Demystifying the Pixel

What is a Pixel The smallest unit of measurement in a image It contains color space information in RGB, CMYK, HSB Resolution information Bit Depth Information (as in number of colors possible) -- this will depend on Resolution

Pixel - As a unit of measurement The smallest unit of measurement in a image

Pixel - Color Space Color Space information is represented in –RGB –CMYK –HSB

Pixel - Resolution Info. Resolution is represented in Pixels Per Inch (PPI) - –The higher the resolution, the higher the print quality, the lower the resolution, the lower the print quality –72PPI (Screen Resolution –300 PPI (most common print resolution) –1200PPI (slides) Resolution is represented in Dots Per Inch (DPI) –Refers to the maximum resolution of a printer –Printer X prints Y number of dots (representing color) per pixel. The larger number of DPI printing in a pixel, the better quality of the printed image.

Bit Depth Information A pixel includes Bit Depth Information representing “number” of colors possible. Bit Depth is represented in “Zeros” and “Ones” How many colors? This will depend on the number of bits per pixel (bpp) of an image. –To check: open image in Photoshop -> Menu -> Image ->

The higher the bit depth, the more detail you see in an image 1 bit color is 2 1 =2 colors 2 bit color is 2 2 =4 colors 3 bit color is 2 3 =12 colors 4 bit color is 2 4 =16 colors Bla bla bla 8 bit color is 2 8 =256 colors 12 bit color is 2 12 =4096 colors 16 bit color is 2 16 =65536 colors 24 bit color is 2 24 = colors 32 bit color is 2 32 = colors 1 bit 4 bit 8 bit

Exercise Calculate how many colors are in a 44 bit image? How many pixels are in screen resolution image of one inch?