I was going to upload something to the SHP FB group, but it would not let me add the attachment.
There was an old program on the King's Quest VI CD that played a slideshow of the beautifully hand painted background artwork from the game. Unfortunately, this program was 16-bit and as such will not play on modern x64 systems. In addition it used an outdated Indeo encoded AVI to store the images. I have extracted all of the images from it and wrote a new program to recreate this KQ6 slide show program. It allows you play the slide show or to step through the images one-by-one. You can also save any of the images you wish or even set any as your wallpaper.
The images are what I extracted from the old AVI. I only converted to RGB true color. I thought about upscaling them precisely because of the wallpaper ability. This could easily be done, but would take a lot of repetitive, tedious work and probably greatly increase the file size as all of the images are embedded in the EXE. Perhaps someday... when I have more time. *Sigh*
I've already upscaled all of them and added them to my shared Google Drive folder of ESRGAN upscaled images a couple years back. I'll get the link in a bit.
Looks like MI has you covered (he edited his post).
What do you guys use to upscale? Is it a program? Website? Can you do it with an image editor? What what be the ideal resolution for LSL2 / LSL3 images?
MI did his with ESRGAN. I only upscaled in Photopaint using a pixel perfect ratio. If you upscale a 320x200 image to 1600x1200 with no anti-aliasing it will give you nice even pixel blocks without having to resort to the likes of nearest neighbor or bicubic resampling and its unavoidable blurring or artifacting. If your photo editor can upscale without maintaining the original aspect ratio and no anti-aliasing you can do it, too.
OK, I broke down and upscaled the images and made a few alterations to the slide show viewer. I Tried MI's images, but the size was near 300MB. With the upscaled images I just did it increased the size to ~44MB.
Also, you could probably use Image Magick command line tools to batch upscale. Might make your life easier. That's what I did to the images in the "Classic Backgrounds (Unfiltered)" folder in my shared Drive link. (all except the KQ6 hi-res ones from the player)
I took his upgraded images from the game and did one of these for LSL7. Presenting the Leisure Suit Larry 7 High Res Art Player. Note this one is big. 196 MB, but these images are impressive.