Images

Changing Format

Image Formats | Creating Images | Changing Format | Transparent Backgrounds | Background Tiling | Animated GIFs | Image Resources | Screen Captures | Going Further

Although the newer versions of Internet Explorer can display inline images in the BMP format, some earlier versions did not. Netscape still does not display this format inline, but instead launches a helper application to show the figure. Consequently, if you have images in this format and you want to make sure that the widest possible audience can view your images as integral parts of your web pages, you should convert the files to either GIF or JPEG format. There are many graphics programs that can perform such conversions. Such conversion is, for instance, a feature of high-end programs such as Adobe Photoshop. But the conversion can also often be accomplished with much less expensive software, some of which may come bundled with your computer.

A program in the latter category may be the Microsoft program Paint which is included as one of the accessories with the Windows operating system software. (We say "may" because while versions of the program available with Windows 98, and newer versions of the operating system, allow you to save files in GIF and JPEG formats, under some older versions of Windows Paint only allows you to save in BMP format.)

To access the program, select Programs, then Accessories, and then Paint. The opening screen will look like this:

As an example of format conversion with Paint, we'll first create a simple image with the program, save it in BMP format, and then close the file. Then we'll re-open the file in Paint and convert the image to a JPEG. (Of course, we could just save our artwork as a JPEG to start with. But we'll use this round-about approach here just to illustrate the conversion process, which can also be used to convert files that you may have obtained elsewhere and for which had no control over the initial format.)

Creating a Bitmap Image (if necessary)

Before we can convert a bitmap image (.bmp) to a JPEG image (.jpg) or GIF image (.gif) we need a bitmap image. If you don't have a bitmap image, you can create one in Paint by following these steps.

1. You already have a new file open, so click on the paint jar icon from the tools menu.

2. Then select (click) on a color of your choice from the color menu located in the left corner.
   

3. Go back to your white background. The cursor should be a paint jar and by clicking on the white area, it should turn a different color.

4. Now click on the spray can icon from the tools menu.

5. Select a paint color such as white from the color menu.

6. Place the spray can cursor over the background color and by holding down the left mouse scrawl some graffiti of your choice.

7. You should have something that looks like this:

   

8. Now you have a bitmap image file you can convert by saving the file.

   
   

Convert from Bitmap to a JPEG

(Recall that in some older versions of Windows-- e.g., Windows 95 and Windows NT--Paint will not allow you to save files in anything but BMP format. Consequently, with these older systems the following format conversion scheme will not work.)

Converting a Bitmap image to a JPEG image is as easy as saving the file again. As a matter of fact, that is all you do:

1. Re-open Paint if necessary and open up the file loveschool.bmp. Your graffiti artwork will fill up the work area.

2. You can add some more graffiti spray paint and then save the file again EXCEPT this time instead of saving it as a .bmp, use the Pulldown menu next to "Save as Type" and reset the format as "JPEG File Interchange Format (*.jpg, *. jpeg,) and rename the file as "loveschool2."

   

3. Now you have JPEG you can use for your web page.

More About Bitmaps and JPEGs and Conversion

There are several other things you should now about changing formats:

• Bitmap image files are large files (that can fill up a hard drive). On the other hand, JPEGs are compressed images. For example, loveschool.bmp file size is 577 k and the loveschool2.jpg is 23K.

• Converting a bitmap image file to a GIF (.gif) file follows the same procedure, except you save the file as a "Graphics Interchange Format (.gif)".

• Once you convert an image to a JPEG or a GIF, much of the "information" is lost about the picture. This is normal. Remember these formats are designed to compress information. However, once it is compressed and saved you cannot return to the original image. That's why it is a good idea to make a copy of the file before changing formats.