· How to use graphics and images

A few informative Web sites:

Resolution

Higher resolution means more dots per inch, means the dots are smaller.

The dots of "dots per inch" can be thought of as the individual elements of the picture. These dots, or picture elements are referred to as pixels.

Scanning resolution and printing resolution, at 100% scale, they are the same. Scanned resolution is what creates the actual image size. If the original has an area of 4 by 4 inches, that was scanned at 300 dpi, the image created is X by Y pixels now, 1200x1200 pixels. If you scale the image to print 8 by 8 inches, the printing resolution would be 150 dpi because you have spread the 1200 pixels across 8 inches.

A resolution arithmetic example -- if you scan 5x4 inches and print it half size to be 2.5x2 inches, and if you want to achieve 150 dpi on printed output, then you scan at half that, or 75 dpi. Because 5x4 inches scanned at 75 dpi gives an image size of (5 x 75) x (4 x 75) = 375x300 pixels. Scaling to print this at 150 dpi gives 2.5 x 2 inches, because 375/150 = 2.5 inches and 300/150 = 2 inches.

Color prints are only printed at about 200 dpi maximum. There is no reason to scan prints at a higher resolution. Negatives and slides are printed at resolutions of about 2000 dpi.

Onscreen display resolution is about 75 dpi. BUT, dpi doesn't really translate to inches and image size when displayed onscreen. Our monitors show a fixed area of pixels, which is usually 640x480 or 800x600 or 1024x768. Pixel size onscreen is determined by the current display settings of the workstation. The number of dots in the image will remain constant. Displayed at 640x480 screen resolution the pixels/dots will be bigger and result in a larger onscreen image than when the screen resolution is set to 1024x768 and the pixels/dots on screen are smaller. Likewise, scanning an image in at a higher resolution will result in more dots in the image. More dots to be displayed onscreen will result in a larger displayed image size.

So A 3x5 inch image scanned in at 75 dpi resolution contains fewer pixels than the same image scanned in at 150 dpi resolution.
When displayed onscreen the higher resolution image contains more dots so it will occupy more area onscreen.

For some examples and further explanation, see: http://www.scantips.com/interpol.html

If an image is enlarged/resized after scanning, the graphics program doing the enlarging has to make up information, manufacture pixels based on the original pixels. You could think of it as each individual, original pixel, getting bigger, therefore, resolution is decreased.

Resampling vs. Scaling -- Resampling is a very drastic change. Every single pixel is torn down and rebuilt. Actually, it's replaced with an approximation of others nearby. Scaling is not a change affecting the image pixels at all, rather, it affects the spacing of the original pixels on the printed paper. The original pixels are not otherwise affected, resolution is affected. You scale when you print. You resample when you resize the image (change the number of pixels) in a graphics program.

Connecting scanning resolution to printer resolution - for full details see: http://fla.esf.edu/research/CAVLab/reference/printers.htm
The bottom line -- Printer "dpi" is a different thing from image dpi (except in Line art mode). For inkjet or laser printers, here are good scaling guidelines for Color or Gray Scale photographs:

300 or 360 dpi printer - use 60 to 120 dpi image.
600 or 720 dpi printer - use 120 to 240 dpi image.
This statement is made for Grayscale and Color modes. Note the exception for line art mode, which is 1-bit 2-color (B or W, like ClipArt or fax), which contains no gray, no halftones, no dithering. In line art mode, the printer CAN use its full resolution, making use of the full resolution of the scanner.

So, what resolution should I scan at? There is no single answer that will cover all situations. Your answer will come from considering the points below.

Total pixel count is what's important. The total pixels you have to work with will determine image resolution depending on the image size you use.
Because the final resolution of your image is tied to the output device and image size that you are going to use, when you're scanning you need to ask yourself, "What am I going to use this image for and what could I possibly use this image for?"
Remember that you can never gain back pixels of an image by increasing the image resolution in image processing software. Once the pixels are gone, they are gone. When you increase the image resolution in a software package, the computer only looks at the existing pixels and makes its best guess for the pixels it adds to the image.
Based on the points above, one recommendation would be to scan your image at a high resolution (1200 dpi) and archive this image as a TIF. You can then work from this original, making your edits, and saving in other file formats as needed.

File Types

TIF -

No loss of information (which is important for edits)
Huge file size
Use this format when doing a lot of editing and re-saving of scanned images using PhotoShop, Paintshop Pro, or some other image editing program. When done editing, save as a .JPG file but you may want to keep the .TIF around as an original.

JPG -

Lossy (some information is lost in compression, may want to save your original)
Most efficient, resulting in the smallest file sizes
Stores 24-bit color (16,777,216 color) images
Designed for compressing either full-color or gray-scale images of natural, real-world scenes. Works well on photographs, naturalistic artwork, and similar material.
JPG's support over 16 million colors, but slightly "distort" the image to compress the file size. For photos, the human eye cannot tell the subtle changes in color, but along straight edges and in pictures with large solid colors, distortion becomes very apparent. (Note in the sample to the right how JPG leaves "ghosting" and distortion around the letters.)
Does not allow transparency.
Does not allow interlacing or interleaving.
Use this format as the final, post-edit version of the image that you will use in PowerPoint, Word, e-mail, and Web pages. Use a .TIF for the original to edit from and then save as .JPG.

GIF -

Compressed graphics format developed in 1987 by CompuServe.
Lossless (in compression no image information is lost)
GIF's reduce the color depth to a maximum of 256 colors to compress the size of the file. For most logos and text, 256 colors is more than enough, and will give you the best results.
Usually best for compressing low-color cartoon-like images, line drawings, and logos. (Note in the sample above how GIF's limited color depth affects a photo.)
Allows transparency. You can choose one color in the color palette that maps transparently when displayed. Gives the effect of seeing through an image or of an image floating on a background.
Allows interlacing or interleaving. Allows browsers to display a low-resolution image that appears immediately and continually redraws until it reaches its highest resolution.
Can create animated GIF images (as a single GIF file).

File Size

Larger files longer printing times and longer download times

TIF - huge file size (lossless), JPG - smallest file size (lossy)

Higher resolution more pixels more information bigger file size

Larger dimensions (inches) more pixels more information bigger file size

More colors, greater color depth more information bigger file size
(BUT, you can't save a JPG image at a reduced color depth.)
For more information about color depth, see: http://fla.esf.edu/research/CAVLab/Reference/candbd.htm

Scanning and Editing Tools

Flatbed scanner - Start | Programs | HP ScanJet Software | HP PrecisionScan Pro

- In the Menu Bar, click Scan | Preview to get a preview scan of your slide

- If the box (with dropdown) for resolution is not displayed in the toolbar, use Tools | Output Resolution to display the resolution selection box.

- Select the Output Type True Color, Grayscale, Black & White (vector, raster), 256 color, Text
This URL describes the difference between vector (scalable) and raster (pixels): http://www.cof.orst.edu/net/software/present/graphics/vector.htm

- Click and drag with the crosshair cursor to select the area you want to scan.

- Save (and scan) your image: Scan | Save As | and set the Save as type: in the dialog box

To save text (OCR - Optical Character Recognition) --
Click and drag to select the text area to scan -- Check in Output Type menu that Text is selected -- then Scan | Save As | and set the Save as type: to TXT
OR
Use Scan | Save as Whole Page

Slide scanner in the Lundeen Lab - Start | Programs | SprintScan35 | PolaColor Insight

You'll see the following screen when you open the program. Click Preview to preview the slide scan.

Go to the Scan tab to set the desired resolution.

You're also given some scaling options, by size or a percentage.
Don't get too caught up in having the scaling happen when you scan. Remember that you can scale in another program later and you don't have to do any scaling here. What's important now is, "How many pixels do you want to have to work with?" Set the Resolution accordingly.

When you click the Scan button you'll be prompted for file location and name and what file type to use.

On the toolbar, the info icon, , returns all the stats on the current image, including resolution.
The blue left and right arrows on the toolbar are useful to page you through the different images in the same directory as the File you have Opened.
The zoom icons, , are useful for images that may not fit within a fullscreen window.
The crop function is in the Edit menu, Edit | Crop
All other image editing functions you're likely to want are in the Image menu.
File | Batch Conversion/Rename will let you convert a number of files all at once (like from TIF to JPG). You can even use the Advanced Options and also apply any of the edits in the Image menu at the same time (the same edits to all images, like resizing to thumbnails).

You can create animated GIF images using Animation Shop which is installed as another tool when you install Paint Shop Pro. If the program is already installed, you'll find it in Start | Programs | Graphics
To install on your machine - Start | Run | \\abies\apps\win32\install\graphics\pspro.exe

Using Your Images

MS Word -- You have a number of options for how you insert your images into Word. For the definitive page of information from Microsoft, including links to many more pages of information and descriptions of strange behaviors where, "Microsoft has confirmed this to be a problem," go to: http://support.microsoft.com/support/kb/articles/Q167/7/38.ASP

Powerpoint -- Insert | Picture | From File will let you place an image file on the current slide. If you want the image to cover the entire slide, you'll have to resize and crop the image to dimensions proportional to the slide dimensions. You can crop and resize the image in an image editor like IrfanView before inserting the image or you can use Powerpoint tools to resize and crop.

Once the image has been inserted on the slide in Powerpoint, one technique would be to

Click and drag the image to move it into position in one corner of the slide.
Then resize the image so that the shortest dimension matches the slide and the other dimension slops beyond the edge of the slide. Be careful while resizing the picture not to destroy the aspect ratio and distort the image. (Click and drag a handle at one corner of the picture. Holding the [Shift] key down as you click and drag will preserve aspect ratio for all types of resizing in Powerpoint.)
Now you can crop the part of the image that extends beyond the slide.
To crop the picture from within Powerpoint you'll need the Picture toolbar --
View | Toolbars | Picture
When the floating Picture toolbar opens, click the cropping tool, .
Once you've clicked the cropping tool, position your mouse over a selection handle at the border of the image, and click and drag to crop using that handle.

If you're in a situation where you can't crop anything from your image to make it proportional to the slide dimensions, then you could set the slide size to the picture size in File | Page Setup. Of course this affects all the slides in the slide show. You could use branching (one show links to another, ...) to get around this problem. With the image open in IrfanView you can see the images dimensions in the window title bar.
PIXELS divided by RESOLUTION (dpi) equals INCHES

The Plotter --

Most people use Powerpoint to create their posters. The key is setting the paper size: File | Page Setup | Sized for Custom and specifying Height - Width - Orientation as appropriate.
A bit of plotter documentation is at: http://www.cof.orst.edu/net/howto/plotter/UsingPlotter.pdf
You talk to Helpdesk about scheduling a training time. Once you're trained you're added to the list of authorized users. Then, a few days before you're ready to print, make a reservation at the Helpdesk for the time you will need to print to the plotter. Expect to be charged for plotter supplies used.