Tips for Making Cards Look Nice and Straight?

I’m really thinking about doing a VASSAL module (for a game I have that takes up a lot of table space), but I am daunted because I’ve never done it before and it seems like a lot of work. So far, I’ve made scans of the cards, and I figured that would be the most tedious part, but then I realized that I’d have to take those scans and turn them into individual image files for each card. And for the module to look “real,” each of these files would theoretically be depicting a perfectly straight card with no borders or white space around the card, even though that’s obviously not how they came out just from the scans. I’m pretty familiar with the basics of GIMP, so I know how to rotate images and stuff like that, but I’d like to know if there are any time-saving tricks to decrease the tedium of minutely rotating each card until it appears to be pretty much straight, and then erasing the white space (by hand, to some extent), carefully, to make sure I don’t erase any of the actual card.

I figure anyone who’s made a module from any kind of card-heavy game must have developed some good tips and time-savers for this sort of thing.

What I do is once I scanned the cards, I use a graphics program (there are many online you can download for free) and crop the cards. By using a grid in the graphics program you can make the cards straight and all the same size. Also, if you want to make the cards round you will need to learn (did this by trial and error) how to use transparency.

I guess your cards are hand drawn (and not computer generated) since you have to scan them…
Anyway, if you want, I have a bash script (for Linux, might work on Mac) to automatically cut an image into tiny rectangular parts along a grid, which I use for cutting images from a counters sheet or a cards sheet. It needs the cards/counters to be perfectly straight because it’s cutting along vertical and horizontal lines only.
Here it is. You’ll probably have to do some trial and errors with the variables defined at start to find the correct values.


width and height of each sub-image

cards : 250x350

counters : 44x44 + convert -frame 1x1+1+0


offset of the top left corner of the images

counters : 28,41


space between image. Usefull to remove border from counters

counters : 50x50


for page in 1 ; do
xoff=expr $xinit + $page \* 550;
for bloc in 4 ; do
yoff=expr $yinit + $bloc \* 112 + $bloc / 2;
for col in 4 ; do
for lig in 0; do
convert -crop ${width}x$height+expr $xoff + $xspace \* $col+expr $yoff + $yspace \* $lig +repage $1 ${1%.png}-$page-$bloc-$col-$lig.png ;

On a related tangent, can one design a “hand” of cards so they look like a fan, “close to your chest poker”-style?

I scanned all of my cards, nine at a time, then started to use the gimp to crop and straighten them. However, I switched to using Fred’s Multicrop and Imagemagick:

The multicrop script separates, straightens, and crops just about any set of images that don’t overlap or touch the edge of the scan, provided there’s a similar background around them. It spit out over a thousand usable images from 116 pages of scans in one night with minimal effort.

In my case, I wanted the cards cropped a little closer, the background removed at the rounded corners, and the whole thing resized (from 600 dpi), so I wrote a small script to use imagemagick to take the edges off. It’s kind of iffy, but it worked in most cases, and I did the remainder manually. I’ll post it if anyone is interested.