Photo Help

Scanning and graphics manipulation is one of the most misunderstood elements in computing. Getting your scanner up and

running is only the beginning and if you don't understand some basics about digital imaging you will be pulling your

hair out in no time. First some things you need to know about digital images:

DPI: Dots per Inch is what the name suggests, the quantity of dots of color per inch,and is most frequently referred to as

RESOLUTION. Most people assume that the more dots per inch, the better the picture will look. That is true..... sort of. The

problem is, it all depends on what you are using to view the picture. If you are going to just look at it on the computer monitor

then every dot per inch above 72 is wasted. Your monitor only shows 72 dpi and every dot above that is doing nothing

more than adding to the size of the file without adding one iota of quality. If you are printing the picture then generally 200 to

300 is about the max, depending on the printer and the way you have it set up. But, for most printers, 200 is about the best

you are going to do. Some scanning software doesn't even address the issue of DPI unless you dig way into the settings.

Instead it will ask you what your PATH is, meaning, where are you going to end up using the picture. It will give you a choice

of the "screen" or a whole listing of "printers." But, if yours asks you to enter the DPI then remember that 75 or so is good for

the monitor and 200 is good for most printers.

SCALING: Sometimes your scanning software will substitute the term "Percentage" for "Scaling." This is simply how big you

want to blow up the picture, with the original being the starting point. A 3.5 X 5 inch photograph scaled to 200 (or 200%) will

show on your monitor as a 7X10. So, before you scan determine what size you want the final image to be. Consider that you

may not scan the entire image either. More about that later.

BUT: Here is where it can get a little complicated. If you scale a picture to 100% and scan it at 72 DPI it will appear the exact

same size as the original on your computer screen. If you scan it at 100% but increase the DPI to 144 (double the DPI) it will

appear twice as big on your monitor, but will print to it's normal size on a printer that prints at about 150 DPI or greater. What

you are seeing on the monitor is the screen trying to show you all the Dots Per Inch you asked for. Since it can't cram any

more than 72 dots per inch on the glass screen it simply blows it up. This isn't important to you except to keep you

from getting very confused because a picture is much bigger on the monitor than you expected.

ANOTHER COMPLICATION: Sometimes, when you are printing a picture the computer will ask you what size you want

it to be. Don't think you can just take a picture you scanned at 5X7 and make it 8X10. It will print it that big alright, but it will

look terrible. Always print to the size you scanned (or smaller). If you want the print to come out 8X10 on paper then set your

scale or percentage to a number that will make the final scan 8X10.

COLORS: To make it as simple as possible. I recommend you scan all pictures, either black and white or color, in the best

possible color setting, which is usually called "millions of Colors." Scan B/W documents in "line art." This is not a hard and

fast rule and you can experiment with the document scans. Sometimes documents look better

when scanned as gray scales. But, if you are going to convert a scanned document to word processor text, commonly

called Optical Character Recognition (OCR), then you need to scan it as line art.

SCANNING: All scanner software comes with two-step scanning. The first is called the preview or initial scan. The scanner

scans everything on the platen. This is only the first step. The next step is to select what portion appears on the platen that

you want to scan, and scan only that portion. This is very important. When you put the mouse pointer over the picture it will

become a cross hairs. Put the mouse in the upper left corner of where you want to crop (actually, any corner will do) then,

holding down the left mouse button drag the cross hairs to the furthest corner from where you started.

When you let go there will be a box around what you want to scan. If you don't like the cropping you can start over,

or you can just put the cursor on any of the four sides and adjust the box. Then hit FINAL or whatever your scanning

software calls the last step. The software will pop up and ask you what you want to call the picture and where you want to

store it on your hard drive. Give it a name, find a place for it, and hit FINAL. This two stage process is standard, but the

methods and names used by different software packages varies greatly. Some even have automated systems that are

SUPPOSED to make it all very easy. Read your manual.

FILE FORMATS. This can get very, very complicated so I will try and reduce it to what you need to know. Most scanners limit

the kind of format you can create when you scan a picture. Format is the three letters after the name of

the file, for instance: mypicture.tif or mypicture.bmp . TIF is Tagged Image Format, and BMP is Bitmap. JPG or JPEG is the

most widely used format. The three letters at the end of every single file in your computer is often referred to as the

EXTENSION and simply tells the computer how to handle the file. Both of these formats (tif and bmp) will show your

pictures at their very best, but at a huge cost in drive space. A 5X7 picture scanned in millions of colors can use anywhere

from 3 to 5 megs of space on your hard drive. It's not hard to see that if you scan a lot of pictures and forget about

them you will eventually use up most of your hard drive.

But, you've got to scan them as something and since your scanner won't give you too many choices you can pick either one.

There is a difference in the two formats but for our purposes the differences are not important. Pick one and stick with it. I

suggest TIF. Also, create a folder on your hard drive for your initial scans and always put your pictures there.

Ok, you've scanned a picture called myhouse.tif and saved it to a folder on your hard drive called familypictures, so the path

to the folder would be C:\familypictures\myhouse.tif.

Now, what do you want to do with the picture? If you want to print it, just open up your graphics program, bring up the picture,

and print it. That's all there is to it, unless you need to fix or clean up the picture. That is a function of the kind of graphic

program you use and I won't discuss that here.

What if you want to e-mail the picture to someone? You could e-mail it as is (myhouse.tif), but the person you are sending it

to will not be happy receiving a huge file that will most likely take an hour to download. So, the next step is to convert it to a

file format that is more efficient for e-mailing and screen viewing. The standard is JPG and is what you will see most often

on web sites. On the screen a JPG and a TIF or BMP will look exactly the same, but the JPG, because of efficient data

compression, is a much smaller file. A 5 meg TIF can be reduced to a 35K JPG file. It won't print worth a damn, but it looks

just as good on the screen (all things being equal, and I will get into that next).

The easiest way to convert a file from a TIF to a JPG is to use the software that came with your scanner. These days most

scanner software includes a little wizard that will take a picture and process it for e-mail. It will reduce the resolution to 72 DPI

and change the picture to a JPG. If not, you can just have the picture open in your graphics program and do a SAVE AS.

You can keep the same name, but change the extension to JPG. If you have already scanned it at 72 dpi, you will be

ready to mail it.

ONE SMALL BUT IMPORTANT DETAIL: JPG can be saved as a specific quality. The quality scale is sometimes 1 to

100 but I have seen it rated at 1 to 200. In any case, there is not a noticeable bit of difference between the very best quality

and a few numbers less, but the file size is very different. You will need to experiment on what you find acceptable in the final

product, as a trade off for file size. If you saved it as a 20 quality your file size would be 1 or 2K. It would zip through the e-

mail at the speed of light, and look horrible. Usually, 90 in the 1 to 100 scale is about the right level.

Anyway, that's about all there is to it, except for a lot of stuff that is of great concern to layout artists and web production

people. To us folks who just want to email pictures around, the rest doesn't matter much.