Great for backgrounds, this linestretch effect is much easier to achieve in Animation Shop than Paint Shop Pro.
Open up the image you want to stretch in Animation Shop.
Make a new image with an opaque background the same wdith as your other image, but much bigger. For example, my original image is 282 x 212 (pixels), but I’m making my white one 282 x 450 pixels. Copy your original image and paste (into selected frame) on your white background. Paste it at the top like mine:
Go to Effects > Insert Image Effect, and where it says ‘Effect’ select ‘Stream’. Click Ok.
Go through your new frames and click the one that has the best lines. Copy and paste ‘as new animation’, then go to File > Save and save your image. If it’s a photo like mine, you might want to save it in Paint Shop Pro as a .jpg or .png rather than a .gif. Here’s my finished result: