Known problems with certain formats
a) Grayscale Progressive JPEGs and CMYK JPEGs are currently not supported.
b) JPEG-TIFFs are not supported and probably will not so in the near future.
Since there are several flavours of this format, please
send us such a file, so we will be able to test our code on more examples.
c) Dr.Halo/Dr.Genius: This format has an unusual layout. The files do not
contain image dimensions (width and height). They just contain the ID of the
videoadapter they were created on. We do not have the full list of such IDs.
If PictView cannot read your images you made 10 years ago,
send us a few such pictures. We will send you back an updated version of
PictView within 48 hours.
d) Animated GIFs are a constant source of problems. Some of them may be
displayed with an inappropriate background color etc. If you send us such
pictures, we will consier their speciality for the next version of PictView.
e) Amiga IFF/ILBMs: There is no standard way of encoding images with odd
number of bytes per line. Therefore some images can have the "shift" effect or can
be misinterpreted. We work on a heuristic algorithm detecting the encoding.
e) Adobe Photoshop PSDs: If the file contains more than one layer, PictView
is able to load and display only the first layer found in the file. As a result,
some (or all) objects can be missing from the displayed image.
I get "Image too wide" error
This happens on very wide JPEGs, especially with subsamling 4:1:1. As a
workaround, try turning OFF the High Compatibility Mode (see the next question).
I get "Image too large! Only first X lines will be read" error
I love PictView for DOS. Will you continue to support it?
What's next?
PictView for DOS crashes when attempting to view an image on MS Windows
The image in the uncompressed form must fit in the memory (conventional DOS and XMS,
in total at most 19200 KB) and must have at most 5200 lines, otherwise it will
be loaded only partially.
Besides the standard ways of memory optimization (e.g. disk cache and RAMdrive
size decreasing), you can configure PictView to save extra 64 KB by turning
OFF the High Compatibility Mode. PictView then uses
VideoRAM as a buffer which is normally located in the DOS memory. However, this
mode does not work on some videoadapters, with some drivers on MS Windows etc.
Some users have also reported problems when reading images from floppy disks.
Generally, the overall speed performance will be decreased. To leave the
High Compatibility Mode run CfgPV.exe (or hit F7 when running PictView)
and set 'High Compatibility Mode' on the main screen to 'No'.
We pesonally hate slow programs occupying megabytes (or gigabytes) and requiring
1 GHz Hexium (or a similar CPU). We also hate keeping 128 utilities for
comfortable work with 20 basic file formats we usually encounter in daily work.
In our opinions, PictView meets these criteria. PictView is written mainly
in assembler and it runs on any 386 machine with at least 1 MB of RAM and a VGA
adapter. We have started porting PictView to MS Windows (both 16bit and 32bit),
but we do not plan abandoning further development and support of the DOS
version. However, if we stop receiving feedback in long range (see also
sponsoring the project), we will stop its development.
In the near future: Grayscale Progressive JPEGs.
We are considering: Support of JPEG-TIFFs, playback of AVIs, "inteligent"
selection of transparent color when saving a GIF, creating PNGs, support
of MNGs (Multiple Network Graphics, "animated" version of PNG), improved
"effects" in the F8 menu and their support on the command line, preview.
We are not considering: support of sound, playback of MPEGs.
I get "Image too large! Only first X lines will be read" error on MS Windows
By default, MS Windows don't provide more XMS memory than 1 or 2 MB. This may
be insufficient for large images. We suggest you to create a shortcut (or
a PIF file in case of Win3.1; in fact, a shortcut is represented by a PIF
file). Specify a specific amount of memory you think would be engough. Just
start with 2 MB and if PictView still complains, increase the value and restart
PictView.
Some video drivers for MS Windows 95/98/2000 under some circumstances do not allow
DOS programs to use any SuperVGA mode. In some cases, the drivers crash the
system in such a way that a hard RESET is needed.
MS Windows NT from their nature do not allow DOS programs to use anything
else than the standard VGA modes. If you start PictView full screen, VESA BIOS
can be detected, however attempt to use VESA modes may lead into hard crash
of the system, when a hard RESET is the only solution. We are sorry, but we
cannot do anything about it.
I cannot load PictView for DOS on OS/2, it crashes on runtime error 200
It seems that OS/2 has some problems in implementation/emulation of VESA BIOS.
As a result, PictView (and ShowJPG) can crash at startup by runtime error
on address Ayyy:yyyy or Byyy:yyyy. These addresses are invalid and are not used by PictView.
PictView starting with version 1.93 bypasses a greedy algorithm detecting
available display modes, if OS/2 is detected. We do not have an OS/2 machine,
so we cannot test it. Users of OS/2, please report
behaviour of 1.93 and later versions on OS/2.