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→Converting Between Types
Converting from JPEG to one of the other formats is lossless, but re-encoding it as a JPEG is lossy, so converting it back to JPEG will result in a different image than the original.
=== Bitmap to/from Vector ===
Converting a bitmap image to a vector is impossible or at least very difficult. You can have a look at this website for some information about [http://www.computerlifesavers.com/netsnippets/Art%20and%20Design/Auto-Tracing%20How%20To%20Convert.htm autotracing and other bitmap/vector facts].
== Scanning and OCR ==
* http://en.wikipedia.org/wiki/Gif
* http://en.wikipedia.org/wiki/Portable_Network_Graphics
* http://superuser.com/questions/53600/jpeg-vs-png-vs-bmp-vs-gif
= Lab =
This is a marked lab. Please submit it using Moodle (Lab2Lab3).
== Gimp ==
* The Gimp on the lab machines isn't fully installed so it may take a very long time to start up the first time.
* Find a JPEG photo online, with width:height ratio of 4:3. The contents don't matter - mountains, trees, flowers, sky, whatever. For exmaple something from http://amdwallpapers.webspaceforme.net/gallery/ Save the image as step1.jpgDon't use the same image as another student.
* Open the image with Gimp. Notice that most likely you're seeing a scaled down version, the zoom level is displayed at the bottom of the window.
* Save step4.jpg as step4.bmp. Note how much bigger the bitmap is.
* Save your JPEG in PNG format. Change the number of colours your image has, and save copies of it also in PNG format. For example change it to greyscale and save as another file, change it to indexed colours (palette) with a different number of colours and save as another file. Compare the sizes (in bytes) of the different files. There should be a non-trivial difference. If you have time left - save all these PNG files in JPEG format, and observe whether the numbers of colours make as big an impact on the size of a JPEG as they do on the size of a PNG.
== Dia ==
* Download and install [http://projects.gnome.org/dia/downld.html Dia].
* Draw your family tree (it doesn't have to be real, just different from other students) in Dia using shapes (perhaps boxes), arrows from children to parents, and lines without arrows between spouses. Change the colours for males to be blue (boxes and lines) and red for females.
== Submission ==
After doing all the steps above submit the following files to Moodle (Lab2Lab3)in a zip archive: step1.jpg, step2.jpg, step3.jpg, step4.jpg, family.dia, family.png, and one of the grayscale images generated by the last step.
