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 program is
located.
-
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 program is located.
-
Start AWeb, 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.
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.
MULTIPASS=0|1
- Specifies if interlaced PNG images should be rendered progressively.
MULTIPASS=1 (the default) will display interlaced PNGs in multiple passes,
each with increasing quality.
Use MULTIPASS=0 to disable rendering in multiple passes, and only display
the final image. This may be faster when reading from fast connections or
from local files. This also disables PROGRESS (sets to 0) otherwise
interlaced PNGs would still appear to decode in a multipass manner.
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
This distribution of AWeb comes with no support, however the AWeb Mailing list has many users and you are encouraged to subscribe if you haven't aleady done so.
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
Copyright © 2002-2007 by the respective contributers of The AWeb Open Source Project. All rights reserved.
Any code or files that remain in their original, unmodified form are
Copyright © 1998-2000 by Yvon Rozijn. All rights reserved.
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 1.9 (1-12-2000)
- Added support for scaling after completion, necessary for percentage scaling.
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)
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)