Photo Scanning!
Scanning with Dave!
I would love to be able to come over to your house for dinner and a chance to go through scanning with you, but since I can't, here's the next best thing I can offer. I would suggest printing this out, firing up your computer, and pretending this paper is me. (Paint a little smiley face on it.) Scanning is probably one of the most confusing topics for most people because of the different variables involved. When you combine that with all the different scanners and software programs available, it may seem even more confusing. Don't give up though! I'm sitting right here and we'll go through some of the basics together!
First thing, turn the scanner on, fire up your computer, and start up your scanning software. Wow nice system! I really like what you've done with the room too.
OK, lets grab a photograph we want to scan. Hey a nice color 4 x 5. Is that really the president standing with you? I'm way impressed! All right, quit bragging and lets put the picture in your scanner.
The next thing we're going to do is a "pre-scan" of the photograph. When you do this, the scanner makes a quick pass over the image and shows us a low resolution version of the image on the screen.
Hmm, now somewhere in here your scanner software is going to have a selection tool. Lets find it. There it is! We're going to use the selection tool, to select the part of the photograph we want to scan. No you do it, it's your computer.
Move the selection tool to the top left part of the picture area that you want to scan. Good... now click and hold down the mouse button. Don't let go! Keep holding the mouse button down while you drag down and to the right, selecting the part of the picture that you want to scan. When you get to the bottom right part of the picture that you want to include, release the mouse button.
That's it? You didn't want to include the president? Ooh, I understand, the press and everything.
OK, so now that we've got the part of the picture selected that we want to scan, we need to adjust some settings. The first thing we need to do, is to tell your program that we want to scan this as a "24 bit" image. We need to set it for that so that we can get a good quality scan that's going to capture all the colors in the photograph. How many colors is 24 bit? It's somewhere over 16 million. Yes, I know it's a lot. No, 8 bit, 256 colors won't work. No, the 16 bit, 32,000 colors won't work either. I know it seems like a lot, but that's what you need.
Even with the 16, bit 32,000 color setting, your scan will loose a lot of the color range in the photograph. Plus, you see that halo over the presidents head? Well at 16 bits, it would look banded. The smooth graduation in the glow would get rough and wouldn't blend smoothly. Oh yea, that's right, your not scanning him in. Well, you need the 24 bit setting anyway. Trust me.
OK, so we've got the mode set. We set the scanner to color and we've made sure it's set for 24 bit, 16 million colors. Now lets take a look at the size of the area in the photograph that we're going to scan.
Hmm, somewhere here in your scanner's software window, it's going to tell us the size of the area we have selected. There it is! It says the area is 2" x 3" and right over there it says 100%. Right, that's telling us that we have it set to scan that 2" x 3" portion of the photograph and that the scanned image is going to be the same size, 2" x 3".
Is that the size that you want the scan to be? No, you want it bigger? How big? OK, we can do that. You want your finished scanned image to be 4" x 6". So, to do that, what we're going to do is change that 100% to 200%. That will tell the software to make the scanned image twice as big. That was easy! So now, it showing us the area we have selected, that it is a 2" x 3" area, and that we want the scanned image to be 200% (twice as big) as the original.
OK, just to get familiar with this, lets say you want scan to be only half as big as the original. How would you do that. That's right, change the image size to 50%. Hey, your good! No wonder the president likes you.
Hey, we're getting close now! There's only one thing more we need to do. We need to tell the software what resolution we want to scan the image at. Uh, resolution means how dense the pixels or dots will be in the image.
Pixels? Hm, OK. A scanned image is what is called a "raster" or a "pixel based" or a "bit mapped" image. What that means is that there are a whole bunch of dots of colors that are combined together to create the image we see on the screen. Dots, pixels, they mean the same thing. Yea, sort of like cross stitching. Hey, I never thought of it that way. That's great! Can I use that?
So, the scanned image is a "bit mapped" graphic and a "bit mapped" graphic is made up of a bunch of pixels, or dots, with each pixel having a color. We also have to set a resolution for the image too because bit mapped images can have different resolutions. The "resolution" is some information that is actually stored in the graphic file and tells software programs and printers how many pixels should be shown or printed in each inch of the graphic. It's pretty important too because you use different resolutions for different things.
Speaking of which, what do you want to use the scan we're doing for? Are you going to be printing it, sending it to someone in an email or putting it on your web page? OK, so you want a copy of it that you can use for printing on your color printer and a copy that you can put on your web page.
We can do that, but we're going to make 2 different images. We need 2 different ones because we want to have an image at a high resolution that for printing and one at a low resolution to use on your web page.
What's the difference? Well, for the one for printing we want to create an image that is at least 150 dpi (dots per inch). Actually, for your ink jet printer, 300 dpi would be better. Let me take a look at your printer's manual for a minute. Yea, I know, people never read them, they just invite me over for dinner.
OK, you're ink jet printer will print text at 600 dpi and graphics at 300 dpi. So, if we do a scan of your photograph at 300 dpi, you'll have an image that will print at the finest level possible for your printer. Any higher resolution than 300 dpi would be overkill because the higher the resolution of the image, the bigger the file size gets. And it does a lot more than double the file size too. Yea, I know, the 600 dpi thing on the printer is confusing. Most people think that because it can print at 600 dpi, that it prints everything at 600 dpi. They don't necessarily work that way though. Besides, 300 dpi should give you a real nice looking picture.
So, we'll do our fist scan at 300 dpi. Now lets see, yea right there. You see where it says "Resolution" on the screen? Change that to 300. Yes they are all different. Every darn one of them. Mine says DPI instead of resolution. Sure would be nice if they could all get together on some of this. That's OK though, we're getting it!
In fact, I think we're ready to scan! Lets, check everything. We've got the part of the picture selected that we want to scan. We're scanning it in color at a 24 bit color level. It's showing us that we have a 2" x 3" area selected on the photograph, that we're scanning it at 200% which is going to give us a scanned image that is 4" x 6", and that the scanned image will be at a resolution of 300 dpi. It's also telling us that this is going to be a 4 megabyte file! That's right, these puppies can get real big, real fast. That's one of the reasons you don't want to set the resolution higher than 300 dpi. It also may be why you might want to take a look at the CD-R that was on sale. If you're going to be doing very much of this, you'll eat up disk space real quick.
OK, we're ready. Click the scan button!!! I hate to trouble you but while this thing takes a couple of minutes to scan, could I trouble you for another cup of coffee? No, just black. Thanks!
Hey, it's done! Yes, it does look huge. That's because your computer monitor only has a resolution of 72 dpi so it's showing us the scan at that resolution. Let's save the file though and print it. You'll see it's the right size for your printer and it should look really great!
But before we print it, lets go ahead and do another scan for you web page. Do you want to change anything on it? No, OK, then we just need to change the resolution setting for it. Right, back in there, change it from 300 to 72. How about the size? Do you want it to be 4" x 6" on your web page? That's pretty big. The same size as the original? OK, lets change the image size back to 100%. Yup, it's that easy! Now, let's click the scan button again. Hey this is really good coffee!
It's done! See how this time the scan actually looks 2" x 3" on your monitor? That's because we changed the resolution to 72 dpi, and set the image size back to 100%. This will look great on your web site! Let's save it with a different name than the first one. That's it! Say, you don't happen to have any more of that desert do you?
Article by David Sutphin, Dream Maker Software
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