How to save patches of all images in a single .mat file?

1 次查看（过去 30 天）

hirra awan 2020-7-15

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/565568-how-to-save-patches-of-all-images-in-a-single-mat-file

评论： hirra awan 2020-7-18

i have a code that divides image into patches of size 32*32 and also divide the corresponding labeled image into same size of patches. i want to save and concatenate all the patches of all the images in a .mat file, but my code is saving only the patches of last image. please can someone help me with this problem?

a = dir('C:\Users\admin\Desktop\img\*.png');
b = dir('C:\Users\admin\Desktop\lbl\*.png');
for i = 1:length(a)
    filename=strcat('C:\Users\admin\Desktop\img\',a(i).name);
    image=imread(filename);
    R = image(:,:,1);
    G = image(:,:,2);
    B = image(:,:,3);
    Y = 0.299 * R + 0.587 * G + 0.114 * B;
    U = -0.14713 * R - 0.28886 * G + 0.436 * B;
    V = 0.615 * R - 0.51499 * G - 0.10001 * B;
    image = cat(3,Y,U,V);
    [image_patches] = hellopatches(image, 32, 20);
    filenamel=strcat('C:\Users\admin\Desktop\lbl\',b(i).name);
    label=imread(filenamel);
    [labels] = hellopatches_label(label, 32, 20);
    data = cat(1, image_patches,labels);
end
data = data';
 data = shuffleRow(data);
save data.mat;

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

回答（2 个）

neuroDuck 2020-7-15

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/565568-how-to-save-patches-of-all-images-in-a-single-mat-file#answer_466247

编辑：neuroDuck 2020-7-15

Hi Hirra,

You are overwriting 'data' every time the loop runs. Simply index it - e.g. data(i) - or add it to a cat() to make every image accessible outside of the loop.

Kind regards.

10 个评论
显示 8更早的评论隐藏 8更早的评论

Walter Roberson 2020-7-18

hellopatches.m

At present, you create a 3073 x 5625 array for the first image, and a 3073 x 5184 array for the second image.

We know from the above discussion that you do not want to put those two arrays as seperate entries in a cell array.

How would you like to store the 3073 x 5625 array together with the 3073 x 5184 arrary ? Would you want the result to be a 3073 x 10809 array?

I cannot seem to find your source code for hellopatches in the discussion, so I have attached it. It appears to me that since your images are not all the same size, that we should not be necessarily be expecting that the output of hellopatches will always have 3073 rows or 5625 columns.

hirra awan 2020-7-18

Yes exactly I want to store 3073*5625 with 3073*5184 array. This is the data of just 2 images. i have almost 160 images in total. I want the final .mat file to store data like this 3073*10809 .

I attached the hello patches code please check.

请先登录，再进行评论。

Walter Roberson 2020-7-15

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/565568-how-to-save-patches-of-all-images-in-a-single-mat-file#answer_466313

在 MATLAB Online 中打开

data = cat(1, image_patches,labels);

That code is overwriting all of data each iteration.

It looks to me as if data will not be a vector, but I do not seem to be able to locate any hellopatches() function so I cannot tell what shape it will be. As you are not doing imresize() I also cannot be sure that all of the images are the same size, so I cannot be sure that data will be the same size for each iteration. Under the circumstances you should be considering saving into a cell array.

Note: please do not post the same query multiple times. I found at least 9 copies of your query :(