。。。 subplot(1,2,2),imshow(uint8(I2)); %。。。。。。。。。 %%% 用下面这两句表示出现两个figure，每个figure内画一幅图 % 请大家编写语句完成图像的显示，要求一页只显示一个图，且带有图的名字。 % 。。。。。。。。。