| Goals for this chapter: | rpm packages covered in this chapter:
|
This short chapter is about Web images. The images are the most fundamental part in the Web. An HTML page without images simply have no sense. In this chapter we will explain how to locate the images that you browse some minutes ago as well as how to locate on the Web special Websites dedicates to this matter.
In the Web there are different Web sites specially dedicated to offer
cliparts and images for free. We list here the most common web sites:
| This is the most common place to go to look for cliparts and images. |  |
|
This is another free Web site where is possible to obtain
cliparts and other images. There are 12,000 images that can help your Web site development. Other similar web sites are: AAAClipart.com |
 |
|
This website contains 1,212,898 images organized in
cliparts, photos, fonts, web art and sound. |
 |
Of course you can also using the Web Search Motors: like Altavista,
Yahoo,
google,
...
The Nteascape cache dir.
The Netscape Communicator (or the Navigator), includes from the first version a directory called "cache", inside the "~user/.netscape" directory. "~user" stand for peter, mary or root, home directory.
[root@www /root]# cd .netscape/
[root@www .netscape]# cd cache/
[root@www cache]#
Inside these directories
[root@www cache]# ls -F
00/ 02/ 04/ 06/ 08/ 0A/
0C/ 0E/ 10/ 12/ 14/ 16/ 18/ 1A/
1C/ 1E/ index.db
01/ 03/ 05/ 07/ 09/ 0B/
0D/ 0F/ 11/ 13/ 15/ 17/ 19/ 1B/
1D/ 1F/
[root@www cache]#
For example, we can enter in the first directory:
[root@www cache]# cd 00
[root@www 00]# ls -al
total 76
drwxr-xr-x 2 root
root 4096 May 21 08:47
.
drwx------ 34 root root
4096 May 20 20:17 ..
-rw------- 1 root
root 3944 May 21 08:35
cache3B090BA01B041F9.jpg
-rw------- 1 root
root 2162 May 21 08:35
cache3B090BA01B141F9.gif
-rw------- 1 root
root 4163 May 21 08:35
cache3B090BA01B241F9.gif
-rw------- 1 root
root 11577 May 21 08:39 cache3B090C8024941F9.jpg
-rw------- 1 root
root 6966 May 21 08:39
cache3B090C8024A41F9.jpg
-rw------- 1 root
root 14038 May 21 08:39 cache3B090C8024B41F9.jpg
-rw------- 1 root
root 16123 May 21 08:39 cache3B090C8024C41F9.gif
We can browse these files with the KDE image broswer.
[root@www 00]# pixie *
Of course you can browse all the images running the command:
[root@www cache]# pixie */*
In other words you can browse again all the images that you browse some days ago, because there are present on your hard disk, in this directory.
The assignation between images/html pages and websites are present in the file: "index.db"
The images may be saved for years in this directory. The size depends
on the setting that you fix in the Preference "Cache" mask.
How to create images with GIMP and StarOffice
Around the Web you can find any type of images:
For example, we have:
GIF - Graphics Interchange Format
developed by Compuserve online services.
JPG - Joint Photographic Experts
Group
BMP - Microsoft BitMaP
PCX - PC PaintBrush
TIFF - Tagged Image File Format,
also TIF
PNG - Portabel Netwok Graphic
StarOffice is a well know program that includes StarDraw to create images and flow chart.
To enter in StarDraw simply, run "soffice" and the choose: File -> New -> Drawing.
This program is very complete and allow to export images to any format.
On non-linux system like the Mac, there are available products like Macromedia DreamWeaver and FireWorks. A good solution is to develop Web sites on these platforms with commercial products and use Linux like a Web Server.
How transform images between formats.
You can use StarOffice for Web images and the GIMP for indexed or alpha:
| GIMP support any type of image: Bitmap, PNG (portable
Network Graphics), TIFF and other formats.
One of the reasons because GIMP is complex is because it uses a different approach on menu-popup. These menus are present on the image window, not in the application
window like in StarOffice, or Adobe Illustrator
|
 |
The GIMP however, is more indicated to manipulate images, like Adobe Photoshop does. Is also usefull to save images in Alpha or indexed format.
StarOffice also supports different formats for export.
Some times, may be important to use or create animated GIF.
As explained in the BASE course there are an enormous discussion on the GIF algorithm, however this kind of images continues to be used.
pixie to be included in FTOSX will create dynamic gifs, in a future release.
How to add sound to your HTML pages
In this section we will explain how to add sound to your web pages.
You can check for example FTYellowPages or LatiNet
Sound files haves the following extensions:
Now, the lines to add after the BODY declaration are the following:extension, name origin variable parameters (fixed; comments).au or .snd NeXT, Sun rate, #channels, encoding, info string
.aif(f), AIFF Apple, SGI rate, #channels, sample width, lots of info
.aif(f), AIFC Apple, SGI same (extension of AIFF with compression)
.iff, IFF/8SVX Amiga rate, #channels, instrument info (8 bits)
.voc Soundblaster rate (8 bits/1 ch; can use silence deletion)
.wav, WAVE Microsoft rate, #channels, sample width, lots of info
.sf IRCAM rate, #channels, encoding, info
none, HCOM Mac rate (8 bits/1 ch; uses Huffman compression)
none, MIME Internet (See FAQ: Audio File Formats )
none, NIST SPHERE DARPA speech community (See FAQ: Audio File Formats )
.mod or .nst Amiga (See FAQ: Audio File Formats )
<BODY BGCOLOR="#FFFFFF">
<NO EMBED>
<BGSOUND SRC="audio/latsnd.au">
</NO EMBED>
<EMBED SRC="audio/latsnd.au" HIDDEN=TRUE
AUTOSTART=TRUE VOLUME=100>
...
The previous example is simple and effective. When you hit the page, automatically you will start to hear the sound of the file: latsnd.au
These files AU (AUDIO) are originally from Sun Microsystems.
In Chapter 23 Multimedia, in BASE Course we cover how to transform CD->MP3->WAV.
Here, we will relist these topics.
For example suppose that you want to publish the John Lennon's Image on your Web site, from its Mp3 version.
At first we create a raw file from the MP3 file, running the command:
mpg123 -s John\ Lennon-Imagine.mp3 > Imagine.raw
Then, we create the WAV version running sox, sox stand for Sound Exchange
sox -r44100 -s -w -c2 Imagine.raw Imagine.wav
Then again running sox, we create the AU version.
sox Imagine.wav Imagine.au
At last adding the lines
...
<NO EMBED>
<BGSOUND SRC="audio/Image.au">
</NO EMBED>
<EMBED SRC="audio/Image.au" HIDDEN=TRUE
AUTOSTART=TRUE VOLUME=100>
...
You will hear the Image song. Be carefull to includes no-copyright songs.
Read the answers to
the exercises.
Check the Interactive Exam Cram WebMaster: 
Internet Resources for this Chapter.