Two devices, similar densities yet different image sizes?

Question

Ok here is a problem that is puzzelling me that I really would like you to help me out with. I am testing my app with both HTC amaze and Galaxy S2 (as I know both are High densi

Answer 1

The answer is in the numbers right in front of you.

Source http://www.androidauthority.com/htc-amaze-4g-vs-samsung-galaxy-s-ii-t-mobile-27110/

In terms of screen size, the Samsung Galaxy S2 has a slightly larger screen with 4.52 inches of display. The HTC Amaze 4G, on the other hand, comes with a screen similar in size to the international variant of the Galaxy S2–4.3 inches.

The HTC Amaze has a higher resolution, and a smaller physical screen. This results in a higher pixel density- that means smaller physical pixels, because a larger number of them needs to be crammed into a tighter place.

An image of for example 240x160 would therefore appear smaller on the Amaze.

The reported DPI values for the S2 is clearly wrong. According to the metrics given it is ' 800/ 160 = 5 inches on the long side, and 480/160 = 3 inches on the short side. This would have given a screen size of sqrt (5 * 5 + 3*3 ) = 5,8 inches.

The DPI values for The amaze is correct. As we see if we do a simple pythagoras. Sqrt (960/258^2 + 540/256^2) = 4,27"

As a developer I experience the same thing when moving from my test device HTC sensation, and the S2.