error-different values for same image

I am performing feature extraction,i have 80 images in data base,i am extracting 3 features,and have saved ,them,next am taking first image from that 80 images and have extracted same features .and have saved it.

wen i compare i get different same values for 2 feature extraction and for third feature extraction ,i get different values

the feature extraction aye

two colours and one texture

the code for texture is

g=rgb2gray(I);
rgb=mean(mean(I));
r1=rgb(:,:,1);
g1=rgb(:,:,2);
b1=rgb(:,:,3);
std1=std2(g);
entropy1=entropy(g);
tres=graythresh(g);
glcm=graycomatrix(g);
F=graycoprops(glcm,{'Contrast','Homogeneity','Correlation','Energy'});%graycoprops(glcm, properties)
%calculates the statistics specified in properties from the gray-level co-occurence matrix glcm
 contrast=F.Contrast;
 homogeneity=F.Homogeneity;
 correlation=F.Correlation;
 energy=F.Energy;
 final_tex=[contrast,homogeneity,correlation,energy];
 final_textq=final_tex;
save('final_text_Query',  'final_textq');
FinalOut2_Query = final_tex

please help

[Walter Roberson]

You somehow left out your question.

Answer 1

[Walter Roberson]

There is no reason to expect that different features will always give the same value. Feature extraction uses multiple features. When you do CBIR you match against the multiple features and come up with a majority or "most matches" or consensus decision knowing that not every feature will match.

Answer 2

[Image Analyst]

Either your image is not the same like you thought it was, or you ran a different piece of code on the same image. Because running the same set of code on the same image will give the same result, unless you somehow used a function call to a random number generator (like rand, randi, randperm, etc.).