# Revision history [back]

### Calc Grain of Image? (Difference between two Pictures)

Hi There,

I am now working nearly 1 Months with the iOS Library of OpenCV and I got to a point where I need your help!

Here are two Examples of the Images I am currently scanning with the Camera of the iPhone.

This is the Image that should be nearly 0% Percent, Maybe somewhere 10%.

This Image should be somewhere near 100% Percent.

Problem: I now have to calculate a value to get a difference between the two of them. I tried working over threshold and mean but the Problem is the Camera of the iPhone. The values/colors are somehow different each time I try to make a scanning try.

Because the solution has to be somewhere legit, there can not be a way different result each time I scan the circle.

Question: So I thought i would be perfect to somehow calculate the grain of the image? Because the Image of nearly 100% is way more granulated than 0%. And so the Color of the Image would not be that important. Or is this the wrong way?

Hope you can help me! :) Thanks!

### Calc Grain of Image? (Difference between two Pictures)

Hi There,

I am now working nearly 1 Months with the iOS Library of OpenCV and I got to a point where I need your help!

Here are two Examples of the Images I am currently scanning with the Camera of the iPhone.

This is the Image that should be nearly 0% Percent, Maybe somewhere 10%.

This Image should be somewhere near 100% Percent.

Problem: I now have to calculate a value to get a difference between the two of them. I tried working over threshold and mean but the Problem is the Camera of the iPhone. The values/colors are somehow different each time I try to make a scanning try.

Because the solution has to be somewhere legit, there can not be a way different result each time I scan the circle.

Question: So I thought i would be perfect to somehow calculate the grain of the image? Because the Image of nearly 100% is way more granulated than 0%. And so the Color of the Image would not be that important. Or is this the wrong way?

Hope you can help me! :) Thanks!

### Calc Grain of Image? (Difference between two Pictures)

Hi There,

I am now working nearly 1 Months with the iOS Library of OpenCV and I got to a point where I need your help!

Here are two Examples of the Images I am currently scanning with the Camera of the iPhone.

This is the Image that should be nearly 0% Percent, Maybe somewhere 10%.

This Image should be somewhere near 100% Percent.

Problem: I now have to calculate a value to get a difference between the two of them. I tried working over threshold and mean but the Problem is the Camera of the iPhone. The values/colors are somehow different each time I try to make a scanning try.

Because the solution has to be somewhere legit, there can not be a way different result each time I scan the circle.

Question: So I thought i would be perfect to somehow calculate the grain of the image? Because the Image of nearly 100% is way more granulated than 0%. And so the Color of the Image would not be that important. Or is this the wrong way?

Hope you can help me! :) Thanks!

EDIT: 50% Image