SCANNING Page 2

On page 1 we discussed what scanning is, what it does, who needs it and the equipment needed. On the following pages we will cover how to scan.

There are a number of factors to consider before starting a scan. Lets look at these ideas:

• Graphics Vs. Text
	• Output
		• Push Vs. Pull
			• Resolution
				• Programs available
					Etc.

Lets take them one at a time. First lets consider Graphics Vs. Text.

Graphics is by far the easiest to do. This just involves taking a picture of whatever you put in the scanner and recording it.

Text can be scanned as a photo, but then it is just a photo of the text. It cannot be modified, words added, deleted, spelling corrected, etc. For text to be modifiable, it must be scanned as "text", not as a photo. This is a complicated process where the text on the page to be scanned must be "read" in such a way as to allow the computer to convert the page text into a font that is in your computer.

The process for doing this task is called Optical Character Recognition or OCR. Each dot on the paper must be recorded and an attempt made to create a character of the same letter in the computer font. Imagine trying to convert a handwritten sentence into a computer font. Improvements are made daily, but we still have a long way to go.

Most attempts at OCR create a lot of frustration. A lot of manual cleanup is usually required. The hardest item to scan is a form. Converting table, line and column format into something the computer can recognize is next to impossible. A lot of software packages make a lot of claims, but most are weak in my opinion.

Output

Before you scan anything, it helps to decide what the output will be, Are you going to make prints? Are they going to be enlarged? Are they going to be e-mailed to someone? Are you going to make a slide show out of them or store them on CD? Are you going to modify them? Once these considerations are made, you can then decide things like file type and size, resolution, etc.

Push Vs. Pull

There are 2 ways to scan. Push or pull. Push means to start a scan at the scanner and then send it to a program after it is scanned. Pull means to open a program and pull a scan into the program. We will look at both methods when we go into the process.

Resolution

This is probably one of the most important factors to consider and is most misunderstood and overlooked by most inexperienced users.

Resolution can be expressed in different terms, but basically means the quality of the scan. Higher quality yields larger file sizes and the ability to blow the print up larger without losing sharpness. Resolution also directly affects print quality. What is not affected is viewing it on your computer at the actual size of the scan. If you are scanning a small photo and want to blow it up on your screen, the sharpness of the photo in the enlarged state will be affected by the scan resolution.

Resolution or the sharpness of a picture (whether on video or a printed page) is measured in little dots. In video, the dots are called pixels. In printing, the dots are measured as DPI or dots per inch. In both cases, the closer the dots are to each other, the sharper the picture. How you have your video set on the screen will have a great bearing on the quality of the display. Having a high resolution printer will allow you to print high quality photos if you start with a high quality scan.

You will see numbers of 1200 x 2400 dpi, 48-bit and 600 x 1200 dpi, 48-bit and 600 x 1200 dpi, 42-bit as shown on the canon site mentioned above. The lower the numbers, the lower the price. The number refer to horizontal and vertical resolution in dpi. Obviously 2400 Dots in one inch provides much higher quality that 600 Dots Per Inch. With a 1200 x 2400, you can scan in any lower quality, but with a 600 x 1200, you cannot scan in any higher quality. Scanner prices are so low today, that I see little reason to choose any but the best.

Programs Available

One last decision needs to be considered. What program will be used to receive the scan. For (OCR) Text, the choice is limited to a wordprocessor. Text scanned as a photo is the same as any other photo.

There are an unlimited number of photo programs. All scanners come with a number of programs included free. Some are full featured. Others are Light or Limited programs that tease you into buying the full program. Various programs have various capabilities. I have used almost every graphics program available as a casual user. I am not a graphics person by nature or training, so my comments are in that light.

The most popular program (and most expensive) is Adobe Photoshop and is used by a majority of graphics designers. I got a free copy of an older version with my Canon scanner. I also got a suite of programs from Arcsoft that do some nice jobs. I have used MGI PhotoSuite over the years. I have used Paint Shop Pro for many years and is still my favorite for what I do. Presto and Micrografx have suites of programs. There are still others.

We do not have time to train or review on all these programs. Each program is so complex, it takes many hours to learn and practice what each one does. On page 3, we will cover the basics of using a program with suggestions of how to learn any program and general tips on scanning into a graphics program.