matlab之影像处理（下）

【参看：https://www.bilibili.com/video/av14503445/?p=9】

目录

影像变为黑白影像：

​

graythresh()和im2bw()

预测背景

计算一共有多少米：

bwlabel()

用颜色标注：label2rgb()

regionprops()

---

影像变为黑白影像：

 

graythresh()和im2bw()

I = imread('rice.png');
level=graythresh(I);
bw =im2bw(I,level); subplot(1,2,1); imshow(I);
subplot(1,2,2); imshow(bw);

预测背景

>> BG =imopen(I,strel('disk',15));
>> imshow(BG);
>> 

I = imread('rice.png'); level = graythresh(I);
bw = im2bw(I,level); subplot(1,2,1); 
imshow(bw); BG = imopen(I,strel('disk',15));
I2 = imsubtract(I,BG); level = graythresh(I2);
bw2 = im2bw(I2,level);
subplot(1,2,2); imshow(bw2);

计算一共有多少米：

bwlabel()

>> I = imread('rice.png');
>> BG =imopen(I,strel('disk',15));
>> I2 = imsubtract(I,BG); level = graythresh(I2);
>> BW = im2bw(I2,level);
>> [labeled, numObjects] = bwlabel(BW,8);
>> numObjects

numObjects =

    99

>> 

【99粒米】

用颜色标注：label2rgb()

>> I = imread('rice.png');
>> BG =imopen(I,strel('disk',15));
>> I2 = imsubtract(I,BG); level = graythresh(I2);
>> BW = im2bw(I2,level);
>> [labeled, numObjects] = bwlabel(BW,8);
>> RGB_label = label2rgb(labeled);imshow(RGB_label);

regionprops()

得到图片的一些特性：

>> I = imread('rice.png');
>> BG =imopen(I,strel('disk',15));
>> I2 = imsubtract(I,BG); level = graythresh(I2);
>> BW = im2bw(I2,level);
>> [labeled, numObjects] = bwlabel(BW,8);
>> graindata = regionprops(labeled,'basic');
>> graindata(51)

ans = 

           Area: 155
       Centroid: [112.4258 245.8645]
    BoundingBox: [108.5000 234.5000 8 22]

>> 

 

 

>> I = imread('rice.png');
>> level = graythresh(I);
>> BG =imopen(I,strel('disk',15));
>> I2 = imsubtract(I,BG); 
>> BW = im2bw(I2,graythresh(I2));
>> ObjI = bwselect(BW); imshow(ObjI);

【可以选择要显示的米粒。】