提取橢圓區域並用Matlab手動裁剪它

Question

我有很多人臉圖像，我想通過手動和裁剪從圖像中提取一個橢圓區域並自動保存（像imcrop但不是矩形）。 你能幫我解釋一下嗎？

感謝您的幫助

Answer 1

可以使用imellipse功能。

Answer 2

%This is what you would do after creating the mask to get the coordinates. 

structBoundaries = bwboundaries(binaryImage); 
xy=structBoundaries{1}; % Get n by 2 array of x,y coordinates. 
x = xy(:, 2); % Columns. 
y = xy(:, 1); % Rows. 

但是，更好的方法是使用下面的代碼。實質上，它要求用戶選擇圖像，然後用戶手動裁剪圖像，然後將其保存到原始圖像的位置。

[FileName,PathName] = uigetfile({'*.jpg;*.tif;*.png;*.gif','All Image Files'},'Please Select an Image'); 
image = imread([PathName FileName]); 
imshow(image) %needed to use imellipse 
user_defined_ellipse = imellipse(gca, []); % creates user defined ellipse object. 
wait(user_defined_ellipse);% You need to click twice to continue. 
MASK = double(user_defined_ellipse.createMask()); 
new_image_name = [PathName 'Cropped_Image_' FileName]; 
new_image_name = new_image_name(1:strfind(new_image_name,'.')-1); %removing the .jpg, .tiff, etc 
new_image_name = [new_image_name '.png']; % making the image .png so it can be transparent 
imwrite(image, new_image_name,'png','Alpha',MASK); 
msg = msgbox(['The image was written to ' new_image_name],'New Image Path'); 
waitfor(msg);