TCS - Internet Sig Report
Internet Sig Report
by Don Singleton
Tulsa Computer Society
From the August 1997 issue of the I/O Port Newsletter
Preparing Graphics For Use On A Web Pages
The Internet Sig meeting on Monday, June 30 was well attended, and we had a good discussion of various aspects of Graphic Images as they apply to use on a Web Page. We talked about thumbnail images, so that one did not need to download large graphics that they were not interested in, the differences between interlaced and non-interlaced images, how to make a background on an image transparent so that the background of the web page surrounds the image rather than it being in a rectangular white field, and how one can modify a GIF animation to remove certain cels of the animation, and how to speed up or slow down the transitions between different cels.
We used the GIF Construction Set, LView Pro, and WebImage, all available for download from entries on the TCS web page, at http://www.tcs.org/webpage2.htm #GRAPHICS.
As we have been doing at several of the recent meetings, I asked Don Sanders to write down the questions posed from the audience, and I will attempt to reanswer them here, to let people who were not at the meeting know what sort of questions people who were at the meeting had an opportunity to get answered, and hopefully others with questions will come to some future meetings, to learn from some and share their knowledge with others.
Where Can One Find a Program to Syncronize Their Computer's Clock With a Standard Clock?
If you go to TUCOWS (http://tucows.phoenix.net/) or the first entry on the Software entry from the TCS Other Web Pages table (http://www.tcs.org/software.htm), and select either Win 3.1 software or Win 95 software, and then select Time Synchronizers, you will see that "Time synchronizers can access your local internet server and compare the difference between the actual time and your PC clock. It can also automatically correct the time for you."
Windows 3.1 users can choose between:
Atomic Clock Synchronization
This Windows Sockets Application allows you to synchronize your CPU time-of-day (TOD) clock with any daytime server available on the internet. Many Naval observatories maintain atomic clock times and will allow you to connect to their daytime server using this application.
NetDate
A great, tiny program that checks the time for you for the clock that hasn't been right since you brought your computer home. Resets your clock if you wish. Sets for your timezone. Auto off after set. Extras. Really easy to use, and only uses a few seconds of your online time
Tardis
A program that synchronizes your PC clock to the servers.
WinSNTP 16-bit
Simple Network Time Protocol that runs under windows.
All of the above were rated "4 Cows" (TUCOWS highest rating is 5 Cows, so 4 Cows is pretty good).
Windows 95 Users will see:
AtomTime95
An NTP client that connects to the atomic clock time server. Well worth the download.
Dimension 4
Incredibly easy to use SNTP client for Windows 95 and Windows NT 4.0 (SUR) synchronizes your PC's clock to within 50ms of US Naval Observatory or other NTP server.
NetDate
A great, tiny program that checks the time for you for the clock that hasn't been right since you brought your computer home. Resets your clock if you wish. Sets for your timezone. Auto off after set. Extras. Really easy to use, and only uses a few seconds of your online time.
NetTime
NetTime is a Windows 95 taskbar tray application that keeps your system clock synchronized to a server running the RFC868 time protocol.
Socket Watch
An NTP client specially designed for Windows 95 and Dial-up Networking.
Tardis
The latest and greatest time synch program for windows 95. New version includes clients AND servers for time. Also includes more useful new features, including automatic server switch over and tooltips.
YATS32 (Yet Another Time Synchroniser)
Allows you to automatically set your system clock to any of a number of time services available via the internet or your corporate intranet. It supports multiple servers, and multiple time service protocols. It will even poll a list of different servers till it gets a valid time stamp.
WinSNTP
Simple Network Time Protocol runs under windows.
Tardis and YATS32 won the coveted 5 Cow Rating, the others got a 4 Cow or 4.5 Cow Rating.
What Is Winsock?
In Windows 3.1 your ISP probably gave you a program called Trumpet Winsock to connect to his service. With Windows 95 he probably instructed you to use the connection software built into Windows 95, and made very easy to use by the Internet Connection Wizard first distributed in the Windows 95 PLUS package. Whether you use one of those programs, or some other program he may have provided you to Dial his service and connect to it (and I am not talking about a Web Browser like Netscape or Internet Explorer that he might have provided you as well), once that connection program dials his modem, it answers, and the program exchanges your name and password, a connection is established, and your computer is now on the internet, with its own unique IP number (which it will retain until the connection is broken, and the IP number is reassigned to some other caller). When the connection is established, the dialer stores the IP number in the computer for use by some code called the Windows Socket Interface, or WinSock for short.
A WinSock connection, by itself, does no useful work, but once it is established then the user can run as many WinSock Client programs as he wishes, at the same time, and they will all share the connection to the Internet. The user may run a web browser such as Netscape or Internet Explorer, which will use the winsock connection to connect to certain web sites, such as http://www.tcs.org, and then take the packets that are sent back and format them on the screen so the user can read the information, view the graphics, and perhaps take additional links to other web sites.
The user may also use their web browser for email, or they may run a separate email client, such as Eudora, or the Win95 Exchange program, or any of a number of other email programs, which will share the winsock connection, and request new email from the ISP's Mail Server.
The user may also use their web browser for UseNet News Groups, or they may run a separate specialized UseNet News Reader, such as Free Agent or WinVN.
There are a very large number of different Winsock Clients that the user may also use. We discussed many of these at the Internet meeting on June 14 (see the article on page 6 of this issue), and if one goes to either Tucows or Stroud (first two entries at http://www.tcs.org/software.htm), he can download as many WinSock Clients as he wants.
How Do Interlaced and NonInterlaced File Sizes Compare?
In one test I ran, an interlaced image was 195,470 and a non-interlaced image was 185,400, which means the non-interlaced image would be slightly, but only slightly, faster. The main decision that one needs to make in deciding whether to use interlaced or non-interlaced images, is whether the viewer would want to quickly see the general outline of the image, and have it improve in quality as additional data is downloaded, or whether they would be more likely to stay and view the whole image if it was slowly revealed in a windowshade fashion, but that once a part was revealed, it was already the best quality that it would ever be.
What is the Resolution of a Monitor?
As Paula Sanders indicated, 72 dpi.
Comparing two different photos, is the resolution of both really 72 DPI?
It is possible that one is higher, but if so the higher resolution will be wasted, because the monitor will only display 72 dpi. If you are providing an image whose primary intent is that it be saved and printed on a printer, it might make sense for it to have a higher resolution, but that will just make it take longer to download, so it might be best to offer the viewer a thumbnail that he can click to get a larger image for viewing purposes, and a separate thumbnail or other item to click, to download a much larger image for use with a printer, but which will not look any better on the screen than the other large image.
What Is the Difference between HTM and HTML?
The second one has an "L" at the end. Both extensions are legal, and both are interpreted as meaning a web page, coded using the Hyper Text Markup Language. A Windows 3.1 program can only build files with the three character "htm" extension. A Windows 95 program can build files with the four character "html" extension, but it can also just call the files "htm" and they should work just as well.
When You Pick a Color Using WebImage's Transparency Mode, Is That the Color That Becomes Transparent?
Yes, anywhere on the image that that particular color is found, will become transparent, and the background will show through.
Are There Some Colors That Can Be Coded To A Non-Standard Color? Sometimes Web Page Colors Look Good on One Machine, and Are Washed Out or a Different Color on Another Machine.
Some of the older Web Browsers can only support a limited Color Pallet. Also different monitors may behave differently on different machines, or under different lighting conditions. Ask Paula Sanders sometimes about the difficulties she has gone through trying to calibrate her monitor and her printer, so that what she saw (on the monitor) was what she got (on the printer).
How Can You Avoid Wasting All of the Time to Download Graphics You Don't Want, When You Use the Internet To Get Information.
In Netscape go to Options, and make sure the Auto Load Images is not checked; if it is checked click it to turn the check mark off. Then it will not download graphics, although you can click on the small multicolored images associated with each graphic that was not downloaded, and download that one graphic. In Internet Explorer you can do something similar, but I don't recall exactly what menu it is in.
How Do You Get To The Link To GIF Construction Set?
From the main TCS web page (http://www.tcs.org) click Other Web Pages, which takes you to http://www.tcs.org/webpage.htm. This is a table with a number of different categories, each of which represents a page of links associated with that category. Use the Elevator Bar (Scroll Bar) on the right to go down a little (or use the PgDn Key) and there is another table with the date and subject for each Internet Sig Meeting. Click on the one for June 30 Preparing Graphics For Use On A Web Pages, and it gives you links for both 16 bit (for Windows 3.1) and 32 bit (for Windows 95) for:
Graphic Programs available from TUCOWS
GIF Construction Set for Windows
AniMagic
Graphic Workshop
Lview Pro
Paint Shop Pro
WebImage
along with some sample images showing interlaced vs non-interlaced graphics, the effect, both in download time, and quality of image, when one reduces the colors in an image, and some animated email icons.
What Is Binary Email?
When one sends a binary file by email, regardless of whether it is a graphic file (tif, bmp, gif, jpg, etc) or a program file (com or exe) or some word processing file (doc, sam, wpd, etc), or any other file containing more than just letters, numbers, and a few special characters, then the file must be converted by the sending program (or by the sender, using a separate program before sending it), and then it must be deconverted on the receiving end, either by the receiving email program, or by the recipient, using a utility to convert the file back into something useful. We will discuss and show this in great detail on August 25 when we cover Sending Email via the Internet, and one can download a file called BINASCII.ZIP, which is available on the TCS BBS or from the Internet by scrolling clear to the bottom of http://www.tcs.org/webpage.htm and clicking on "utilities used to handle binary email."
How Do Your Print More Than One Image On A Page (Not a Web Page, but On The Printer).
The best place to bring something like this up would be at the Word Processing / DTP Sig Meeting in room U2 of Keplinger Hall on the 2nd Wednesday of each month. It is easy to show, but not that easy to document, so come to one of the meetings and let us show you.
Where Is The Link To LView?
As shown above, LView is one of the programs shown on http://www.tcs.org/webpage2.htm#GRAPHICS.
Will Paintshop Pro handle Vector Images? Are Vector Images Smaller Than Raster Images?
Usually vector images are smaller than raster or bitmapped images, because they just store the mathematical formula for a graphical element, rather than all of the dots that make up that element. I am unfamiliar with Paintshop Pro (which was one of the graphic utilities we listed on the web page entry for the June 30 program); why don't you download it and see what it will do?
What Graphic Formats Does the Web Support?
Browsers will handle JPG (JPEG) and GIF files directly. Plugins are required to support other formats.
Are The Programs Shown In The Web Page For The June 30 Meeting Free?
They certainly don't cost anything to download and try out. Some of them are freeware, which means they are completely free, and some are shareware, which means that if you like them, after trying them out you are encouraged to send them some money. That encouragement might be as simple as telling you each time you use them that they really would like you to send them money, or the program may stop working, either completely, or partially, after the trial period. I know that WinImage, for example, will let you use it after the trial period, but it will no longer save files after the trial period, until you register the program.
Where Can You Locate MIDI files On (or Off) the Internet?
The Midi Music SIG will have a special program on just this subject at their September 15 meeting at 7:00 pm in the Harmon Foundation meeting room, 2901 S Harvard.
What Are Cookies and How Can One Avoid Them?
Cookies are very misunderstood aspects of the Internet. On some systems when you visit a web page that you have visited before, it will say welcome back, we have not seen you since March 17 at 3:43 pm, and people will panic, thinking the server has somehow been maintaining a lot of secret data on them, and they worry what uses that data might be being used for. For one thing, the cookies are not stored on the web site's computer, they are being stored on your computer. The first time you visit a site it gives a command to your browser to store a small file on your computer associated with that web page, and then the next time you visit it asks if you have any stored data associated with that web page, and if it does, it asks that cookie be sent to it so it can extract the data, which includes the date and time it was stored, and provide that welcome message.
One web page cannot read another web page's cookies, and the data that is stored in the cookie is information provided by the web page. Some useful uses for cookies include being able to have your computer remember the password you were assigned when you signed up for access to certain web pages (such as the New York Times or the Electric Library), and when you visit certain sites that sell merchandise, such as the book store at http://www.amazon.com, as you go through their pages and select a particular book to be "put in your shopping basket" what happens is the web page stores a cookie on your computer with the book you selected. When you go to the "checkout register" to actually order and pay for the books, the web page "reads its cookies on your computer" and asks you to confirm that you want to buy each item in your shopping basket.
If you are still concerned, and want to know when a web page tries to store a cookie on your system, in Netscape if you go to Options, Network Preferences, Protocols, the alert check boxes determine whether you receive a notification dialog box (popup alert) when accepting a cookie (unchecked, by default) or submitting a form by email (checked, by default). The dialogs notify you before information is transmitted.
If a check box is checked, the notification dialog can be issued; otherwise, the dialog is bypassed. Each time you view a notification dialog, you can uncheck the Show This Alert Next Time check box within the dialog. If you uncheck the dialog's check box, the corresponding check box in the panel is automatically unchecked. To have the notification dialog shown again, check the alert item in the panel.
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Tulsa Computer Society 07/07/97
Don Singleton, President
tcs@galstar.com