JPEGView  -  JPEG image viewer

by Alan Wrigley


JPEGView demonstrates the techniques of displaying JPEG images as described in the Wimp Topics article in this month's RISC User magazine.

Running the application installs an icon on the icon bar. You can now drag a sprite, JPEG or GIF file to the icon bar icon, and it will be displayed in a window. If your computer can handle JPEG files natively (i.e. you have SpriteExtend 0.99 or greater) then JPEGs will be displayed instantly using the new JPEG SWI calls as described in the article.

By default all images are displayed at their original size. However, the application also demonstrates the techniques of scaling. The icon bar menu has an entry entitled Options which leads to a dialogue box. From this box you can choose whether to display the image at the original size, or to display it at a specified size. If the latter, you can also choose whether to maintain the original aspect ratio or not.

If you select the specified size option, two writable icons allow you to enter the required size of the image (in OS units). There is also a further option button which allows you to specify whether to maintain the aspect ratio. Clicking on OK in the dialogue box activates the choices, and if an image is currently being displayed, its format will change to match the choices you have made.

For further information on all these techniques, you should read the Wimp Topics article referred to above.

 Copyright RISC User Magazine 1997
