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they are a lossless form at, meaning no information is thrown away in compres sion.
JPEG (or JPG) images work best for photos—images with a lot of different co lors and no text. JPEG images can
represent a lot m ore co lors than GIF (16 millio n instead of 256 ), so yo u'll get richer co lor. JPEG is a lossy format,
meaning that when you compress images, you lose so me info rmation. However, for the web, it's unlikely anyone will
notice unless they're viewing yo ur images at very high resolution, which isn't advised anyway becaus e the im ages
would be so large. JPEG does not support transparency, so you aren't able to use them like GIFs to create effects
where you see the background behind the image.
PNG is an image format that was designed to be a better version of GIF. The format is best us ed where you'd use a
GIF—it s upports transparency and represents lines and text well—but also can repres ent a lo t more colors than GIF.
Be careful when using PNG tho ugh, because PNG images tend to be large as a result of their greater depth o f color
(you may want to stick with JPEG for photos).
When yo u save an image for the web, it's a goo d idea to save the image in the size yo u plan to use o n the page. So,
for exam ple, do n't save an image at 80 0 pixels wide by 600 pixels high if you know yo u'll only need a 200x150 image
on the web page. You can reduce the file size o f an image by reducing its width and height. This reduction is s ize also
means your images will load faster!
Uploading Images to Your OST Account
Note
As you work through the next sectio n, if you decide to use an image other than the one we've provided,
be s ure to choose an image that do es not violate copyright laws. A quick s earch fo r public domain
images or creat ive comm ons im ages s hould do the trick!
You can display images from o ther locations o n your o wn page by linking to them using abso lute URLs. You can als o
upload images (or any other file that is saved o n your computer) to yo ur OST account, and link to them using relative
URLs instead.
Let's save an im age that we can then upload to your account. Right-click on the image of the dog (Tilla) below and
you'll see the same menu from before. Select S ave Im age As/Save P ict ure As and save the image to your
computer (make a note of the lo cation where you save it).
Next, select your /ht mlcss1 folder and click File | Add in the CodeRunner® File Bro wser window o n the left: