selecting an image from folder

I have 30 images in a folder,I have to select only21st image from it,please help,i tried this code but only first image is shown

I have 30 images in folder named photos

     path='D:\photos\';
    files=dir(strcat(path,'*.jpg'))
      for k=1:numel(files(21))%numel(files)
        file_name=files(k).name;
        image_name=strcat(path,file_name);
      I=imread(image_name);
      figure,imshow(I)
      end

[kash]

chandra can u tell how to select 1st,6tf,11th,16th,21st,26th images and storing them in folder

[Image Analyst]

Look up the mod() function to take every 5th one.

Answer 1

[Chandra Kurniawan]

path='D:\photos\';
jpeg_files = dir(fullfile(path,'*.jpg'));

for cnt = 1 : 21
    I{cnt} = imread(fullfile(path,jpeg_files(cnt).name));     
    figure,imshow(I{cnt});
end

[kash]

i get an error when executing it

Cell contents assignment to a non-cell array object.

Error in ==> Untitled at 26

I{cnt} = imread(fullfile(path,jpeg_files(cnt).name));

[Chandra Kurniawan]

what are the size of 'jpeg_files' in workspace?

30x1 struct or 0x1 struct??

[kash]

Chandra I ment i need only the 21st figure and not all 21 figures

[Chandra Kurniawan]

Oh sorry.

Now, you said 21st image in your folder??

Then the code is :

path='D:\photos\';

files = dir(fullfile(path,'*.jpg'));

I = imread(fullfile(path,files(21).name));

figure,imshow(I); title(files(21).name);

This is, right??

[Chandra Kurniawan]

If you consider to select single image,

then you don't need to use for loop

-> for k=1:numel(files(21))

And 'numel(files(21))' is returns 1, you don't need

to write this??

[kash]

tHANKS Chadra

[kash]

Chandra finally one question I have extracted features of images and have stored in .mat file i have 1row and 80 columns of size[1x359double] ,Now i have to take query image and find euclidean distance for image retrieval,can u guide plz

[Chandra Kurniawan]

Euclidean distance is defined as :

D(i,j)=sqrt((dataset1(i,1)-dataset2(j,1))^2 + ...

(dataset1(i,2)-dataset2(j,2))^2);

right??

[Chandra Kurniawan]

What are the size of extracted feature of query image?

[kash]

but i have to retrieve the image how it can be done,have i to extract all the 4 features for that query image and store in .mat file

[Chandra Kurniawan]

Can you show me about 'feature vector of query image' and 'feature vector that you saved in your .MAT file?

[kash]

Feature vector is [1x359double]od 1row and 80 colomns

have i have to extract same feature vector for query image and store in .mat file for retrieving the image

Answer 2

[Chandra Kurniawan]

Then you just need to pass your feature vector 1x80 and

feature vector of query image in

suppose that dataset1 is feature vector 1x80

dataset2 is feature vector of query image

function D = DistEuclidian(dataset1, dataset2)
[m1 n1] = size(dataset1);
[m2 n2] = size(dataset2);
D = zeros(m1, m2);
for i = 1 : m1          
    for j = 1 : m2
        D(i, j) = sqrt((dataset1(i, 1) - dataset2(j, 1)) ^ 2 + ...
                       (dataset1(i, 2) - dataset2(j, 2)) ^ 2);
    end
end

And you'll get the Distance matrix.

Then make a limit. If all values in Distance matrix lower than your limit,

We can say that your query image is match with feature vector 1x80

[FIR]

But Chandra How to retrieve the image finally

[kash]

Chandra how to find the min and max limit please tell,before this can we rank the imaged based on features extraction and calculate indices for that

[kash]

AFter that i need to retrieve the nearest distance image and have to subplot,both query image and retrieved image

[Chandra Kurniawan]

Please send me the MAT file of 'feature vector 1x80'

and tell me what are feature vector of query image.

It's hard if I only imagine about that.

[kash]

this is the feature vector of my dataset image

http://www.sendspace.com/file/s4xidk

feature vector of both the query image and data set image are same images...

the feature vectors are

http://www.sendspace.com/file/6xnrta

[kash]

i have dataset of 80 numbers=[1:1:80]

now i want to take first 8 values ,multiply each value by 2 and divide each by 2,so i will have 8 values each for multiplication and division,and then want to find average for that multilaction values and division values,same way i eant to perform for those 80 values from 1st 8,2nd 8,3rd 8........10th8 please help

[Image Analyst]

Did you try

% Multiply by 2 and divide by 2, for some weird reason.

newVector = (2*data80) / (2*data80); % Not sure of the point.

% Get running average.

output = conv(newVector, ones(1,8)/8, 'valid');