First ScrapWalls Collage (~950 photos)
Collages are cool. Everybody knows that. Unfortunately, making a collage can take hours or even days. I learned this first-hand when building a 900-photo collage for an anniversary present (see image to the right). It took eight hours just to place the images. After spending all this time, I began to wonder: is there a better way to build a collage? This is the story of ScrapWalls and our automated collage software.
shapecollage.com heart collage
As it turns out, there are a few options for automatically building collages on the Internet. Most of them are not very good. The bad ones will crop your photos and insert them into fixed slots. Snapfish is slightly better; it lets you make rectangular collages with up to 30 photos. However, this won’t cut it for large projects. The best option for handling a lot of photos is Shape Collage (www.shapecollage.com – see right). Unfortunately, you need a lot of pictures to recognize the shape at the end. Also, half of your photos will end up mostly cropped, leaving lots of cut-off heads and left-out people – less than ideal for an anniversary present!
City Collage – Original Algorithm
In December 2007, some friends and I began making ScrapWalls with the goal of helping people build better collages. Our initial launch of ScrapWalls in early 2008 supported manual photo placement. This got us talking to District Photo (the company that does printing for Snapfish, Wal Mart, Walgreen’s, and many others). They saw some of the shape collages and asked if we could design software that builds them automatically. The response was short: “We’ll try…”
Nature Collage – New Algorithm
The first iteration was very rough. We started by constructing shapes out of primitive “line” and “point” objects. The idea was to build a shape from rectangles of fixed size, and then insert images into the rectangles until they were full, adding padding to fill the rectangle. An example of a “city” shape using this original algorithm can be seen on the right.
As you can see, the first shape collage algorithm was far from perfect. The shape edges are jagged and the photos have uneven gaps. Because the shapes were made of fixed rectangles, they also needed a lot of photos, but could not have too many. We showed the initial prototype to District Photo, and they came up with an idea that helped solve all of these problems: shape masks. Instead of expanding the photos to cover the shape, just add extra images around the edge and crop them using the mask. Masks also make a well-defined shape with only a handful of photos. (It would be hard to make a “heart” with only 4 rectangular images!) The result of version 2.0 can be seen to the right. Things were starting to look much better!
Collage With Image Placement
ScrapWalls User Collage
The story is almost over, but not before one final suggestion from District Photo: “Can you support photo placement?” This is a very simple question with a very difficult answer. Letting people place a photo seems easy, but what do you do with the other pictures? What if they overlap? What if there are gaps? In the interest of brevity, I will keep it short. If you want more detail, we will be posting a link to our recent patent submission on building shape collages shortly. Remember the rectangular “lines” that covered the shape? They are still there, but need to be chopped up to make room for the placed photo. The first step is stretching and shrinking the lines that are parallel but partially overlap the placed image so that they become adjacent. Then you have remaining rectangles that the placed photos is fully bisecting. These must be cut into two rectangles with a gap for the placed image in between. Now the photo is in its final location, and there are no gaps or overlapping images! This can be repeated several times to achieve the final result. An example with wedding photos can be seen on the right.
Since adding shape collages to ScrapWalls in August 2010, thousands of people have made collages. We are surprised every day by the creativity of our users. The possibilities are endless with shapes and photo placement, but one that stands out can be seen on the right. The creator used placement to put the main photo in the center of the collage. She was also kind enough to let us display her collage publicly on our site. Creating shape collage software has been an adventure. We hope that you have as much fun using our site as we did making it!