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»PPT the 2nd
On the way from "crash king" to master of image manipulation
The modular image processor PPT by Janne Jalkanen
When PPT was tested for the first time in AmigaAktuell in late summer of 98, the judgement was devastating, due to the many crashes: "If you like russian roulette, you will love image processing with PPT. ... In its current state I won't entrust my pictures to PPT." [1] In the meantime, the Amiga community has entered the year 2000, Amiga got a new owner and PPT an intensive overhaul. A good reason to evaluate PPT again, with special regard to its usability and stability. You can find PPT in Aminet [2] and the latest version on the homepage of the author [3]. For this test, the latest version 6.18 "Descartes-2" was used.
Installation and system requirements
The installation is without any difficulties (as it was always). The AmigaOS installer quickly copies all necessary files to the correct positions.
The system requirements of PPT are still quite moderate. AmigaOS 2.0 with 1 MegaByte RAM and a few MegaBytes free harddisk space for virtual memory is enough to get the program to work. Convenient working starts at OS 3.0 (V39+), an Amiga equipped with AGA or a graphics board, at least a 68020 CPU and as much Fast RAM as possible.
Because the user interface uses the (included) bgui.library, MUI is not needed.
Usage
In principle, you can operate the program intuitively without reading the extensive english manual in AmigaGuide format. If you want to make use of all features of the program, you will find many tips and hints in the supplied documentation, which contains besides the description of all elementary program functions, also guide files about the ARexx port, the loader- and effect-modules and a short tutorial.
PPT greets the Amigan during the start process with a tremendous intro.
After the first start, you should use the "Preferences" menu entry to make some basic settings like display mode and location of the virtual memory. The default for the latter is "T:".
If the Amiga has a lot of Fast RAM, you can keep it so, in any other case you should rather choose a harddisk (partition) with enough space. The use of virtual memory makes it possible to use very big pictures and a theoretically unlimited undo function (practically only limited by the available space for virtual memory). This means a remarkable easier usage and a reinsurance against screwing up your pictures.
While exploring the preferences, some new features catch the eyes. Under "GUI" you can choose a colored preview for certain effects in variable size, and under "Toolbar" you have the option to configure a toolbar for your individual needs with your favourite functions.
Furthermore you can choose if PPT shall display tips at the end of the startup. PPT can open its screen in 8, 16 or 24 bits color depth, and can (independent from the choosen display depth) process pictures up to 24 bits (8 bits greyscale) with an optional alpha channel while multitasking internally.
The included modules can load many different picture formats, like BMP, IFF-ILBM, Targa, JFIF/JPEG, GIF, PNG, PNM/PGM/PPM/PBM, PsionPIC, YUVN and TIFF. If this is not enough, it can also load every format supported by DataTypes. For example EPS and PCX files loaded without problems, and the JPEG and GIF loaders, which were critized in the first test, because they the tended to crash very often and were almost unusable, now work as expected.
Many effect modules, which have been extended since the version tested in [1], are available for image manipulation. Many modules now have a realtime preview function with variable size. This makes it possible to work very intuitively with the different effects and to estimate the results. And the results look very good. Among the new effects, "Twirl" is standing out. As the name says, it can twirl (a part of) the picture. "ColorCount" determines how many colors are really used in a picture. Under the menu entry "Window/Select" waits another interesting new feature: In the new program version, you can limit the area where an effect takes place not only as a rectangle, but also as a circle or a freely defined area. This results in a much more flexible processing of desired picture parts.
he scripts have been reworked and extended, too. With the "BatchProcess" ARexx-script, you can apply effects like brightness or gamma adjustments, text-entries and a lot more automatically to whole series of pictures. The ARexx port leaves much room for your own scripts.
Furthermore, you can always display the current picture with correct proportions using the menu entry "Correct aspect". werden.
The effects, which were in earlier versions very likely to crash, have noticeably gained stability. Generally, the endless crashes of older version seem to be past now. When PPT takes a "time out", which happens seldom, the operating system didn't tend to go down too, during the whole test phase. The mean time between crashes seem subjectively not to be worse than with commercial programs like ArtEffect or Photogenics.
Finally the modules "Scale" and "Composite" work as they should, and "Bitfield" doesn't provoke an inevitable pause anymore. The combination of several picture with the "Composite" effect is now really possible and is fun, thanks to the drag&drop support.
Before saving pictures, the user is warned if he tries to overwrite existing pictures with the same name. Pictures can be saved in the formats BMP, C-code, ILBM, JPEG, PPM, PsionPIC and Targa. For most formats, extended parameters can be set. For instance, when saving JPEG, you can define the compression factor, whether to optimise, and whether to save a progressive JPEG.
Two intersting additional modules are available from the PPT-homepage in the "PPT_security.lha" package. The first one, "embedfile.effect", lets you invisibly embed a file, no matter if picture or text, into an existing picture. So you can hide a (password protected) secret information inside a picture. The second module, "extractfile.effect" can (after entering the correct password) extract the hidden information from a picture and make it readable again. Possible uses could be: An individual "water-sign" for your own pictures or the hidden transmission of confidential information. J. Jalkanen explicitely writes on his homepage that the usage of these (at least partly) cryptographic modules can lead to legal problems in some countries.
Although PPT is available free of charge, and because of this, you are not entitled to any kind of support; Janne Jalkanen is very interested in the opinion of the PPT-users any likes to help when problems arise. You can subscribe to a special PPP-mailing list on the PPT-homepage [1] or contact it on [4].
Result
The dramatically improved stability (compared to version 4.48, tested in AmigaAktuell 9/98) of the new version 6.18 "Descartes-2" makes it possible to work seriously with PPT, even though Janne Jalkanen describes this version as "beta".
With the usual precaution (which is also needed for other programs) your can start manipulating your pictures without fearing that the next operation will push your composition into the data-nirvana.
PPT has with the current version 6.18 "Descartes-2" finally left the childhood and is now a full grown, solid piece of freeware software. In Janne Jalkanens words: Another one megabyte the dust.
[1] Amiga aktuell, Ausgabe 9/98, Bildbearbeitung PPT [2] Aminet unter /gfx/conv/PPT_dist.lha [3] http://www.hut.fi/~jalkanen/PPT.html [4] http://www.egroups.com/list/ppt-list/
Uwe Pannecke <Uwe.Pannecke@t-online.de>«
