If you are going through the process of digitizing your traditional paintings, you have undoubtedly noticed that not all of your artwork fits onto the standard 8.5″x11.7″ glass of your flatbed scanner. Have no fear! With a few minor Photoshop tips, stitching together your large paintings doesn’t have to be such a hassle.
To get a great scan of your painting, you should first go back and review some of my scanning tips that I have already posted. Most importantly, just remember to lay your painting as flat as possible on the scanner in order to minimize how much you have to fix later.
1. Get organized.
After you have successfully scanned in your entire painting, open all the images in Photoshop and organize them. Rotate them all so they are all straight and right-side-up. Then, lay them all out on your screen so you can see how they fit together.
Take the piece that is in the upper-left corner of the painting. Expand the canvas size so that it is big enough to hold all of your pieces. Since my painting consists of six pieces, three across and two down, I expanded my canvas by 300% width-wise, and 200% by height. Anchor the image into the upper-left corner.
Click and drag or copy/paste the rest of your painting onto this new, large canvas. Each piece should end up on its own layer. Keep them roughly arranged in their correct location.
2. Line up your pieces.
Your next task will be to align the pieces together so that they fit properly. To do that, change the blending modes of all of the layers to “Multiply” so you can see through each piece. Take one piece at a time and line it up carefully. Use the arrow keys to gently nudge the pieces into place.
Change all your layer modes back to “Normal”, and you should see your painting starting to come together.
It obviously still needs more work though…
3. Erase the lines.
Select the Marquee tool. At the top of the screen, there is a “Feather” option. Enter 20 px or so here.
Hide all of your layers except for your first two pieces. Highlight part of the overlap between the two pieces. Delete your selection.
Repeat this process for each remaining piece. Sometimes, this is all you need to do in order to stitch together your painting. When I finished, however, I still had some ugly shadows on the edges of my pieces.
4. Make additional adjustments.
To fix the shadows still on my painting, I created a new Levels Adjustment Layer. Use the button at the bottom of the Layers palette. When the Levels window pops up, adjust the settings so that the painting is obviously lighter, then click okay.
Your Adjustment Layer should be highlighted in your Layers palette. Make sure your Foreground and Background colors are white and black, respectively. If they are not, press “D” on your keyboard. Now, press Command+Delete. The small white box in the Layers palette should now be filled completely with black, and the adjustments you just made will appear to have vanished.
Now, select the brush tool. Pick a soft round brush and lower the opacity to about 10% or so. With white still as your foreground color, gently brush over your dark edges. This will bring back some of your Levels adjustment you made earlier, making it lighter.
This should fix the shadows significantly. If you need to, you can adjust your levels settings by double clicking on the adjustment layer in the Layers palette.
When you have fixed your painting to your liking, go ahead and flatten the image. You can make further adjustments, such as brightness/contrast and hue/saturation if you need to. When you’re done, use the crop tool to get rid of the extra space on the canvas.
The finished scanned painting…