# Re: Blurring an image?

**URL:** <https://psychtoolbox.discourse.group/t/re-blurring-an-image/1814>\
**Category:** Uncategorized\
**Created:** [February 10, 2002, 10:38pm UTC](https://psychtoolbox.discourse.group/t/re-blurring-an-image/1814 "2002-02-10T22:38:45Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![denispelli](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@denispelli](https://psychtoolbox.discourse.group/u/denispelli)\
**Post date:** [February 10, 2002, 10:38pm UTC](https://psychtoolbox.discourse.group/t/re-blurring-an-image/1814/1 "2002-02-10T22:38:45Z")

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> \>Professor Pelli,  
> \>  
> \>I'm one of your fans of your website --- psychophysicaltoolbox.You are so   
> \>kind to contribute your works and provide the toolbox. I really learn a   
> \>lot from the website.  
> \>  
> \>I'm a self-learner in Matlab with limited knowledge in programing. May I   
> \>ask you a question about blurring an image? I found a problem in my work,   
> \>when I created some blurred images with the following codes:  
> \>Img=imread(I.tif');  
> \>G=rgb2gray(s);  
> \>n=double(G)/255;  
> \>f=[1/16 2/16 1/16; 2/16 4/16 2/16; 1/16 2/16 1/16];  
> \>C=conv2(n,f,'same');  
> \>  
> \>I found that the degree of blur is too significant. How can I blur images   
> \>with just-noticeable-difference?   
> \>  
> \>  
> \>  
> \>Thank you for your kind attention.  
> \>  
> \>  
> \>Best Regards,  
> \>Michelle

dear michelle  
  
you're doing what i'd do, but others in the forum may have useful   
suggestions, so i'm forwarding your query there.  
[http://yahoogroups.com/group/psychtoolbox/](http://yahoogroups.com/group/psychtoolbox/)  
  
you could also low-pass filter using the 2d fft.   
  
best  
  
denis  
  
  
NOTE TO ALL: [denis.pelli@...](mailto:denis.pelli@...) is my preferred email address. Please   
use that address. My "verizon.net" address will go away soon, partly   
because Verizon forces me to use that as my "From:" address. My current   
email program won't allow me to designate a separate "Reply-to:" address.