Bad Web Design: ActiveX

Written by Richard Lowe

ActiveX uses an interesting method for enforcing security ... it doesn't. Well, that's not exactly true. What happens is when a web page requests an ActiveX controlrepparttar browser determines if that control is already loaded onto your system. If it isrepparttar 134677 ActiveX control is executed. If not,repparttar 134678 user is asked if it is okay to installrepparttar 134679 control. Additional information about whererepparttar 134680 control came from and it's security implications is also included.

The theory behind this security model isrepparttar 134681 user knows what's best for his system. In my humble opinion, this is pure hogwash (a stronger expletive came to mind but this is a family site). Is your average web surfer really knowledgeable enough to make a decision like this? Look at it this way, by installing an ActiveX control you are assuming it is secure, won't damage your system and is bug-free. You are basically trusting completelyrepparttar 134682 company which createdrepparttar 134683 control,repparttar 134684 developers andrepparttar 134685 people distributingrepparttar 134686 image.

Yes there are security certificates involved, but those are relatively easy to get. Also remember how many security problems have been reported involving ActiveX controls.

I don't know about you, but when I get that little box stating a site wants to install an ActiveX control, my first impulse is to hitrepparttar 134687 NO box, quickly followed byrepparttar 134688 BACK key. This may seem a bit paranoid, but I use my computer all day long and I depend upon it for business and pleasure. Why would I want to put it at any risk for some silly little ActiveX control? The web is a huge place and there are plenty of other sites to look at.

Graphics for the web: GIF Format

Written by Richard Lowe

The GIF (Graphics Interchange Format) format was invented in 1987 by Compuserve to allow images to be displayed. This format allows for 256 colors (which was a lot atrepparttar time), compression, interlacing and animation. It is a very powerful format, suitable for many different types of images.

Due torepparttar 134676 limited number of colors, GIF is primarily useful in images with a distinct separation of colors. A cartoon, for example, is ideal forrepparttar 134677 GIF format.

When you save an image in GIF format, you haverepparttar 134678 option to specify how many colors will be saved. By doing this you can decreaserepparttar 134679 size of an image even further. All ofrepparttar 134680 tools which are available to optimize GIF images work by reducingrepparttar 134681 number of colors torepparttar 134682 bare minimum. This can produce astounding results inrepparttar 134683 size ofrepparttar 134684 finished file.

Unlike JPEG, GIF uses a non-lossy compression algorithm. This means that images do not loose bits when they are decompressed. In order to accomplish this, GIF uses a proprietary encoding/decoding scheme called LZW (Lempel Zev Welch). LZW is an excellent compression algorithm which typically results in very small files (in comparison to fully expanded BMP files).

This compression method is actuallyrepparttar 134685 cause of a bit of controversy. As it turns out, LZW is owned by UniSys, and overrepparttar 134686 past few years they have made some attempts to collect licensing fees for products which save inrepparttar 134687 GIF format. These attempts have had mixed results, and has causedrepparttar 134688 development of a new non-proprietary standard called PNG.

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