The default computers to be used in this course are the HP workstations: adder, king, and habu) in the Engineering Design Center, where a directory is set up for this class:
/home/adder/classes/e186
You can find sample programs, image data, handouts, and other files related to this course in this directory or its subdirectories. These directories are read only. You cannot change any of the files. You are supposed to copy whatever file you need to your home directory (or ftp the file to whatever computer you prefer to use) and then edit, compile and run the program as your own copy.
If you have any problem using the HP stations, send email to "system@adder" for help.
There are various ways you can obtain an image. First, quite a few digital image files are stored in /home/adder/classes/e186/imagedata subdirectory. Second, you can use a digital camera to take, or a scanner to scan, your own pictures and then transfer the image files to the computer where you will do further processing. Or, you can down load images of interest from various web sites in the WWW.
The best way to really learn image processing is to write your own programs instead of using packages. And it is not difficult, if you follow the instruction below.
(1) A software called XV is available on the HP workstations (and easily available on most other unix stations). XV is able to display digital images of many different formats in the X-window environment and convert a given image from its original format to any of the other formats. In particular, as our sample program processing.c (discussed below) only uses PBM format, you need to convert all images in any other format to PBM You first display the image that need to be converted in XV, then you saveit in PBM (raw) format. If the image is Black/White, save it as a Grayscale image (with .pgm as the name extension), if it is a color image, save it as a Full Color image (with .ppm as the name extension). Never use B/W Ditered format, which will give a .pbm extension. If you want to see the pixel values with 0 representing black and 255 representing white, you can use the middle button to click anywhere inside the image.
(2) Use a sample program /home/adder/classes/e186/programs/processing.c to process the PBM image (with either .pgm or .ppm extension). You are to copy this program to your own directory (computer) and modify, compile and run it to process the images. The detailed information about how to use the program can be found at the beginning of the program.
<3> The output image (the processed image) from the program processing.c is always in in PBM format) and can be readily displayed using XV.
First, use XV to display the image and save it in postscript format with .ps as the name extension: filename.ps. Then you can print this file using the commend:
lp -d"printer_name" filename.ps
where "printer_name" can be any of the names of the printers available in the Engineering Design Center:
Or, you can print an image file using these commends:
These commands will print most common image files in formats like tiff and gif. They employ scripts and programs which change the given image to postscript so that the printer can process it. The scripts work best when the image file has the standard filename extension for a file of a given type.
To save paper, you are to submit electronically your results of a project by copying all image and text files to:
/home/adder/classes/e186/students/proji
where "proji" can be proj1 through proj7 for any of the 7 projects. Always attach your last name in front of the specified filenames. For example, if one of the images you are supposed to submit in project 5 is called "image1.pbm", you should rename it as "your-last-name_image1.pbm" before copy it to /e186/students/proj5.