CS101 Lecture 4 Computer Graphics

It ’ s just a bunch of pixels A computer screen is made up of many small colored squares called pixels The human eye blends the pixels together to form images on the screen.

Resolution Resolution = the number of pixels on a screen –Resolutions are expressed in pixels across the screen by pixels down the screen. 16:10 resolutions (Widescreen Computers) –1280 x 800 = WXGA –1440 x 900 = WXGA+ –1680 x 1050 = WSXGA+ –1920 x 1200 = WUXGA 16:9 resolutions (Widescreen TV ’ s) –1280 X 720 –1920 X 1080

Why change resolutions? Changing resolutions can improve productivity and decrease eye strain Low Resolutions = Individual items appear larger but have less work space High Resolutions = Individual items appear smaller but have more work space

Color Depth Color Depth = The amount of different colors that a pixel can be –8 bit color = 256 colors –16 bit color = 65,536 colors –24 bit color = 16,777,216 colors –32 bit color = 16,777,216 colors + 8 bit alpha Often called true color

Why change color depth? Low color depth = colors may not be accurate but computer has to process less information High color depth = colors are more accurate but computer must process more information

How do computers make graphics? Two ways: Integrated Graphics Dedicated Graphics

Integrated graphics Built into the motherboard. Uses system processor and RAM to generate graphics. Cheaper way to do graphics Slower graphics ability OK if doing low intensity graphic applications such as: –Word processing –Web surfing – –etc

Dedicated Graphics A graphics card is added to the computer which contains its own processor and RAM (this frees up the computer processor and RAM) Really helps graphic intense applications such as video games, CAD, video editing, etc.

New Way Accelerated Processor Unit Processor and Graphics built into one chip. –Less Power

How do I view my computer ’ s graphics ability? Windows 7 –Right click on the desktop and select “Screen resolution” > click “Advanced settings” Macintosh –Apple menu > About This Mac > More Info… > Graphics/Displays

Why is computer color RGB? How come computers mix red, green, and blue to make all other colors? –RBY is mixed to make all colors when using reflective light (things that do not produce their own light) –RBG is mixed to make all colors when using additive light (things that do produce their own light)

Things to look for in a LCD monitor Native resolution works well for activities you would like to accomplish on computer Good pixel response time for applications that have quick movement (movies, games, etc) Viewing angle wide enough for activities you plan to use monitor for Black level good for activities you plan to use monitor for Has a digital connection with HDCP (High Definition Content Protection) Make sure you can try before committed –Watch out for no return, high restocking fees, and shipping charges Try out everything you plan to use the monitor for before your return period ends Keep track of health while using