SESSION 19

a)
The most common image file formats,are JPG, TIF, PNG, and GIF.

JPG is the most used image file format. Digital cameras and web pages normally use JPG files - because JPG heroically compresses the data to be very much smaller in the file.

TIF is lossless (including LZW compression option), which is considered the highest quality format for commercial work. The TIF format is not necessarily any "higher quality"

GIF was designed by CompuServe in the early days of computer 8-bit video, before JPG, for video display at dial up modem speeds. GIF discards all Exif data, and while GIF is fine for video screen purposes, GIF does Not retain printing resolution values. 

PNG can replace GIF today (web browsers show both), and PNG also offers many options of TIF too (indexed or RGB, 1 to 48-bits, etc).

b)

It's JPG, because because JPG heroically compresses the data to be very much smaller in the file.

c)