Laurens Graphic Design Blog: September 2014

Wednesday, September 17, 2014

Format Notes

Image compression-

Makes it worse and smaller in file size. Also makes it look and sound worse

DVD=Compressed video. Every document is packaged in different formats. Graphic files like photo video or artwork can be reduced in file size by compression. Compression throws away data that it doesn't need. GIFs fall under categories of compression, Lossy and Lossless.

Lossy-

Image data is lost and can cause poor image quality and a small file size.

Lossless-

Retains image data for higher quality but larger file size.

TIF, JPG, GIFS are the 3 most common activity's like printing, scanning, and displaying images.

PNG- Common web format that is high quality and can contain an alpha channel which makes transparencies.

TIF- Common format for desktop publishing, print, photo, and graphic design. Its a lossless file format and retains image data for maximum, not internet friendly. Larger file size.

JPG- Joint Photographers Export Group. Created for digital photography, and works best for photo content. Its a lossy format and the compression is adjustable.

GIF- Graphic Interchange Format. Best for graphics or images that have flat color or even tone such as a cartoon. Reduces image size by indexing color from 3 channels to 1. Adjustable by changing color bit levels from 1-8. Contains no DPI (Dots per inch) data for printing. There are also 256 color in gif.

Tif and Jpg are best for images with pixels that blend in color these are called contiguous pixels.