How to create an array and combine and put two images into it

Hi.

So far, I have the following code:

A = imread('Yuan.jpg');

ACrop = A(300:1300, 300:1051);

imshow(ACrop)

B = imread('Jacky.jpg');

BCrop = B(1:225, 88:283);

imshow(BCrop)

I have two images cropped. I want to combine ACrop and BCrop together with ACrop on the left and BCrop on the left. How do I create an array so that I may combine two images into one in the array?

Thanks.

Answer 1

[Setsuna Yuuki.]

Maybe you need to resize or add white pixels so that the images have the same dimension.

A = imread('Yuan.jpg');
ACrop = A(300:1300, 300:1051);
imshow(ACrop)
B = imread('Jacky.jpg');
BCrop = B(1:225, 88:283);
imshow(BCrop)

[qq,ww,ee] = size(Acrop); 
matrix = 255*uint8(ones(qq,ww,ee)); %Image with pixels in 255 (White)
[rr,tt,yy] = size(Bcrop);

matrix(1:rr,1:tt,:) = Bcrop(:,:,:); %add Bcrop to the white matrix

umi = [ACrop, matrix]; %concatenate
imshow(umi)
%or
umi = [ACrop;matrix]; %concatenate
imshow(umi)

with resize:

A = imread('Yuan.jpg');
ACrop = A(300:1300, 300:1051);
imshow(ACrop)
B = imread('Jacky.jpg');
BCrop = B(1:225, 88:283);
imshow(BCrop)

[qq,ww,ee] = size(Acrop); 
Bcrop = imresize(Bcrop,[qq ww]);

umi = [ACrop, Bcrop]; %concatenate
imshow(umi)
%or
umi = [ACrop;Bcrop]; %concatenate
imshow(umi)

[Yuan Yuan Lin]

[qq,ww,ee] = size(Acrop);

Bcrop = imresize(Bcrop,[qq ww]);

What do these two lines mean? Why are there three values in [qq, ww, ee]? And why does BCrop only use [qq, ww]?

[Setsuna Yuuki.]

%[qq,ww,ee] = size(Acrop); %row size, column size, channels [RGB] (if you don't need the channels, you can skip ee)
[qq,ww,~] = size(Acrop); % Is the same but without the channels
Bcrop = imresize(Bcrop,[qq ww]); % It Resize Bcrop with row size and column size of Acrop

[Yuan Yuan Lin]

I see. Now I have a new problem. The cropped images turned to be black and white. How do I retain its color after cropping it?

final = [ACrop, BCrop];

gray = rgb2gray(final);

imshow(gray)

Also, trying to convert rgb image to grayscale doesn't seem to work as the function edge() doesn't seem to work on gray.

[Setsuna Yuuki.]

You need all channels of the image (red,green,blue).

%% change
ACrop = A(300:1300, 300:1051);
BCrop = B(1:225, 88:283);
%% to
ACrop = A(300:1300, 300:1051,:); 
BCrop = B(1:225, 88:283,:);

[Yuan Yuan Lin]

[qq, ww, ee] = size(ACrop);

BCrop = imresize(BCrop, [qq, ww]);

final = [ACrop, BCrop];

The ee value is the channel that has been added. Tried adding ee to [qq, ww] for BCrop but the combined image is still black and white. final = [ACrop, BCrop, :]; doesn't seem to be the correct way of writing it. Any way to write it so that it retains its rgb?

[Setsuna Yuuki.]

when you crop the image, you must do with 3 channels.

A = imread('Yuan.jpg');
ACrop = A(300:1300, 300:1051,:);% : --> 3 channels
imshow(ACrop)
B = imread('Jacky.jpg');
BCrop = B(1:225, 88:283,:); % : --> 3 channels
imshow(BCrop)
[qq,ww,~] = size(ACrop);
Bcrop = imresize(BCrop,[qq ww]);
umi = [ACrop, Bcrop]; %concatenate
imshow(umi)
%or
umi = [ACrop;Bcrop]; %concatenate
imshow(umi)