When it comes to drawing, I particularly like doing pencil portraits (as you’ll see in my illustration portfolio). Drawing from a photo can be quite a challenge as you have to interpret all the different colours and convert them into something you can put down on paper. I’m sharing a couple of tricks that I use to make drawing from a photo slightly less taxing. You’ll need a digital photo and some image manipulation software to do this – I use GIMP, which is a free alternative to Photoshop but there are plenty to choose from.
You may think this is incredibly obvious but from a technical point of view, it makes a huge difference. A standard colour image has a palette of 16,777,216 different colours. When you convert it to greyscale, the computer converts each of those colours to a shade a grey taken from a palette of just 256. Narrowing down the number of colours by this vast quantity is a very good start but 256 is still quite a few; I would be very impressed by anyone who could reproduce all 256 shades with a pencil.
Posterising an image simply means to reduce the number of colours in the palette so we can cut the 256 shades of grey down even further. The number of shades that you need often depends on the image but I like to keep the Posterise Tool open and change the number depending on the amount of detail I want at the time. Generally, I find 8 colours is usually a fairly good balance though. The posterised image makes it much easier to see where to focus the dark and light tones. It also makes it easier to liken greys in different areas of the photo.
Have a look at the pictures below and see for yourself (photo by Scott Gries, 2009). Click on the images to enlarge…