matlab 將圖片進行切割

function bw2 = edu_imgcrop(bw)

% Find the boundary of the image
[y2temp x2temp] = size(bw);
x1=1;
y1=1;
x2=x2temp;
y2=y2temp;

% Finding left side blank spaces
cntB=1;
while (sum(bw(:,cntB))==y2temp)
    x1=x1+1;
    cntB=cntB+1;
end

% Finding right side blank spaces
cntB=1;
while (sum(bw(cntB,:))==x2temp)
    y1=y1+1;
    cntB=cntB+1;
end

% Finding upper side blank spaces
cntB=x2temp;
while (sum(bw(:,cntB))==y2temp)
    x2=x2-1;
    cntB=cntB-1;
end

% Finding lower side blank spaces
cntB=y2temp;
while (sum(bw(cntB,:))==x2temp)
    y2=y2-1;
    cntB=cntB-1;
end

% Crop the image to the edge
bw2=imcrop(bw,[x1,y1,(x2-x1),(y2-y1)]); %imcrop
%imcrop(I, rect) crops the image I. rect is a four-element position vector[xmin ymin width height] that specifies the size and position of the crop rectangle.

思路：1、找到需要切邊的四個點，分別問左上、右上、左下、右下；

2、用imcrop切邊即可；