Macenstein

The other day I came across a “tutorial” on how to make a photomosaic using Leopard’s cool new photomosaic screensaver. While the title sounded intriguing, unfortunately what it eventually boiled down to was “take a screenshot of the mosaic when it resolves”. Pretty lame. The resolution on such a screen grab would not be high-res enough to use for printing, and you’d have hardly any control over the final result. Assuming you actually liked the person you would be making the mosaic for, this could only end in disappointment.

To that end, I have a relatively cheap way to create a high quality photomosaic, suitable for framing and gift giving (in fact, the most expensive part will be the frame). From my experience, this is an especially popular gift amongst moms, and in fact I am making one this year for my sister-in-law, who I drew in our family Christmas grab bag (she never reads our site, so I should be safe).

Here’s what you’ll need:

1) The right software. Download the free application MacOSaiX 2.0. It would be nice if Apple incorporated Leopard’s photomosaic screensaver’s technology to iPhoto and allowed you to make mosaics directly from within, but they didn’t. Luckily, MacOSaiX does a great job of putting together a photomosaic from your photos, and offers a good deal of control.

2) A huge amount of photos. How good your final result looks depends on 2 things. First, your choice of target image (the image you want the mosaic to look like). Choosing an overly busy or complicated image often doesn’t look great when used for a photomosaic. In my experience, a shot of a person or pet that is easily identifiable, and composed to fill the frame works best. So for instance a nicely framed shot of a child’s face is always a good starting point.

Second, you’ll need a ton of photos from which to make the mosaic. Mathematically, if you are making a 20 picture by 30 picture mosaic, you would need 600 images (and thats assuming you had 600 “perfect matches”). I’d recommend at least 1000, but it can work well with less depending on the images and the size of your mosaic. I usually use around 5000-7000 or so. The larger the number of source images you have to chose from, the better matches the software will be able to come up with, giving you a better-looking result. The downside is, of course, the more images you have to choose from, the longer the mosaic will take to make as the software sifts through them.

Above: the more images you have, the better match MacOSaiX can make. Photomosaics look best from about 5 feet away.

Luckily for me, I am extremely anal, and have gone through the trouble of labeling all my photos in iPhoto with the names of the people in them. So, for instance if I wanted to make a photomosaic of my son, I could search for “Cooper”, and bring up “only” the 6000 images I have with him in them. I personally find it kind of cool to make the mosaic out of smaller shots of that person, if possible.

If you don’t have a ton of photos, don’t worry. MacOSaiX can actually grab images from other sources, such as Flickr or Google images, and can even pull images from video. So shooting 20 minutes of video footage at 30 frames per second can quickly give you a couple thousand images. If using video as a filler “cheat”, I recommend changing the locations and outfits of your subjects to add variety to the shots. For instance, if you are making a mosaic of your dog, shoot 1 minute of footage in your living room, outside on walk, the deck, the street, the beach, close ups, wide shots, etc..

3) (Optional) An image editor, like Photoshop, or some cheap/free alternative. While MacOSaiX produces great results, sometimes you need to do a little tweaking (ie “cheating” to get a really good final product).

4) A lot of time. MacOSaiX is SLOW (and will occasionally crash (although version 2 is much more stable than version 1), requiring you to start over. But hey, it’s free!)

Ready? Let’s begin.

Above: choose the right image. My brother hired a professional photographer to take shots of his daughter this summer, so I have a good target image.

Launch MacOSaiX. You will be asked to choose the target image you wish your mosaic to resemble. Next, you’ll be asked to choose your source directory. MacOSaix wants to use your pictures directory by default, but you can select that source and remove it. As I said, I labeled all my iPhoto photos, so I can search for “Cooper”, then either create a smart album in iPhoto or export all 6000 shots of him to a new temporary folder on my desktop. That way I know MacOSaiX will only using those images in building the mosaic. You can add multiple sources to pull from, such a s 3 photo folders, a movie or two, and even random images from the internet (specified by keywords) if you are really lazy or hurting for content.

Above: The set up tiles screen.

Once you select both your target and source images, MacOSaiX gets to work. The problem is , you don’t want it to. So, hit the “Tiles Setup” button to cancel the current job. From this screen, you can set up how fine a grid you want to create. The more tiles you use, the larger the result will be, and the better it will look. It defaults to a 10 x 10 image grid, but I suggest 20 x 25 or higher, if you have enough images. You can set up whether or not MacOSaiX can reuse images more than once, how many times it can and how far apart they need to be, as well as whether it must use the images “as is” or if it can zoom in a little to make better matches. Once you have the options set up as you wish, hit “Start Mosaic”.

Above: You can adjust MacOSaiX’s “fade” bar to get a better idea what the end result will look like.