How to know if there is different information in an image (large gap between pixels )

Hi All

I have group of image which of the following features tell me that there are changes in information happened in the image (i.e there is a large gap between pixels )? :

Entropy? ,dissimilarity ,...etc ?

I need an indication if the ROI edges(borders)diffire than remaining image

[Walter Roberson]

What kind of output device are you using such that the pixels are not adjacent to each other? Perhaps you are asking about pixels whose values have particular properties?

When you are talking about "changes in information happened in the image", are you referring to comparing one image to another, or are you talking about pattern changes within a single image, such as if a pattern of circles turned into a pattern of rectangles in a different part of the image ?

[Image Analyst]

Why would there be gap between pixels? Pixels have to be in a rectangular matrix - all touching one another, unless you're referring to just some pixels that have certain properties, like they're brighter than some specified amount. Please attach as many images as you need to illustrate your question.

[Walter Roberson]

In the old Sony Trinitron color "stripe" phosphor, the pixels had a mask between them and so could be said to not be touching. Likewise in many LCD designs, pixels have a physical mask around them, rather than the color areas being completely contiguous.

Those scrolling-light displays are another example of pixels that have a gap between them.

When doing printing to wire meshes (e.g., display signs that go on bus windows but which can be looked out of) then there may be gaps between pixels, and one needs to take that into account when planning the graphics.

So it is possible. But in any such case that I can think of, information about the gap between pixels is something that you would have to have given as input, not something you would calculate.