# Are there any good "conceptual distances" for comparing two images?

I want to define some distances to use over an image, which I create.

I think I need to define two different "distances".

1. The first distance should be the most robustness preserving in compare to the original image.

2. The second one should would be the most transparency preserving in compare to the
original image.

## For example:

Let $I_1, I_2$ and $I_3$ be images, $I_1$ is the original and $I_2, I_3$ are some similar images:

I would like to define a metric or some distance so a and b will holds:

a. $|I1 -I2| > |I_1 -I_3| <=> I_2$ is more robustness preserving then $I_3$ in compare to
the origin $I_1$.

b. $|I_1 -I_2| > |I_1 -I_3| <=> I_2$ is more transparency preserving then $I_3$ in compare to the origin $I_1$.

as I said the distance in a. and b. don't have to be the same at all.

I saw this post but it didn't help me alot, it may help you to find a good answer:

What distance metric can I use for comparing images?

• Image processing isn't my thing, so maybe I'm just ignorant of the terms, but can you define "robustness-preserved" and "transparency-preserved?" Jan 19, 2012 at 15:19