Matlab函式im2double简介

函式名称： im2double

如果图像img是double型的，d=img;如果图像是logical或single型图像，d=double(img);如果图像是uint8型，d=double(img)/255;如果图像是uint16型，d=double(img)/65535;

在matlab命令行视窗输入edit im2double，回车，打开im2double.m档案，部分代码如下：

iptchecknargin(1,2,nargin,mfilename);

iptcheckinput(img,{'double','logical','uint8','uint16','int16','single'},{}, ...

mfilename,'Image',1);

if nargin == 2

iptcheckstrs(typestr, {'indexed'}, mfilename, 'type', 2);

end

if isa(img, 'double') %如果图像是double型的，图像处理前后不变

d = img;

elseif isa(img, 'logical') || isa(img, 'single') % 如果图像是逻辑图像或single类型图像，直接转换成double型

d = double(img);

elseif isa(img, 'uint8') || isa(img, 'uint16') %uint8型图像，range(2)=255;uint16型图像,range(2)=65535;

if nargin==1

range = getrangefromclass(img);

d = double(img) / range(2); %即d=double(img)/255或d=double(img)/65535;

else

d = double(img)+1;

end

else %int16

if nargin == 1

d = (double(img) + 32768) / 65535;

else

eid = sprintf('Images:%s:invalidIndexedImage',mfilename);

error(eid,'An indexed image can be uint8, uint16, double, %s', ...

'single, or logical.');

end

end