读取BMP信息并显示的MATLAB程序

clc;clear all;close all; fid=fopen( 't_2.bmp','rb');%此处为想要读取的文件名 bfType=fread(fid,2); [s, errmsg] = sprintf('the file type:%s',char(bfType)); disp(s); bfSize=fread(fid,4); fsize=bfSize(4)*256^3+bfSize(3)*256^2+bfSize(2)*256+bfSize(1); [s, errmsg] = sprintf('the file size:%d byte',fsize); disp(s); bfOffbits=fread(fid,8); foffset=bfOffbits(8)*256^3+bfOffbits(7)*256^2+bfOffbits(6)*256+bfOffbits(5); [s, errmsg] = sprintf('offset to start of pixel data:%d byte',foffset); disp(s); biSize=fread(fid,4); isize=biSize(4)*256^3+biSize(3)*256^2+biSize(2)*256+biSize(1); [s, errmsg] = sprintf('the size of infoheader:%d byte',isize); disp(s); infoRead=fread(fid,8); biWidth=infoRead(4)*256^3+infoRead(3)*256^2+infoRead(2)*256+infoRead(1); biHeight=infoRead(8)*256^3+infoRead(7)*256^2+infoRead(6)*256+infoRead(5); [s, errmsg] = sprintf('width: %d \nheight:%d ',biWidth,biHeight); disp(s); infoRead=fread(fid,28); biBitCount=infoRead(4)*256+infoRead(3); biCompression=infoRead(8)*256^3+infoRead(7)*256^2+infoRead(6)*256+infoRead(5); biSizeImage=infoRead(12)*256^3+infoRead(11)*256^2+infoRead(10)*256+infoRead(9); biXPelsPerMeter=infoRead(16)*256^3+infoRead(15)*256^2+infoRead(14)*256+infoRead(13); biYPelsPerMeter=infoRead(20)*256^3+infoRead(19)*256^2+infoRead(18)*256+infoRead(17); biCirUsed=infoRead(24)*256^3+infoRead(23)*256^2+infoRead(22)*256+infoRead(21); biCirImportant=infoRead(28)*256^3+infoRead(27)*256^2+infoRead(26)*256+infoRead(25); [s, errmsg] = sprintf('the bit count: %d, color count: %d',... biBitCount,2^biBitCount); disp(s); if biCompression==0 disp('no compression'); else if biCompression==1 disp('RLE8 compression'); else if biCompression==2 disp('RLE4 compression'); else disp('bit fields compression'); end end end if biXPelsPerMeter~=0 [s, errmsg] = sprintf('horizontal resolution:%d pixels per meter',biXPelsPerMeter); disp(s); else disp('default horizontal resulution'); end if biYPelsPerMeter~=0 [s, errmsg] = sprintf('verticular resolution:%d pixels per meter',biYPelsPerMeter); disp(s); else disp('default verticular resulution'); end if biSizeImage~=0 [s, errmsg] = sprintf('image size: %d',biSizeImage); disp(s); else disp('No compression'); end if biCirUsed~=0 [s, errmsg] = sprintf('%d color actually used',biCirUsed); disp(s); else disp('all colors are used'); end if biCirImportant~=0 [s, errmsg] = sprintf('count of significant colors:%d',biCirImportant); disp(s); else disp('all colors are significant'); end skip=mod((4-mod(((biWidth * biBitCount)/8),4)),4); if ((biBitCount==24)&&(foffset==54)) for i=1:biHeight if biHeight>0 indHeight=biHeight+1-i; else indHeight=i; end for j=1:biWidth colorRead=fread(fid,3); I(indHeight,j,1)=colorRead(3); I(indHeight,j,2)=colorRead(2); I(indHeight,j,3)=colorRead(1); end fread(fid,skip); end else if(biBitCount==32)&&(bfOffbits==54) for i=1:biHeight if biHeight>0 indHeight=biHeight+1-i; else indHeight=i; end for j=1:biWidth colorRead=fread(fid,4); I(indHeight,j,1)=colorRead(3); I(indHeight,j,2)=colorRead(2); I(indHeight,j,3)=colorRead(1); end fread(fid,skip); end else LUT=fread(fid,(2^biBitCount)*4); for i=1:biHeight if biHeight>0 indHeight=biHeight+1-i; else indHeight=i; end for j=1:biWidth LUTIndex=fread(fid,1); I(indHeight,j,1)=LUT(LUTIndex*4+3); I(indHeight,j,2)=LUT(LUTIndex*4+2); I(indHeight,j,3)=LUT(LUTIndex*4+1); end fread(fid,skip); end end end imshow(uint8(I)),title('Display BMP')