Remove background from image

Question

Valnyr Lira 2019-5-3

回答： DGM 2023-4-30

Hi, i'd like to remove the background from RGB images. Since this have to be done in a lot of images i'd like to automate this task.

Original image with background:

The image should be transformed as this one below, without background.

I have cropped the images as the first one, however, i'm getting in trouble to remove the background.

Answer 1

DGM 2023-4-30

% read the image

inpict = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/217934/mx01.jpeg');

% you could use color-based thresholding

% but with the low contrast and chroma, JPG damage is an obstacle

% in this case, there's plenty of object contrast in luma alone

Ymask = rgb2gray(inpict)<128;

Ymask = ~imfill(Ymask,'holes');

% adjust white level

inlevels = stretchlim(inpict).*[0; 1];

outpict = imadjust(inpict,inlevels);

% apply mask

outpict(repmat(Ymask,[1 1 3])) = 255;

imshow(outpict)