AWeb PNG plugin

General

The awebpng plugin for AWeb allows you to view all PNG images. Features include:

Optional progressive display of loading images
Support for transparent images
Support for scaling
Support for CyberGraphics

Installation

Follow these steps to install the AWeb PNG plugin.

Run the supplied Installer script. It will copy the necessary files to a drawer awebplugins in the drawer where the AWeb-II program is located.
Run the .

Manual Installation

If, for some reason, you don't want to install the plugin automatically, you can install it by hand.

Copy the file named awebpng.awebplugin to a location of your choice. The recommended location for plugins like this is a drawer awebplugins in the drawer where the AWeb-II program is located.
Start AWeb-II, open the browser settings and bring up the Viewers page. Select the entry for MIME type IMAGE/PNG and change the following settings:
- Action: "AWeb Plugin (A)"
- Name: the location where you copied the file awebpng.awebplugin
- Arguments: leave blank or supply optional parameters, see below
Don't forget to save your settings.

Parameters

The awebpng plugin supports two optional parameters. You can type the chosen parameters in the "Arguments:" field of the settings window. Separate the parameters by a comma or space, if you specify more than one.

PROGRESS=0|number

Specifies the number of image scan lines to decode before the display is updated. A higher number is faster but results in chunkier building of the image. PROGRESS=1 gives the smoothest progressive display but is relatively slow. The default value is 4, which is a good compromise between speed and visual attractiveness.

If you specify PROGRESS=0, progressive display is disabled. The image is not displayed until decoding is ready.

GAMMA=number

Specifies the gamma colour correction factor for your configuration. It is usually a number in the range 1.0 through 2.5. Default is 2.0.

LOWPRI

The LOWPRI argument will run the decoder at a lower priority than default. If you are using your Amiga for other tasks while AWeb is downloading images, this feature helps you to keep the GUI responsive when many images are being decoded. However, if you are running CPU intensive tasks this argument could stop images from being processed alltogether.

Note that the LOWPRI argument might not be effective when you use a custom task scheduler like Executive. Use task name "AWebPng decoder" to configure the decoder task in custom schedulers.

Support

The AWeb PNG plugin was written by the author of AWeb-II. Any questions, comments or bug reports can be addressed to Yvon Rozijn <yrozijn@xs4all.nl>.

Disclaimer

This software is provided "as is". No warranties are made, either expressed or implied, with respect to reliability, quality, performance, or operation of this software. The use of this program is at your own risk. Yvon Rozijn assumes no responsibility or liability for any damage or losses resulting from the use of this software, even if advised of the possibility of such damage or loss.

Copyright

The AWeb PNG plugin is copyright © 1998 by Yvon Rozijn.
It uses the PNG reference library that was written by Guy Eric Schalnat, Group 42, Inc., Andreas Dilger, Glenn Randers-Pehrson.
It also uses the ZLIB general purpose compression library that was written by Jean-loup Gailly and Mark Adler.

History

awebpng.awebplugin 1.8 (5-9-1999)

Cleaned up the code a bit.

awebpng.awebplugin 1.7 (1-5-1998)

No longer uses chip memory if CyberGraphics is used.

awebpng.awebplugin 1.6 (19-10-1998)

Added support for proportional scaling (only one of WIDTH and HEIGHT specified).

awebpng.awebplugin 1.2 (01-03-1998)

Added LOWPRI argument.

awebpng.awebplugin 1.1 (25-02-1998)

Removed possible decoder stalls.
Much faster progressive display of scaled images.

awebpng.awebplugin 1.0 (22-02-1998)

Initial version