Uploading old snapshots and resizing.

I have been playing with uploading snapshots taken in Second Life and saved to disk. The information concerning how sl treats textures in this forum has been invaluable. I was looking at some old snapshots I took a while ago and saved in sl. I downloaded them to my computer (thank you forum search) and they are .tga files 512 X 512.

My thinking was that the original image was a rectangular screen shot that sl then takes and saves as a 512 X 512 square. I presume that the aspect ratio (?) was changed by sl when it converted the rectangle to a square. Thinking along those lines I resized one of the old snapshots I downloaded back to what I believe was the screen shot dimensions of 1024 X 768. The resulting image looks correct from a proportions point of view but all the clarity in the 512 X 512 picture appears lost on resizing. My hope was the clarity would remain. Maybe my logic or understanding of sl is incorrect. Any advice would be appreciated.

I am sure somewhere in the depths of the forums someone has asked this before but my early morning searching has not been helpful.

P.S. I just rezed a square and rezed a rectangle (1024 X 76 over it and took a snapshot. The snapshot does compress the image, the square is not and the rectangle looks like a square.

You'll get the best quality if you upload files that are 512x512 or some combination of powers of 2:
64, 128, 256, 512 or 1024.

Put your photo on the face of a prim and stretch the prim so you get your original aspect ration.

Just keep the original snapshot as 512 x 512, and apply it to a prim that has an aspect ratio similar to your screen at the time (like a 1.4 to 1 width vs height aspect ratio). The picture will look as good as it ever will that way.

What SL does with snapshots is take whatever was on screen at that moment and re-size it to a square 512 x 512 texture. So if you want a distortion-free in-world snapshot, re-size your viewer window to be square before you start snapping pictures.

If you're planning to save to disk, it doesn't matter what your window size is, as it preserves the aspect ratio, unless you tell it in the snapshot UI to do otherwise.

Somewhere in your preferrences (I think) there an option to take high resolution snapshots to disk. If the original snapshot was saved at 512 x 512 when you took them then resizing them to 1024 x 768 is almost doubling the size which will noticably effect the quality of the image.........the snapshot just does not have enough pixels to have the same clarity at that size.

On uploading what Sylvia said works. There's a couple other ways too and it's a toss up about which is better. You can resize your limage yourself instead of letting SL do if for you. It's best (in my experience) to resize the smaller dimension to equal the larger then size both dimensions to one of the powers of 2 mentioned. For your 1024 x 768 resolution that would mean upsizing the 768 to 1024. But you will loose a little clarity by introducing an additional 256 pixels on the vertical dimension (that are intrepulated by your imaging program) but at least you have control. SL will resize to 1024 x 512 if you let it do it for you. When you place your picture on a prim and size to your 1024 x 768 aspect ratio you can compensate for the lost pixels you introduced in your imaging software since you will be reducing the sides where you lost the pixels instead of aggrevating the situation by stretching that side yet again (if you allow SL to resize for you).

Another way is to not resize your snapshot at all but instead use background fill at the top and bottom of a 1024 x 1024 image size. Then when placed on a prim of the same aspect ratio use offsets and repeats to move the canvas fill off the viewable image. Both stretching a prim and repeats/offsets introduce a loss of clarity but not many can see the difference so either of the three ways will work fine. My method is to resize my snapshots to a 1024 x 1024 image then resize down to get my aspect ratio back once placed on a prim.

Thank you all for the input, much appreciated. Just as an FYI, I built a square in sl and went so far as to measure it using a ruler on my screen to be sure I was looking at it square on. I took a snapshot and then measured the snapshot of the square with the ruler.
Bottom line is I came out with a factor of 1.431034, which is just what Ceera suggested above. Lesson learned, I always save any shots to disk first then upload them later.