Rank: 450 based on 291 downloads (last 30 days) and 3 files submitted
photo

Avinash Uppuluri

E-mail

Personal Profile:
Professional Interests:

 

Watch this Author's files

 

Files Posted by Avinash View all
Updated   File Tags Downloads
(last 30 days)
Comments Rating
29 Mar 2012 Confusion matrix / Matching matrix along with Precision, Sensitivity, Specificity and Model Accuracy CFMATRIX2 calculates the confusion matrix and related parameters for a classification algo. Author: Avinash Uppuluri statistics, probability, confusion matrix, algorithm, classification, classification algori... 30 9
  • 1.0
1.0 | 1 rating
05 Apr 2010 Screenshot GLCM_Features4.m: Vectorized version of GLCM_Features1.m [With code changes] GLCM_Features4 - Calculates the texture features from the different GLCMs Author: Avinash Uppuluri glcm, texture 44 5
  • 3.0
3.0 | 1 rating
25 Nov 2008 GLCM texture features Calculates texture features from the input GLCMs Author: Avinash Uppuluri glcm, texture features 217 38
  • 3.875
3.9 | 8 ratings
Comments and Ratings by Avinash View all
Updated File Comments Rating
04 Feb 2013 GLCM_Features4.m: Vectorized version of GLCM_Features1.m [With code changes] GLCM_Features4 - Calculates the texture features from the different GLCMs Author: Avinash Uppuluri

Hi Ivana,

To clarify please run this script:
A = repmat(0:255, 256, 1);
[GLCM2, B] = graycomatrix(A,'Offset',[1 0],'G',[0,255]);
figure;plot(A(:), B(:), '*');
figure;imagesc(A);colorbar
figure;imagesc(B);colorbar

What this does is generates a 256 x 256 image that contains gray levels from 0 to 255 in all rows. Then I plot the input versus output plot. Hopefully this will clarify any doubts on the GLCM outputs levels. You probably have already gone through the definitions of 'GrayLimits' and 'NumLevels' which are the parameters that control the output levels.

'GrayLimits'

Two-element vector, [low high], that specifies how the grayscale values in I are linearly scaled into gray levels. Grayscale values less than or equal to low are scaled to 1. Grayscale values greater than or equal tohigh are scaled to NumLevels. If graylimits is set to [], graycomatrix uses the minimum and maximum grayscale values in the image as limits,[min(I(:)) max(I(:))].

Minimum and maximum specified by class, e.g.
double [0 1]
int16[-32768 32767]

'NumLevels'

Integer specifying the number of gray-levels to use when scaling the grayscale values in I. For example, if NumLevels is 8, graycomatrix scales the values in I so they are integers between 1 and 8. The number of gray-levels determines the size of the gray-level co-occurrence matrix (glcm).

8 (numeric)
2 (binary)

Hope this helps.
Avinash

17 Apr 2012 GLCM texture features Calculates texture features from the input GLCMs Author: Avinash Uppuluri

Hi Stephanie,

The number of sets of outputs will depend on the number of GLCMs input into the function for both graycoprops() and GLCM_features().

In using GLCM_features() please note the function of the 'pairs' flag as explained in the intro. Also make sure how your version of graycomatrix() works with regards to the 'Symmetric' flag.

"Haralick uses 'Symmetric' = true in computing the glcm. There is no Symmetric flag in the Matlab version I use hence I add the diagonally opposite pairs to obtain the Haralick glcm. Here it is assumed that the diagonally opposite orientations are paired one after the other in the matrix. If the above assumption is true with respect to the input glcm then setting the flag 'pairs' to 1 will compute the final glcms that would result by setting 'Symmetric' to true. If your glcm is computed using the
Matlab version with 'Symmetric' flag you can set the flag 'pairs' to 0".

Please do get back if there is still an issue.

Thanks

29 Mar 2012 Confusion matrix / Matching matrix along with Precision, Sensitivity, Specificity and Model Accuracy CFMATRIX2 calculates the confusion matrix and related parameters for a classification algo. Author: Avinash Uppuluri

Hi Atam,

Sorry about the delay in response but I have uploaded code to calculate the Precision(class), Sensitivity(class), Specificity(class) and the overall accuracy of model ( along with TP, TN, FN, FP) from the confusion matrix.

Thanks

29 Mar 2012 GLCM texture features Calculates texture features from the input GLCMs Author: Avinash Uppuluri

Hi Ujwala,

"I am working on MRI of brain for my Ph.D. now I am using your GLCM_Features4 program for feature extraction, but I can not understant this GLCM_Features4 program calculate 22 feature or 44 feature."

The output is a structure called 'out' which has 22 features for each of the GLCMs that are input. The function takes multiple GLCMs as input. Please go through the description for the program and let me know if further explanation is needed.

"when I was passing MRI img to this it will give 2 values that belong to 22 feature or 44. like contrast = 22.22 33.33. tell me this is 2 diff feature or same only for contrast."

Please note that the function does NOT take images as input rather it takes GLCMS ( calculated using a function like graycomatrix() ) as input. And depending on the number of GLCMs there are so main sets of 22 features. So for n GLCMs you will have n sets of 22 features as output.

Hope that helps.

28 Mar 2012 GLCM texture features Calculates texture features from the input GLCMs Author: Avinash Uppuluri

Hi Gomathi,

"to this GLCM program, I gave the tumor segmented image as input. Was I correct?"

Please make sure that you are giving the GLCM(s) as input to the GLCM_Features function. ( You can use help graycomatrix to know more on how to input your image into this matlab function ).

Please go through the initial description on this page and in the code and if there is still a problem please do get back.

Thanks!

Comments and Ratings on Avinash's Files View all
Updated File Comment by Comments Rating
17 Mar 2014 GLCM texture features Calculates texture features from the input GLCMs Author: Avinash Uppuluri parvin, Shaila

This code shows me the error:

>> GLCM_Features1
Error using GLCM_Features1 (line 118)
Too many or too few input arguments. Enter
GLCM and pairs.

>>

How to solve it?

I like it.

16 Dec 2013 GLCM_Features4.m: Vectorized version of GLCM_Features1.m [With code changes] GLCM_Features4 - Calculates the texture features from the different GLCMs Author: Avinash Uppuluri Prabhakar

GLCM2 = graycomatrix(I,'Offset',[2 0;0 2]); can explain about [2 0;0 2]

16 Dec 2013 GLCM_Features4.m: Vectorized version of GLCM_Features1.m [With code changes] GLCM_Features4 - Calculates the texture features from the different GLCMs Author: Avinash Uppuluri Prabhakar

Dear Avinash Uppuluri
1.SGLD matrix and this GLCM matrix both are same?

2.Here which direction (0,45,90,135) you preferred because i did,'t find exact offset value

17 Sep 2013 GLCM_Features4.m: Vectorized version of GLCM_Features1.m [With code changes] GLCM_Features4 - Calculates the texture features from the different GLCMs Author: Avinash Uppuluri abdulaziz, hamed

Dear Sir;

I used your GLCM_Features4 code for bitmap image but my MATLAB displayed this error message :

??? Undefined function or method 'GLCM_features4' for input
arguments of type 'double'.

Error in ==> call_glcm4 at 4
stats = GLCM_features4(GLCM2,0);

could you help me please?
I'll wait your answer impatiently
Best regards,
Hamed

01 Apr 2013 GLCM texture features Calculates texture features from the input GLCMs Author: Avinash Uppuluri subbmdee

Hi,
I am trying to extract these features for different region of interests(ROIs) of size 32x32 from different images, but I am getting same(wrong) value for particular feature. If I extract these features for the whole image, then the values are different(right) for different images.
Please help
thanks

Contact us