Open your photo in PSP. I chose one of the dog pics from the Rose Bowl Parade supplied by Eagle. The original is rather large, and would make too large a tube for most images, but if it is left large, it does seem to make it easier to tube, plus will help to hide any little mistakes. I did crop this picture and reduced it by half, and the image for the tube is still of good size.
Go to layers, and left click on Promote Background Layer. This changes it to a raster layer. Using the freehand or point to point selection, I next make a rough outline of what I want to tube. This gets rid of excess so I can tune in on the finer points.
I used an actual line to show approximately where my marching ants would be. It is easier to do the marching ants than the smooth line. Once your marching ants are in place, click on Selections, then on Invert. Next hit delete. This should clear your excess outside your image. Deselect.
I then copy my image and paste as a new layer onto a colored background so that I can see if I have missed any when I think I am finished. I used white for this one. Next I zoom my image to about 200-300%, and pick an area to start on. As you go around your image, get as close as you can, but don't worry if you still have a tiny edge. This can be taken care of with final touches.
I do parts at a time on large images. It is easier to control the lines. Once I have an area selected, I then hit delete to clear the area. I continue to do this until all the surrounding area is clear.
I have finished with my basic clearing, now it is time to do final touches. Even with this dog being made of flowers, it still was fairly easy to trim. Final touches - zoom to about 200-300%, then either use the point to point freehand selection, or put your eraser on size 1-2, with the hardness, density and opacity to 100 and clear your small areas.
Once all your areas are clear, and it looks ok on your colored background, either delete your background layer or copy and paste your image as a new image - and now you can export as a tube. The image must be on a single raster layer to be able to export. My image would be too large - about height of 380, so I am going to reduce it in size prior to exporting as a tube.
These steps are very basic and will work for most images; however, some images are more intricate and have many small areas to clean around. You can try varied backgrounds to do your checking, and then you can also use some other methods to help with the clearing. If you are having problems getting your tubes as clean as you would like, please post a question here at thePlace. There is always someone who can help!!