People sometimes assume that using an autotrace feature (such as LiveTrace) is the best way to convert a photograph into vector artwork. Sure, autotraces are easy and fast… But you can get MUCH better looking and easier to edit results with a little elbow grease.
Choosing a Reference Photo
First off, you’ll need a photo. Your source photo doesn’t have to be perfect: The white balance could be a disaster, your highlights blown out, full of noise. None of this matters if you’re going to end up with a vector file!
There are some things to keep in mind when choosing a reference photo, though. Nice, evenly lit photos tend to be tricky to work from, as there’s not a lot of definition between shadow and highlight. So you’ll want to look for an image that has lots of dramatic shadows. You can always lighten them in your final vector, but seeing where the shadows are is critical.
We’re using a snapshot taken with a cheap point and shoot of a mountain range in Banff National Park, near Calgary, AB:
We’ve sized the photo down to 800 x 600 pixels. There’s no need for a super high res image as it’ll just slow Adobe Illustrator down as you work.
Go to Illustrator’s main menu and click ‘File > Place’, then select the photo you would like to use. Move the image around your artboard until you’re happy with how it is placed:
Lock the layer the photo is on (so it doesn’t shift around) and create a new layer. Some illustrators like to reduce the opacity of the photo so they can better see the lines they draw on top, but I prefer to use bright colors on my strokes so they’ll stand out.
Breaking Down the Shadows and Highlights
First off, we’ll decide how many shades/colors we’ll need to draw in. The more levels of color and shading you add the more you’ll end up drawing, so we’ll keep things simple here and decide on 4. White for the snow highlights, pale blue for the snow shadows, medium gray for the mountain and a darker gray for the shading on the rocks.
Some people prefer to alter their source photos in Photoshop before drawing, such as applying the ‘Posterize’ filter to break the photo down into manageable shade levels. We prefer to work right off the photo, though, without having software choose where our shading will be. If we wanted to do that, we’d just autotrace the photo! By working on our own we’re able to massage the details and tweak the shading to create a more dramatic effect.
Drawing the Base Shapes
Let’s draw our mountain base. We’ll add the snow and shading over top.
Select the pencil tool (‘N’). We’re using the pencil tool because it’s a lot faster than placing points one by one, though if you’re not working with a tablet it may be harder to use. Since the shapes of the rock don’t need to be too precise, the pencil tool is our preferred tool for the job.
Setting our stroke color to red (so we can see it over the photo), we’ll draw along the top of the mountain. It doesn’t have to be exact:
Pencil tool tip: As you’re coming to the end of your shape, hold down the ‘Option’ key as you stop drawing. Your path will automatically close itself.
Note that we aren’t drawing the sides or bottom yet. Instead, we’ll draw a rectangle over everything, making sure it lines up on the artboard. Select everything and use Pathfinder’s ‘Divide’ tool to chop the rectangle along our mountaintop line, then delete the overlapping shape on the top. Now you’re left with the mountain base shape (shown without the photo showing):
Adding Highlights and Shadows
Next we’ll start with the snow highlights. Using the pencil tool, trace over all the lightest areas of the mountain. We’re setting the stroke color of these shapes to green, so that we can tell them apart from the red base shape.
Here’s where we’re at now, shown in outline mode. Don’t worry, once we add the colors in it will look much better!
Note that we’re using the Pathfinder again in order to clean up any shapes that hang off the artboard. It’s much easier to tidy up as you draw than after you’re stuck with dozens of layers and groups of shapes!
Now we’ll trace the darker areas of the snow, again using a different colored stroke (purple). Last, we’ll trace the shading on the mountain using orange:
Here’s the outline view with the photo layer turned off:
Looks pretty weird hey? Don’t worry, just trust your eyes for now. Let’s add our colors and see what we get.
Before adding colors, we need to do some cleanup. We have a whole lot of little bits and pieces here and trying to keep track of them all will be a nightmare. So, we’ll merge each colored shape using the Pathfinder tool. This will help us recolor each shape, as well as make sure we don’t forget a piece when moving shapes around.
Starting with any shade area, click on one shape and go to Select > Same Fill & Stroke. With all shapes selected, click the ‘Add to Shape Area’ button in the Pathfinder palette. Repeat for each shade area: Snow highlight and shading, and mountain shading.
Adding Color Fills and Gradients
We’ve decided to add a slight gradient to each level of shading, just to add some depth. Starting with the mountain, we’re using a light gray that blends to a slightly darker gray at a -70 angle (which matches with where the sun in the sky is in our source photo):
We’ll use the same gradient angle for all our shade levels. The rock shading is darker gray, the snow highlight is white shading to a very light blue, and the snow shading will be a darker blue (just like in the photo):
Here you can clearly see where we weren’t able to fully draw the mountain, on the left and right. That’s because our source photo has 2 trees in the foreground. So let’s get on that!
Adding in Trees
We’ll draw the trees the same way we tackled the mountain: With the pencil tool. We didn’t trace them precisely as they were in the photo (that would take forever), instead we’ll just scribble with a thicker stroke (2 point with rounded caps) to get the same effect on the branches.
Once you’ve scribbled enough, select the stroke and click ‘Object > Expand’. This example shows an unexpanded stroke on the left and the expanded version on the right:
One word of advice when expanding complex strokes like this: Illustrator likes to add some gunk that you don’t need. In this case, you’ll probably end up with some extra shapes that don’t have strokes or fills assigned. To delete them, draw a box with no fill or stroke and while it’s selected go to Select > Same Fill & Stroke and delete whatever is selected.
Since we’re lazy, we’ll just copy the tree and flip it horizontally, taking care to resize it then trim off any stuff that hangs off the artboard. For color, we’ll use another gradient from a mid to darker green shade.
After we’ve added in a sky (also shaded with a subtle gradient) here’s what we end up with:
Thanks very much to Isaac, who suggested we show how our hand traced version would stack up against some autotraced versions. Great idea!
Here I’ve taken my original photo and ran 4 different default Live Trace functions on them in Adobe Illustrator CS4. Click on the thumbnail to open a high res JPEG of each file, along with a 100% closeup zoom so you can see some of the details. Pardon the obnoxious watermarks please!
Final file size: 1.5 MBs (AI CS4)
OK this one’s pretty obviously rubbish! The lack of detail in the source photo has led to some serious weirdness in the shadows and highlights. In particular, note how the wispy clouds behind the peaks have totally merged into the top of the mountains! Adding more color steps might help…
Final file size: 1.8 MB
Not so much! Here, the additional 10 color steps have only served to make this photo messier than ever. The thing that really bugs me about this is how impossible it would be to edit if you wanted to change up the colors. I also don’t like the weird grayish ghosting that’s now happening around the pine tree edges: That’s a sure sign of an autotrace that wasn’t well planned.
Final file size: 1.7 MB
Next up we’ve tried the Low Fidelity Photo setting. It’s slightly better than the 16 Color setting… But has many of the same problems, such as ghosting around the pine tree and where the mountaintops merge into the clouds. If you look at the closeup you’ll see we’re starting to get a lot of very strange little shapes in a range of not so attractive colors (bright blue, medium brown).
Final file size: 3.5 MB
Last but not least, we’ve tried the High Fidelity setting. If you lean back from your monitor and sqint really hard, it kinda looks like mountains. But the closeup? Egads! It would take months to sort out what shape ends where, and the file size is massive (considering no gradients are used here). The sky in particular is a jagged, choppy mess.
Final file size: 2 MBs (likely from all the gradients I used)
The hand drawn version isn’t as contrasty as the previous autotraced examples, but here’s the thing: the contrast could easily be tweaked. Why? Because this file is nicely divided into only a few simple color levels, and, each colored area is placed on its own layer.
Now, I probably could have tweaked my Live Trace settings to get better results… But it’d take a LOT of trial and error, especially trying to find a good balance between the details in the mountain, sky and the trees. Ideally, I’d need to trace each element separately to ensure the cleanest detail (which means I’d spend a lot of time isolating in Photoshop, which would probably take much longer than drawing by hand!). Also, drawing over the photo by hand means that you’ll know for sure that customers will get a clean, organized file, nicely tidied up with layers and groups, with no surprise colors or shapes.
It seems like this conversion took a long time but it honestly didn’t. I could probably complete something this detailed in an hour (I’ll time myself next time I draw something similar). With a mouse, it would have taken me a lot longer, but having a tablet really speeds things up when you’re using the pencil tool.
The pencil tool used with a tablet is great for tracing details like this because they don’t need to be super precise. It’s almost like drawing on paper.
Another reason for drawing by hand is that the source photo is poor quality. A higher resolution photo may have yielded better results in an autotrace, I don’t know. But the lack of detail and the amount of noise and compression in my source photo meant in order to get the best results, I’d need to tackle it by hand.
One more thing to note about LiveTrace is that it’s a pretty complicated tool and takes a lot of know-how. I’d strongly recommend you check out some good tutorials on how to use it, such as this article by Cheryl Graham.
© 2009 Jennifer Borton