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Image Intensity

Asked by M@lik Ali

M@lik Ali (view profile)

on 4 Jun 2012
Latest activity Commented on by Image Analyst

Image Analyst (view profile)

on 11 Feb 2014

Hi all, Can any one tel me the command in matlab to calculate the intensity of image.

2 Comments

Jean

Jean (view profile)

on 5 Jul 2013

Does anyone further know how to do this for a specific area of pixels? For example, image(100:1:200,100:1:200) for a 100 by 100 pixel area, and get the intensity in this area as an average?

Image Analyst

Image Analyst (view profile)

on 5 Jul 2013
meanGrayLevel = mean2(yourImage(100:200,100:200));

Don't use "image" as the name of your variable since it's a function.

M@lik Ali

M@lik Ali (view profile)

Tags

3 Answers

Answer by Image Analyst

Image Analyst (view profile)

on 4 Jun 2012
Accepted answer

The mean of a particular pixel is just simply the pixel value, since there is only one sample - nothing really to take the mean of:

intensityValue = grayImage(100, 230); 
meanIntensityValue = mean(grayImage(100, 230)); 

Here, of course meanIntensityValue will equal intensityValue.

To get the mean of all the pixel values in the entire image, you can do any of these:

meanIntensityValue = mean2(grayImage);
meanIntensityValue = mean(grayImage(:));
meanIntensityValue = mean(mean(grayImage));

7 Comments

Iain

Iain (view profile)

on 25 Jun 2013

Yes. Both should work. (Though, you have a spare "=" in the first one).

Mona

Mona (view profile)

on 26 Jun 2013

Thank you so much

Image Analyst

Image Analyst (view profile)

on 26 Jun 2013

Please mark the discussion as "Answered" if you're done with it. Unless you want to open a can of confusing worms about how the units of an image are not really intensity.

Image Analyst

Image Analyst (view profile)

Answer by Adina Stoica

Adina Stoica (view profile)

on 4 Jun 2012

Well, the intensity of the image is the average of the intensities of all pixels in an image (unless you're doing anything more specific than that). So if you do

mean(imagefile(:))

you should get the intensity of the image.

1 Comment

M@lik Ali

M@lik Ali (view profile)

on 4 Jun 2012

Adina thanks for your response,

But actually i want to calculate the intensity value of all elements of the images.

someone told me like

intensityValue = grayImage(100, 230);

But in i have to calculate the intensity value of each pixel or total image, i think i can do it by calculating the intensity of each pixel and then add it but i am not sure.

Kindly help me about it..

Adina Stoica

Adina Stoica (view profile)

Answer by Saranya

Saranya (view profile)

on 30 Jan 2014

hi image analyst i want to measure the intensity profile for gray scale image.. can you help me..?

10 Comments

Image Analyst

Image Analyst (view profile)

on 3 Feb 2014

Yes. improfile() can take arguments that are the endpoints of the line.

Jensa

Jensa (view profile)

on 11 Feb 2014

Hi Image Analyst...Can you help me to find the density profile for my chromosome image..Attaching the image along with this.. http://postimg.org/image/pe5ozahzb/e770bd0c/

Image Analyst

Image Analyst (view profile)

on 11 Feb 2014

Please start your own discusssion.

Saranya

Saranya (view profile)

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