EXPLORING
GRAPHICS FOR THE WEB
Dr. Richard L.
Bowman
Academic Computing, Bridgewater College, Bridgewater, VA,
USA 22812
IV. Scanning (Digitizing)
Pictures
A scanner can be used to scan photographs and other
pictures so that they are in a digital format such as
jpeg. Pages of text can also be scanned, and then optical
character recognition software may be used to convert the
image of the text back into real characters.
To do the actual scanning at Bridgewater, the HP
scanner in MCK 226 (or those available in other
locations) may be used. IrfanView can be used to
access the appropriate software to control the actual
digitizing of the image. Run IrfanView and from
the File menu select Acquire. Wait while the scanner
software is opened and follow the prompts to obtain the
image. To OCR a document, go to the Start button and
select the appropriate scanner software from there.
Note: When using scanned
pictures or diagrams from other sources, be sensitive to
copyright restrictions and protocols!
V. Converting from One
Graphic Format to Another
As noted earlier in this tutorial, the output from Paint
is in bitmap form, that is, it will have the extension
.bmp as part of its file name, but the two main graphic
formats in use on the Internet today are gif and jpeg (or
jpg). To convert a file from one graphic file format into
another, simply open the file in a graphics program and
then use the Save As option from the File menu to save it
in the proper format and with the correct extension.
While the latest versions of Paint can save
images in gif and jpg format, my suggestion is not to use
it do so. Paint does not allow the user to set
the parameters that are allowed in each of these file
formats. Rather, it simply sets what it considers to be
the most usual default values. IrfanView, on the
other hand, lets all of these parameters under the
control of the user.
Hint: When saving a graphic
file that is to be used on a web page, it is a good idea
to keep the file name short and to make certain that no
spaces are included in the name.
Note: While the jpeg format uses a
pretty good compression routine and allows for a full
24-bit color scheme, the gif format for images sometimes
makes a smaller file. The gif format has a maximum of 256
colors and is thus not appropriate for photographs, but
it can be a good choice for logos and other
"constructed" graphics. In addition, one of the
gif format versions allows for the specification of a
transparent color. This can be useful with logos and
other graphics where one desires the background to show
through if it is changed.
VI. Inserting Pictures or
Graphics into a Web Page
Assuming the necessary image is already copied into
the same file folder as the web page you are
constructing, open the appropriate web page in FrontPage
and position the cursor at the proposed location for
the graphic. From the toolbar press the
"Picture" button. Browse to locate the graphic
file, or simply type in its name. Complete the
installation of the image by pressing "OK."
Right click on an image in FrontPage and select
the "Picture Properties" option to make some
adjustments in how the image will be displayed on the web
page.
Graphics (photographs, buttons, or other images) can
be made to be active hyperlinks to other web pages.
Simply click once on the image and then select the
"Hyperlink" button in FrontPage. In
the dialog box add the address of the web resource to
which you desire to link.
First Hint: It is very
important for those using browsers that do not support
graphics and for the visually handicapped that a web
author provides alternative text which will be displayed
when the graphic cannot be displayed. This can be added
through the "Picture Properties" option.
Second Hint: DO NOT RESIZE
the image in FrontPage! This will not really
resize the image; it only resizes how it is displayed.
The browser algorithms that do this are of poor quality
and the file still takes the same amount of time to
download since its real size has not changed. If an image
needs to be resized, do it in IrfanView or
another graphics program with good algorithms for doing
this.
VII. More Advanced Topics
There are many other advanced paint and drawing
programs on the market or available as shareware. Check
the PC archives on the Internet for more choices. And by
all means, keep experimenting and looking for more
effective ways to communicate with your students and
colleagues through your use of graphics on your web
pages.
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Introduction 
