SEO for Images on Web Sites

SEO for Images on Web Sites
+ c# k) ]% w1 q: A( [/ o1 P$ l! cby Patrick Heath****

0 ]0 i4 |: A+ t4 A# xExcellent images are essential for web sites and can lift an ordinary web site to a professional level. The average surfer responds better to websites that use good quality images, tending to linger longer and browse more pages than when faced with dense, text-heavy pages. There are many reasonable priced picture libraries online where one can source everything from flower pictures to computer equipment images.

9 u5 j3 Z. c; i8 e6 u* p+ vHere are a few rules that need to be followed to ensure that the images become an asset to your site rather than an unwieldy burden and that your careful SEO use of keywords in the text is enhanced by the images:
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8 ]7 r0 T" o6 M) K8 v1. Make sure all your images are correctly optimized: i.e. a relatively large image of 600x475 pixels should be between 20KB and 50KB in size(maximum). If you use a lot of thumbnail images on one page (125x125 pixel) then they should be between 5KB and 10KB in size.
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  I+ E' ?& S8 l" S8 DBy sticking to these simple size guides you will ensure that your page loads quickly. Do check every single image that you put up. I have seen images on websites that are 2MB in size, leaving the web site owner scratching his head and wondering why the page takes so long to load. Casual surfers will have long since departed to faster loading sites.

2. Naming your images appropriately will substantially help by making it easier for Google to find the images on your web site (Google has recently changed its algorithm to take into account images and other media more than ever before) improving your overall search engine optimization.

Try to name each image using keywords that link to the subject of the page that the image is on. If the subject of your page is red flowers, then find an image of a red flower and name it red-flower.jpg. Hyphenate the image names or use underscore between the words. The search engine spiders will see this image name as separate words if you do this.
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, k# R% ~% u. o: E$ Y* lDon't be tempted to abbreviate your image names, thus rendering them unrecognizable for SEO purposes e.g. rdflwr.jpg. You may end up with rather long image names by using the full keyword names but you will maximise the SEO benefits of your chosen key phrases for each page.
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( d# \! Q+ a( t, i5 S; kLastly vary the image names that you use, when you have multiple images on one page, even by one letter to make it a plural e.g. red-flowers.jpg or flowers-red.jpg so that the search engines don't penalise you for keyword loading.
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3. Make sure you add alt tags to every image, which are also taken into account by the search engine spiders, once again using appropriately varied keyword phrases that link to the subject of the page.
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2 t; G6 j  J" j& Y4. Search on the Net for royalty free stock picture libraries. There are many of them, some specialising in one subject others covering a huge range of subjects. They are normally free to register with and generally use one of two payment systems: a credit system whereby you purchase x number of credits and each image costs a number of credits according to size; or a monthly subscription which allows you to download a certain number of images each month. Most libraries provide web ready images at 72 dpi or print ready images at 300 dpi. Web ready images are generally from 450-800 pixels wide or high, but this is perfectly adequate for use on a website. With prices often ranging from $1 per web ready image to $50 for a A4 sized print ready image this is a very affordable way of enhancing your web site and attracting both spiders and surfers.
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About the Author
% E/ ~# m4 O7 R  s0 [4 l- h8 {Patrick Heath**** is a photographer and web developer. Co-creator of A FlowerGallery.com - an online art gallery and flower picture library, he has also recently launched a luxury travel website JustthePlanet.com and maintains several other websites including Food-and-Family.com

不錯。好像Google的網管中心也有提及。