A very well known and apt adage for many circumstances, but today I'm not going to talk about the virtues of a picture in it's ability to replace words or describe more effectively. Today, I want to use this space to help those unfamiliar with the ways in which we can make images work for us on the Internet, especially beginner webmasters or those who haven't had a lot of practice at using images so they aren't a liability to their website.
Unfortunately, for the lack of a bit of knowledge, many webmasters, the uninitiated and some of the relatively experienced, are using images in such a way as to disadvantage themselves and their websites. The most common problem I see is images that are way to big (and I don't mean physical size), which only serves to slow their website's loading time. I've noticed there are a number of webmasters who either aren't aware of the fact that a website is no place for a bitmap image (.bmp) or they don't know how to convert it to a more friendly file.
Firstly, we have to establish the major file types (or file 'extensions') that are used on websites. These are, as I just mentioned, bitmap (.bmp), which is a MS Windows® format, jpeg (.jpg), gif (.gif) and to a lesser degree png (.png). These initials all have meanings, for instance 'png' stands for 'Portable Network Graphics' but it's really of no consequence to name them all.
As I said, except in a very few circumstances, bitmap images have no place on a website, simply because of the size of the file needed to carry them. They certainly have their uses but this isn't generally a recommended use because they can slow the loading speed (the time it takes for a web page to appear on a user's screen) to a virtual crawl, unless they are a very small or 'simple' image in terms of color and content.
Other file types can also be too large, especially when the image is a color photograph. Color photos consist of a lot of visual information in order to be 'photo quality' and consequently, even in jpeg format, probably the most popularly used image format on the Net, they can be quite large files. So, you ask, "How do I deal with this - what can I do if I have an image that I really want to use, but it's too big?" No problem.
First, you need a good 'Image Editor'. It's simply a program which can resize, crop (trim), reduce the quality and most importantly, change the 'file extension (image type) of any image, among many other nifty things. Your standard MS Paint® program is useful, but it has many limitations and is not really good for 'editing' images in the real sense. For my money, which is somewhere around 'free', you can't go wrong with 'Irfanview'.
Irfanview is an excellent 'Freeware' Image Editor which can be downloaded and installed through their website [url]http://www.irfanview.com[/url]. In my opinion, the only thing it can't do is change the file extension of an 'animated gif' (the moving images that you see everywhere), which I think is beyond almost any program.
Now you're armed with what you need to make your images work for you, instead of you building your website around your images and their 'foibles'. If you have a bitmap image that is 500 Kb, you can turn it into a jpeg of approximately 25 percent of the file size, or even smaller, there are many variables. In some cases, gif and png files can be even smaller than that. You can make the file even more manageable by reducing the quality of the image by, say 10 percent (hardly noticeable in many cases) and cut the file size by up to 30 percent again.
You can crop (trim) edges or parts of the image, which don't need to be shown to reduce file size. You can convert to 'grayscale' (a black and white photo type image) if color isn't too important and save a lot of file size. You can reduce the physical size of the image (although it won't change file size, it can make your images fit where they don't want to), keeping the original ratio of length to width or 'stretching'. You can even 'capture images' (take screenshots).
You can also invert and reverse, turn 90 degrees left or right etc. Basically, if you can conceive of it, within reason, you can do it. So hopefully, now many beginners and budding