 Introduction
Guidelines
Graphic Software
Working
with Graphics
Printable
Version
(total tutorial)
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EXPLORING
GRAPHICS FOR THE WEB
Dr. Richard L.
Bowman
Academic Computing, Bridgewater College, Bridgewater, VA,
USA 22812
1. Obtain and install IrfanView.
Another excellent piece of free software that is easy to
acquire and use is IrfanView. It is now part of
the standard load on Bridgewater College lab computers.
If it is not on your office computer, contact the IT
Center to have it installed. For home use, download it
from http://www.irfanview.com/
. Its latest version is only 800 kB as a self-extracting
compressed file and thus downloads quickly. Download the
appropriate file and save it in a logical location on
your computer. Locate this file and double click on it.
Follow the dialogue boxes that appear. Most of the
defaults can be left as they are. Probably it is best to
select "Image only" to be associated with IrfanView.
2. Open an image and resize it. Run IrfanView
from the Start button or from its icon on your desktop.
From the File menu Open the logo file created in
Paint above. Move to the Image menu and select
Resize/Resample. Make certain that the "Preserve
aspect ratio" box is checked. Change the width value
to 75 pixels and notice that the length value also
changes appropriately. Then click the OK button. After
resizing is completed, one often needs to sharpen the
image. This can be done through the Image menu and the
Sharpen option. The amount of sharpening done with any
one selection of this option can be set through the
Effects and then the Effects Browser options in the Image
menu. Setting this to a value of 5 allows for one to
apply it several times to acquire the desired effect
rather than doing too much at any one time.
3. Save the image. Under the File
menu select "Save as" to save the image in a
different format. For web purposes, choose either gif or
jpg. For better color rendering, the usual choice should
be jpg unless a special transparency effect is desired
under the gif format. For web publishing set the quality
of the jpg compression to 90 or even 85. The smaller
amount produces a smaller image file (and thus a faster
loading image) but there might be more distortion at
lower quality settings.
4. Make other adjustments to an image as
necessary. When working with other images, e.g.,
from cameras and scanners, there may be other adjustments
that are necessary or desirable.
- One can crop an image to more clearly focus on
the object of interest. Quite often the pictures
amateurs take are too far away from the subject
and have too much extraneous material along the
border of the image. Crop it away! Remember the
rule of thumb: place the focus of interest in a
picture near the center of one of the quadrants
of the image. Cropping can be done in IrfanView
through the Edit menu.
- The color balance of the image may also be
adjusted for most realistic effect. Quite often
digital cameras or scanners will leave the color
balance of an image to be slightly
"unreal." Adjusting the color can often
be done by increasing the Gamma Correction
followed by increasing the contrast (this
brightens the image without washing it out) and
then reducing the intensity of the blue color
while increasing the red component. This is where
IrfanView excels. Software that comes
with digital cameras can usually do all of this
but may do it by sliders or wheels and not show
an associated number so that the effect is
difficult to reproduce. To make adjustments in
color, go to the Image menu and choose the
"Enhance colors" option. Remember, if a
particular adjustment does not look right, just
Undo it!
- Use the "Enhance color" option and the
"Effects browser" to make other
modifications to your images that your creativity
wants to experiment with doing.
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