Image1=im2double（imread（‘1.jpg‘））;?
gray=rgb2gray（Image1）;?
imhist（gray）;?
[hw]=size（gray）;?
NewImage1=zeros（hw）;?
NewImage3=zeros（hw3）;

%灰度級——彩色變換
for?x=1:w
for?y=1:h
if?gray（yx）<64/256
NewImage3（yx1）=0;
NewImage3（yx2）=4*gray（yx）;
NewImage3（yx3）=1;
elseif?gray（yx）<128/256
NewImage3（yx1）=0;
NewImage3（yx2）=1;
NewImage3（yx3）=2-4*gray（yx）;
elseif?gray（yx）<192/256
NewImage3（yx1）=4*gray（yx）-2;
NewImage3（yx2）=1;
NewImage3（yx3）=0;
else
NewImage3（yx1）=1;
NewImage3（yx2）=4-4*gray（yx）;
NewImage3（yx3）=0;
end
end
end
figureimshow（NewImage3）title（‘灰度級—彩色變換‘）;

%彩虹編碼灰度級——彩色變換
for?x=1:w?

?????for?y=1:h?

?????????if?gray（yx）<32/256?

??????????????NewImage3（yx1）=0;?

??????????????NewImage3（yx2）=0;?
??????????????NewImage3（yx3）=255*（gray（yx）/32）;?

?????????elseif?gray（yx）<64/256?

??????????????NewImage3（yx1）=0;?

??????????????NewImage3（yx2）=255*（（gray（yx）-32）/32）;?

??????????????NewImage3（yx3）=255;?

?????????elseif?gray（yx）<96/256?

??????????????NewImage3（yx1）=0;?

??????????????NewImage3（yx2）=255;?

??????????????NewImage3（yx3）=255*（（（96-gray（yx））/32））;?
?????????elseif?gray（yx）<128/256?

??????????????NewImage3（yx1）=255*（（gray（yx）-96）/32）;?

??????????????NewImage3（yx2）=255;?

??????????????NewImage3（yx3）=0;?
?????????elseif?gray（yx）<192/256?

??????????????NewImage3（yx1）=2