HTML Goodies
Navigation Links
----- Goodies to Go!

Now you can
get Goodies by
e-mail too!
-----
Navigation Links
tabs

Basic HTML Primer #6--Manipulating Images

Basic HTML Primer #6
Manipulating Images

by Joe Burns, Ph.D.
...Use these to jump around or read it all

[Placement On The Page][Aligning Text With Images]
[Changing Image Size][The <HR> Command]

 

      Just as I thought a primer, Primer #3, was required explaining how to manipulate text, I also think one is needed on how to manipulate images. Believe it or not, manipulating images is easier than manipulating text. So, here we go.


Placement On The Page

      First let's worry about placing the image somewhere on the page. The default is justified to the left. If you write an image flag on a page, the image will pop up hard left.

      If you want to have an image placed in the center of the page, you might be able to guess at this point that you'd use the <CENTER> and </CENTER> commands described in Primer #3.

     But how do we get the image to the right of the page? Well, how did we get text to the right? By adding the attribute ALIGN="--" to the <P> command, right? Could it be we do the same thing here? Why yes, it could.

Here's the format:

<IMG ALIGN="right" SRC="image.gif">

Here's what you get using "sally.gif" in place of "image.gif":


Aligning Text With Images

      Images don't always stand alone. You will often want text along side of them. Here you will ALIGN text along the top, the middle, or the bottom. Again, you'll use the ALIGN="--" attribute with one of these three: "top", "middle", or "bottom".

Here are the formats:

<IMG ALIGN="top" SRC="sally.gif"> text text text

<IMG ALIGN="middle" SRC="sally.gif"> text text text

<IMG ALIGN="bottom" SRC="sally.gif"> text text text

And here's what it all looks like:

This is text ALIGN="top"

This is text ALIGN="middle"

This is text ALIGN="bottom"

     You may notice that using the top, middle, and, bottom attributes only allows for one line of text and then the rest jumps down below the image.

     Here's the trick to solving that. Don't use the top, middle, or bottom attribute unless you only want one line of text. If you want text to wrap around the image, use ALIGN="left" and ALIGN="right".

     Even if the image is already to the left, use the ALIGN="left" attribute anyway. It allows the text to wrap around the image fully. Try it, it's quite a clever little deal.

Two At Once?

     But what if you want only one line of text to come out of the middle of the image, and you want the image aligned to the right? Can you use two ALIGN="--" attributes in the same image? No.

     You set the text coming out of the middle using the ALIGN="middle" attribute in the IMG flag. Then you set the image and it's text to the right by surrounding the two items with the <P ALIGN="right"> and </P> commands.

     Are you starting to see how a flag does only one thing? If you want two effects placed on one items, you're going to have to use two different sets of flags.


Changing Image Size

      To begin this discussion, let me state that images on a computer are not like photographs. Computer images are made up of a lot of little colored dots. They're known as picture elements, or "pixels" for short. So, just remember that during this part of the Primer, numbers refer to pixels rather than inches, or centimeters, or whatever. When I say pixels, I'm talking little colored dots.

     Every image is made up of pixels. The more pixels per inch the image has the better, and more detailed, the image will appear. Of course, that also means the image will take up a whole lot more bytes on your hard drive. You're going to find that most images on the Web are 72 and 100 pixels per inch. Yes, there are other settings, but 72-100 is a good trade off between loss of detail and bytes required.

     OK, so every image is made of pixels. This means that you can also denote an image by number of pixels. For example, the "sally.gif" image is 97 pixels high by 64 pixels wide. How do I know that? I have an expensive graphics program that tells me so. How would you know? Without a specific program, you wouldn't. You'll have to play around with the numbers in these commands a little bit but it's easy to do.

      You might also want to open the image by itself in the Netscape Navigator browser window. Do that by choosing "OPEN FILE" under the FILE menu. When the picture pops up, look at the title bar along the very top. the height and width should be there.

     Of course you can also go out onto the Web and surf around for a shareware graphics program. My personal favorite is Paint Shop Pro. You get it for free for 30 days and then it's like $80 or so to get it for good.

      Here's what you do. Denote to the image command how many pixels high by how many pixels you want wide. The "sally.gif" image is 64X97 pixels. If I want the image to appear smaller, I will ask for the pixels to be smaller, say 30X55. If I want it bigger, I would set the pixels larger, say 100X250. Just remember form. If you make the image smaller or larger, you must keep the same general square, rectangle, or whatever, form. Of course, if I want to, I can totally distort the picture.

Here's the coding:

<IMG HEIGHT="##" WIDTH="##" SRC="image.gif">

      Notice the HEIGHT and WIDTH attributes nestled right where the ALIGN command went before. You will replace the "##" with a number of pixels for height and width. Here are the three examples:

This is normal size:

This is 30X55:

This is 100X250:

This is 100X23:


The <HR> Flag

     The WIDTH command also works on the <HR> command, Except! You'll use percentages. Watch this:

<HR WIDTH="40%"> gives you this:


<HR WIDTH="64%"> gives you this:


You get the idea, yes?

      That wraps it up. Try these in the comfort of your own home under the supervision of an adult. If you are an adult, then find a kid who can program the VCR to help you along.

 

On to Primer #7

Back to the HTML Goodies Home Page

[Placement On The Page][Aligning Text With Images]
[Changing Image Size][The <HR> Command]

Handsome guy, huh?


Click here for more info

Master List of Goodies

Goodies Tutorials


Click here for more info


HomeAbout UsSearchSubscribeAdvertising InfoContact UsFAQs
Use of this site is subject to certain Terms & Conditions.
Copyright (c) 1996-1998 EarthWeb Inc. All rights reserved. Reproduction in whole or in part in any form or medium without express written permission of EarthWeb is prohibited.