Photoshop CC: The True Nature of Pixels

Here are some basic facts about pixels that you really need to know. While reading this article may not improve your love life, allow you to talk to ghosts, or give you a winning lottery number, it can help you understand what happens to your image as you work with it in Photoshop.

• Each pixel is independent. You might think that you see a car, a circle, a tree, or Uncle Bob in a picture, but the picture is actually just a group of small colored squares. Although you can read about different ways of working with pixel sets, each pixel exists in and of itself.

 

• Every square pixel (except for what appears on TV). really! Each pixel in a digital image is square except when creating images for some TV formats, which use non-square pixels. It’s important to understand the squaring of pixels because sometimes you have to deal with those little pointy corners.

 

• Each pixel can be exactly one color. This color can change while the image is being edited or altered, but each pixel is entirely made up of one color – there is no such thing as a two-tone pixel.

 

• Smaller is better (in general). The smaller each pixel, the better the detail in the image. (However, when you make photos for the web, you need smaller photos that always have less detail.) If you take a picture of a house with an old cell phone camera and take the same shot with a new DSLR (Digital Single Lens) reflex camera – you know, one Interchangeable-lens cameras) that capture three, seven or fifteen times as many pixels – it’s pretty clear which photo has better detail.

Smaller pixels also help mask the bad angles of pixels that are sometimes visible along curves and diagonal lines. When pixel angles are noticeable and degrade the image, you call it a bad case of jaggies.
Keep in mind that the size an image can be printed at – and still looks good – depends on the number of pixels available. Sure, it seems every mobile phone these days captures at least 10 megapixels, which is fine for 8 x 10 prints and perhaps as large as 16 x 20 inches. But what about the pocket’s 10MP camera not having a zoom long enough to film Tommy’s little exploits on the far side of the football field? This is the time when you may need to crop and reshape the image to increase the number of pixels.

• Pixels are aligned in raster. The term raster appears regularly when discussing images created from pixels. Raster, in this case, refers to the nicely organized rows and columns in which the pixels appear. Each image contains a certain number of rows of pixels, and each row contains a certain number of pixels – columns. Within a raster, the pixels align perfectly side to side and from top to bottom.

 

• Each image created is in rectangular pixels. Some pictures may look round, star shaped, or missing a hole in the middle, but they won’t be unless you print them out and pick up the scissors. The image file itself is rectangular, even if it appears round. The pixels are already located in those areas that appear to be empty; The pixels are transparent. When printing, the transparent areas display the color of the paper you are using.