Week 3: Scanning
Tuesday, March 17, 2009
Here is the Homework for Week 3 on scanning. Scanning is actually a pretty easy process once you have set up your scanner (both hardware and software). The scanner I am using at home is an EPSON Perfection 1260 and as I usually end up importing my scanned images into photoshop, my scanning process involves opening up photoshop, going to file>Import> TWAIN 5 (where my scanner is located) and then the scanner will start. There are 2 types of scanning modes, one is an Auto mode and the other is the manual mode. It is recommended to scan in Manual mode because that way, you are able to change the dpi, preview images and crop them, etc.
The scanning process from here onwards is pretty easy. Place an image or object you want to scan into the scanner and then in photoshop, select the Mode you want to scan in (RGB, Black and White, etc) and what dpi(dots per inch) you want them to be scanned in.
Some scanners may have a descreen button (in which case my one does not) which will help get rid of the occassional moire patterns that appear on your scanned image. While this has never happened to me, here is an example of scanned image with descreening on and off.
This image above is when descreen is turned off.
This image is when descreen is turned on.
Notice the difference in Quality??
Another item which changes the quality of a scanned image is dpi. Different levels of dpi are used for different things for example, scanning at 300dpi generally is for printing for glamourous projects such as glossy magazines, books and brochures while scanning at 100-150dpi is good for printing on normal inkjet printers. If you are scanning an image for the internet, then generally 72dpi is sufficient most of the time, however, through personal experience, I recommend that when scanning objects to post onto the world wide web, the smaller your object the higher your dpi should be (it is not really recommended to go over 300dpi).
Scanned at 72 dpi
Scanned at 150dpi
scanned at 300dpi
The images above were all resized to the same size but just so when the dpi changes, the size of an image will also change because the quality has changed. Can you see the difference??
Last but not least, scanning is not necessarily only for images/photographs. You can scan things in black and white such as line drawings and as well as things such as buttons, fabrics and zippers.
Fabric scanned in RGB mode at 72dpi
This one was scanned in Black and White. Again it is at 72dpi because the purpose of scanning this was to put it up on my blog.
So now that we know how to scan, let's go crazy!!
Scanned at 150dpi
scanned at 300dpi
