What does dithering do? What are the problems with this and how does it relate to the color palette (10 points)
Dithering is a method used that allows a person to take an image from a high bit rate like 24 down to 8 bits so that the colors can be seen on the new bit size. Dithering is the process of juxtaposing pixels of 2 colors to create an illusion that a third color is present. It makes the image very grainy and sharpness is eliminated. If the viewers monitor is set out of teh color scale of an image the image will be dithered and in order to fit in the safe viewing preference.
Why is GIF the most popular graphics format on the web? (10 points)
GIF files are so popular because they have a compression scheme to keep files size to a minimum, allowing them too be viewed easily. They are reuired to have 8 bit color palette. GIF files use standard forms of the file LZW that eliminate inefficiencies in the file without losing data or distorting the images. The LZW scheme is best at compression images with large fields of homogeneous color
What are the advantages and disadvantages of the JPEG format for web graphics? (10 points)
JPEG images are full color images, 24 bit "true color". On pictures where the image quality and color fidelity are of the utmost importantance and cannot be compromised by dithering, JPEG might be the most fesible soulution. The compression scheme that JPEG are great. It can obtain a remarkable compression ratio, converting images down to 100 times smaller than the original file. But, this process still degrades the images. Also, once the images are compressed using JPEG compression, the original data will be lost and cannot be recovered. So then it is always a good idea to save the original uncompressed file and make a copy to compress.
Color is displayed differently on the screen and by a color printer. How? Why does the computer screen display colours as well as the printer? (10 point)
Four-color printers are separated into for major printing colors: cyan, magenta, yellow, and black. These for colors combined produce the perception of a full range color on the page, but as you can tell by the name the printed images only realy contain foru colors. Whereas, current computer monitors can display a ultitude of colors. Computer screens also display the colored light that shines from the screen, known as transilluminated images. This offers a much greater range of contrast and color intensity than images printed on paper. Finally, screens show color images using the red-green-blue (RGB) spectrum this allows for more color than the 4wheel.
In displaying an image with HTML why use height and width tags? How are colors represented with HTML? What do you need to look out for when using a background color or pattern? (10 point)
The height and width tags tell the browser how much space to allot for a specific graphic on the page. It tells the browser to follow a blueprint and design the look of the page before the images are downloaded. The color is specified in the tag in hexadecimal code, in which the six elements give the red, green, and blue values that blend to make the color.
When choosing background colors, the legibility should be the most important factors in determining the background- text color combination. Choosing the wrong combination of background-text colors will only make it harder to read. One should choose contrasting colors. The best and most common is black text on a white background. Now we are begining to see a new problem arise. The issue of backgroud patterens. Background pattern is touchy subject among Web designers, it is at the center of many heated debates in the computer world. Large patterns takes much longer to download and often time make the page even harder to read. People must be careful when using patterns such as these.