HamLab Version 1.1c
(c) Copyright 1990, 1991 J. Edward Hanway

FILE TYPES SUPPORTED

GIF (Graphics Interchange Format)

   GIF versions GIF87a and GIF89a are both supported.
   
   Non-interlaced GIF files require much less memory to convert than
   interlaced GIF files. NOTE: This "interlace" has nothing to do with
   the Amiga display.  An "interlaced" GIF file stores the lines of the
   image in scrambled order, rather than top-to-bottom, so that, in theory,
   you can see the overall picture sooner while it is being displayed.
   Most GIF files are not interlaced. 
   
TIFF (Tag Image File Format)

   Supports black&white or gray scale images with 1, 4, or 8 bit planes.
   
   Supports RGB color images with 3, 12, or 24 bit planes.
   
   Images must either be uncompressed or use PackBits compression (type
   32773).

SPECTRUM 512

   Normal, compressed (.SPC) files supported. Uncompressed (.SPU) and .SPS
   files are not supported.
   
PBMPLUS

   Black&white (PBM), gray scale (PGM), and color (PPM) files are all
   supported.  Both ASCII and RAW (binary) formats are supported.
   
MTV

   The RAYSHADE ray tracer by Craig E. Kolb can also write images in this
   format.
   
QRT, DKBTrace

   Although both the QRT and DKBTrace ray tracers use the same file format,
   QRT uses only 21 bits of information per pixel while DKBTrace uses 24
   bits.  With default settings, DKBTrace pictures will look correct, while
   QRT pictures will be too dark, but this can be compensated by increasing
   the brightness.  (The easiest way to do this is to load the color
   control settings from the "QRT_color_response" file.)
   
SUN RASTERFILES

   Black&white, 8-bit mapped color, and 24-bit color images are supported.
   Both uncompressed and run-length compressed raster files are supported.
   
IFF ILBM

   Reads nearly all IFF Interleaved Bit Map images:
   
   - Normal, color-mapped with 1 to 8 bit planes
   - HAM
   - SHAM
   - Halfbrite
   - 24 bit
   - Dynamic HAM
   - Dynamic HIRES
   - HAM-E REG mode
   - HAM-E HAM mode
   
Truevision Targa

   Reads file types 1, 2, 9, and 10, with 16, 24, or 32 bits per pixel.

JPEG

   This filter reads "JPEG Interchange Format (JFIF)" files.  JPEG files
   can be use two kinds of compression: Huffman coding and arithmetic
   coding.  Because supporting arithmetic coding would require licensing
   a patent from IBM, it is not supported.  (Probably for this reason,
   Huffman coded JPEG images are much more common.)
   
   Note that JPEG requires extensive calculations to decompress a picture.
   Don't panic if your Amiga doesn't seem to be doing anything at first.
   
Windows Bitmap

   Reads uncompressed .BMP files with 1, 4, 8, or 24 bits per pixel.  RLE
   compressed 4- and 8-bit files are not supported.
   
"Special" PBMPLUS

   This filter is a trick program that can be used to convert from any
   format supported by the PBMPLUS toolkit directly to HAMLAB.  It
   requires AmigaDOS 2.0.
   
   ** This filter is sort of a hack.  It requires you to obtain the
   ** PBMPLUS toolkit (available from many sources such as BBS's) and
   ** set things up with the correct names and assignments.  In order
   ** to get things set up successfully, you should be familiar with both
   ** HAMLAB and PBMPLUS, as well as the Amiga CLI.
   **
   ** Because this is very dependent on other programs and installation
   ** details, I can't guarantee it will work in all situations.
   ** It may also have problems handling errors gracefully.
   ** For file formats supported by regular HAMLAB filters, this filter
   ** should not be used.

   Requirements:
   
   * AmigaDOS 2.0x only
   
   * The PBMPLUS toolkit.  You should install the PBMPLUS programs in
     a separate directory, then use the Assign command to assign the name
     "PBMPLUS:" to that directory.
     
   * The "special2hl" program must be placed in the HAMLAB filters
     directory (the one specified in the hamlab.config file).  However,
     it should be named "XXX-2hl"  Replace XXX with the same abbreviation
     that is used for the PBMPLUS program that you with to run.  For
     example, if you want to use the PBMPLUS program named "giftoppm" name
     the copy of special2hl "gif-2hl"  Note the dash before the 2.  It
     must be there.
     
   * Use a text editor to add an entry into your hamlab.config file.  It
     should use the "XXX-2hl" name you chose in the last step.

   The way this works is the "special2hl" program looks at the new name you
   gave it.  It takes the part before the dash, and uses it to find the
   correct PBMPLUS program to run.  If it is named "XXX-2hl" it will try
   to look for the following programs, in order:
   
     PBMPLUS:XXXtopnm
     PBMPLUS:XXXtoppm
     PBMPLUS:XXXtopgm
     PBMPLUS:XXXtopbm
     
   Example for GIF files: **EXAMPLE ONLY -- YOU DON'T **
                          **NEED TO DO THIS FOR GIF   **
   
   1. Assign PBMPLUS: to the directory where you put the PBMPLUS
      programs.
      
   2. In your HAMLAB filters directory, make a copy of the "special2hl"
      program.  Name it "gif-2hl".
      
   3. Add the following line to your hamlab.config file:
   
      Format "GIF" "gif-2hl"
      
   4. That's it.  When the filter is run, it should look for the program
      "giftoppm" in the PBMPLUS: directory.

   If the PBMPLUS program displays any messages a console window will open
   to display them.  Click the close gadget on the console window to
   dismiss it.
   
ACKNOWLEDGEMENTS

   The Graphics Interchange Format(c) is the Copyright property of
   CompuServe Incorporated.  GIF(sm) is a Service Mark property of
   CompuServe Incorporated.
   
   Rayshade ray tracer by Craig E. Kolb.
   
   MTV ray tracer by Mark Vanderwetting.
   
   QRT ray tracer by Steve Koren.
   
   DKBTrace ray tracer by David K. Buck.
   
   PBMPLUS by Jef Poskanzer.

   The JPEG filter is based on work by the Independent JPEG group.
   
   Targa is a trademark of Truevision, Inc.
   
   Windows is a trademark of Microsoft, Inc. (Formerly Traf-O-Data)