I've been using Paint Shop Pro from JASC Software, Inc. for about ten years. I have version 6.01 and am probably five years or so out of date. To be honest, if I could make the 1995 version run on a Windows 98 system, I'd probably still use that old version. I just tend to like the older ones better. When I started buying Paint Shop Pro, the cost was about $70 as compared to the $300 that Adobe wanted for Photoshop or Corel wanted for whatever they have. I don't know the relative costs today, but Paint Shop Pro has traditionally been the lower cost program that does everything that the more expensive programs do.
I'm shooting with an Olympus C-740 digital camera, and sometimes the camera is as much a problem as the software used to work on the image. Can you tell me what camera you use? Do you have it set so that it chooses where to focus or can you choose where to focus?
When I look at the picture at full size in the gallery, it is 1200 x 1000 pixels. The snakes appear a little blurry to me, and the camera seems to have focused on the pot in the background instead of the snakes. A good camera should take a reasonably good picture for our purposes at 1200 x 1000 pixels. My first thought is that resizing isn't the big issue here.
If you get Paint Shop Pro, resizing is fairly easy. I always look at the picture to see whether I need to crop. If so, I use the selector from the tool bar to define the area to be cropped. I then click the commands to do the cropping. I then look at the picture on my screen and check the magnification of the display window. If the picture looks pretty good, I just use the resize command to make the final picture about the size that I'm viewing. For instance, if the photo looks okay but is displayed at 1:4, then I'll do a resize to about 25% so that 1:1 looks similar. I try not to upload anything that's going to be much bigger than 800 x 600 because bigger photos are a pain for folks who like to have a screen resolution of 800 x 600.
The photo that I've posted here started at 2048 x 1536 and was not cropped at all. I resized it to 614 x 461. The detail obviously won't be as good at the lower resolution, but the photo is still pretty clear. If I were shooting my old 35 mm camera, I could use polarizing filters to eliminate the reflection in the glass. Someday, I need to get a digital SLR so that I can use real lenses and real filters instead of what comes on the standard digital camera.
This stuff is hard to explain in a note of this kind, so I probably haven't helped you much. Cutting to the summary, I use Paint Shop Pro and recommend it.
Good luck,
Bill

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It's not how many snakes you have. It's how happy and healthy you can keep them.