Further on the topic of
hi-res menus etc., I've been playing around with various ideas using image resizing algorithms, and had placed some hope with the
xBRZ scaler. While the initial results weren't as good as I had expected, eventually I got a more or less decent resized image (
original image resized to 640x480 for comparison):
The steps to produce this were as follows:
1. I used the ScalerTest tool (available
here) to get the original image scaled to 2x its original size with xBRZ. Don't forget to untick the option to show scaler type in the image.
2. The output image was then corrected to 4:3 aspect ration in GIMP by first resizing it to 640x1200 with Nearest Neighbour, then to 640x480 with Sinc3 interpolation method.
3. The image was then converted to its original
Wolf3D palette, again using GIMP. For this, you need to import the palette from any
Wolf3D[ image (e.g. a screenshot taken in DOSBox). Load it, then open the
palettes dialog and import the palette from the screenshot. To then convert the modified upscaled image to the palette, select Image -> Mode ->
Indexed, select the desired palette from the list of custom palettes and untick the option to remove unused colours from the colourmap. Don't use any dithering.
The resulting image can be then touched up if needed (I didn't do anything for the above version). I think it's pretty decent overall.