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Images for the Web, August 2003
Some Internet service providers (ISPs) such as AOL have their own cache to speed up page loading for their subscribers. The downside is you're usually not seeing the best quality image or even the correct image, if it has recently changed. The image file's contents could be completely changed and the file name kept and this would cause you to see the previous image, rather than the actual current image until the cache is cleared.
So, now that we know that we should resize an image before we use it on our web page and we should state its proper dimensions in the image tag, what's the other common mistake we should avoid? File size. File size is made up by the number of bytes used to compile the image. The more bytes, the larger the file. The larger the file, the longer it takes to load.
Not to pick on Lucy Liu anymore, I will show you examples using a picture I took of a dragonfly. The original image taken with a digital camera was 1760 x 1168 in pixels and a file size of 6.167 megabytes. That's mega as in million. Those dimensions are way too big to display well on a web page and you could eat a sandwich waiting for it to load 6 meg, even if you have broadband. Remember, some visitors still use dial-up modems. Still, I want to share my dragonfly picture with you on the web, so I have to make it faster loading and a reasonable size. Continued>>>