MobileRead Forums - View Single Post - PRS-950 Proper Sizing for 950 Wallpapers = 800 X 480 (or any other 5:3 ratio)

tommylander · 01-01-2011, 02:54 PM

I thought I'd post this in case anybody else was having trouble getting their screen wallpaper images to show up properly in standby on the 950.

I was using 800 X 600 images (like on the 650) at first, but then I realized the pictures were getting stretched out on standby and not coming out the way I wanted them to.

So I tried to find the proper sizing for the larger 950 screen and couldn't find anything, and then I had a flashback to geometry class and decided to try to figure it out myself.

Namely, I remembered the Pythagorean Theorem for right triangles: a2 (squared) + b2 = c2.

And I knew the 650 screen fit images with the ratio 800 X 600, and also the screen measured 6 inches if you drew a diagonal line from one corner to the other.

So I used the info to come up with these equations:

1) a2 + b2 = 36 (6 squared)

2) a = 3b/4 (b is the longer vertical side of the screen; 600/800=3/4)

Then using replacement, I came up with this:

(3b/4)2 + b2 = 36.

--> 9b2/16 + b2 = 36

--> 9b2/16 = 36 - b2

--> 9b2 = 576 - 16b2

--> 25b2 = 576

--> b2 = 23 (I rounded off a tiny bit here)

Going back to the original a2 + b2 = 36, I could now calculate that a2 = the square root of 13, which comes out to be almost exactly 3.6.

This gives me the length of the shorter horizontal length of the 650 screen, which is equal to the horizontal length of the 950 screen. Now I had to use this info to get the length of the longer vertical length of the 950 screen:

(3.6)2 + b2 = 49 (as the diagonal length of the 950 screen is 7 inches, not 6)

--> 13 + b2 = 49

--> b2 = 36

--> b = 6

Now I knew that the dimensions of the 950 screen was 6 inches (vertical) by 3.6 inches (horizontal). Voila, that gave me a 5:3 ratio for the two lengths, which meant that any wallpaper images for the 950 screen also needed to have the same 5:3 ratio, as in 800X480 or 1000X600.

So I resized and cropped my wallpaper images to fit the 5:3 dimensions, and they now work perfectly.

Anyhow, I wanted to post this geeky thread to show that some things you learned in school DO end up being useful in adulthood

01-01-2011, 02:54 PM	#1
tommylander Junior Member Posts: 7 Karma: 110 Join Date: Dec 2010 Device: Sony PRS-950	Proper Sizing for 950 Wallpapers = 800 X 480 (or any other 5:3 ratio) I thought I'd post this in case anybody else was having trouble getting their screen wallpaper images to show up properly in standby on the 950. I was using 800 X 600 images (like on the 650) at first, but then I realized the pictures were getting stretched out on standby and not coming out the way I wanted them to. So I tried to find the proper sizing for the larger 950 screen and couldn't find anything, and then I had a flashback to geometry class and decided to try to figure it out myself. Namely, I remembered the Pythagorean Theorem for right triangles: a2 (squared) + b2 = c2. And I knew the 650 screen fit images with the ratio 800 X 600, and also the screen measured 6 inches if you drew a diagonal line from one corner to the other. So I used the info to come up with these equations: 1) a2 + b2 = 36 (6 squared) 2) a = 3b/4 (b is the longer vertical side of the screen; 600/800=3/4) Then using replacement, I came up with this: (3b/4)2 + b2 = 36. --> 9b2/16 + b2 = 36 --> 9b2/16 = 36 - b2 --> 9b2 = 576 - 16b2 --> 25b2 = 576 --> b2 = 23 (I rounded off a tiny bit here) Going back to the original a2 + b2 = 36, I could now calculate that a2 = the square root of 13, which comes out to be almost exactly 3.6. This gives me the length of the shorter horizontal length of the 650 screen, which is equal to the horizontal length of the 950 screen. Now I had to use this info to get the length of the longer vertical length of the 950 screen: (3.6)2 + b2 = 49 (as the diagonal length of the 950 screen is 7 inches, not 6) --> 13 + b2 = 49 --> b2 = 36 --> b = 6 Now I knew that the dimensions of the 950 screen was 6 inches (vertical) by 3.6 inches (horizontal). Voila, that gave me a 5:3 ratio for the two lengths, which meant that any wallpaper images for the 950 screen also needed to have the same 5:3 ratio, as in 800X480 or 1000X600. So I resized and cropped my wallpaper images to fit the 5:3 dimensions, and they now work perfectly. Anyhow, I wanted to post this geeky thread to show that some things you learned in school DO end up being useful in adulthood