how to resize an image as per the required dimension

41 次查看（过去 30 天）
ramya s
ramya s 2011-3-16
评论： Walter Roberson 2023-5-16
i am doing my final yr project on steganography. and my project s suit only for square matrix images. (i.e, 256*256 512*512 1024*1024) like that images. i need images for that. wen i tried to resize other images it does not works.
for eg., I=imread('post.jpg');
[m n] = size(I)
J = imresize(I, [256 256]);
[x y] = size(J)
the output i m getting is m = 324 n = 512
x = 256 y = 1156
i do not know why it is like this. i am not getting any errors. help me what to do what shall i do now? please help me its very urgent
  2 个评论
Sarah Wait Zaranek
Sarah Wait Zaranek 2011-3-16
I =randi(324,512,'uint8');
[m n] = size(I) ;
J = imresize(I, [256 256]);
[x y] = size(J);
This works for me.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2011-3-16
Your image is 3 dimensional (RGB), not 2 dimensional.

更多回答（3 个）

shyama p
shyama p 2011-3-17
编辑：Walter Roberson 2017-11-9
I1=imread('post.jpg');
I2 = imresize(I1,[256 256]);
In=rgb2gray(I2); % use if the image containing RGB value 3
figure;imshow(In);
imwrite(In,'yi.jpg') ;
dipa teraiya
dipa teraiya 2018-4-24
hello friends i have image of dimension is 84 * 34 and size of image is 16.1 KB Now other image of dimension is same but size of image is different is 16.4 KB so pls tell me which code can be applied when increase the size of image?
salman saleem
salman saleem 2020-10-12
My question is how we can reduce the size of image by taking mean?
  1 个评论
Walter Roberson
Walter Roberson 2023-5-16
Ran in:
Suppose that you replace each N x N block of pixels with the mean value of the pixels in that block. Then your image with be 1/N times as large, but still similar.
For example:
img = imread('flamingos.jpg');
imgd = im2double(img);
img2x2 = (imgd(1:2:end,1:2:end,:) + imgd(1:2:end,2:2:end,:) + imgd(2:2:end,1:2:end,:) + imgd(2:2:end,2:2:end,:))./(2*2);
imshow(imgd); title('original');
imshow(img2x2); title('mean of 2x2 blocks')
whos img img2x2
Name Size Bytes Class Attributes img 972x1296x3 3779136 uint8 img2x2 486x648x3 7558272 double
You can see that the two images are visually very very similar, but the second image is only half the number of rows and columns of the first image.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Neighborhood and Block Processing 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by