04.+Pixels

= What is a Pixel? =

All 3 pictures above are the same. The only thing different about them, is the number of pixels used to describe each picture. A digital image is made up of many pixels. Each pixel has a color. When the pixels are arranged next to each other, the resulting image looks like something. In the 5 x 5 pixel example above, you can actually see and count the pixels. But in the 100 x 100 pixel image, you cannot see or count them. They are too small and tightly arranged, but the resulting image looks nice. ** Suffice it to say: MORE Pixels = Better Image Quality. ** ** How It Works: ** The following is a simplification of how a digital image works: Let's say you have an image that is 6 x 6 pixels and you use Photoshop to display it on your monitor. Here are the steps that take place to display it: ** So, What is a Pixel? ** A pixel is really nothing more than a piece of information. A pixel describes where it is located in the grid and what color it is. Pixels, in a digital image, do not have a "Height" or "Width" that can be measured with a ruler. This is because they are pieces of information, rather than a physical thing that can be measured. **Once the picture is assembled on your Monitor or assembled for Printing, ONLY then can you measure it with a ruler.** The Rule of thumb when printing is: **More Pixels = Better Print Quality.** You can print a 6 x 6 inch picture, using a 6 x 6 pixel image, but it will look very bad. To print a 6 x 6 inch picture you really should have 1000 x 1000 pixels or more.
 * [[image:ms-blakely/ab1.jpg align="center"]] || [[image:ms-blakely/ab2.jpg width="97" height="103" align="center"]] || [[image:ms-blakely/ab3.jpg width="109" height="102" align="center"]] ||
 * **100 x 100** || **12 x 12** || **5 x 5** ||
 * 1) Photoshop opens and reads the file on your hard drive
 * 2) The file tells Photoshop that it is a 6 x 6 pixel image.
 * So, Photoshop sets up a 6 x 6 grid on your monitor: In this example, there are 6 x 6 = 36 cells that are empty.[[image:ms-blakely/a1.jpg]]
 * 1) Then Photoshop reads in the first of 36 pixels and asks what color it is.
 * 2) If the first pixel is blue, then photoshop makes the first cell in the grid blue
 * 3) The next pixel is read and asked its color. Photoshop makes the second cell that color
 * 4) etc, etc, until all 36 cells have been appropriately colored in.
 * 5) The picture is now complete and displayed.