Version: 3.1
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The LEA Raster Object supports generic raster (graphics) file i/o in a variety of formats for LEA applications. The LEA Object interface is implemented by RASCOM.DLL. See The LEA Object for details of how to add other file formats, or attributes to the information read by default. Parts of the imaging technology within this object are copyrighted by Snowbound Software Inc.
The LEA Raster Object supports a large number of raster file formats through Snowbound Software's powerful RasterMaster DLL. The LEA Raster Object also provides backward compatiblity with Lynx's 3-S software by providing support for raster file types previously used by MS-DOS versions of 3-S.
When using older MS-DOS based 3-S programs, you will commonly come across four types of raster file: RLC, PLT, T30 and TIF
.RLC (Cad-Image format) files are simple, monochrome Run Length Coded files used as input to the vectorising process, in versions of SSV up to V21. In their original form, they have a minimal header containing only the number of rows and columns in the image. After processing by the old 3-S PREVU program, an .RLC file contains additional header information about resolution, Client etc and a row index table to speed access to the data. These modified .RLC files can still be read by most other applications, as the extra information is at the end of the file.
.PLT files are "raw", monochrome bit maps used for plotting on Versatec/Geospace compatible plotters. The image is stored as binary bits, with black dots represented by ones and white dots by zeros. Each raster line is a contiguous string of bytes, and the raster lines are stored in sequence from top to bottom of the image with no delimiters in between.
TRCPLOT and other 3-S programs which produce .PLT files generate a dummy raster line at the beginning of the image to contain header information for the plot spooler program VSPOOL. When plotted on other systems, this will produce an unobtrusive pattern of dots in the corner of the image.
.T30 files are in Scitex type 30 colour run length coded format. 3-S software had no colour capability, so colours 1 and 2 in the Scitex range are used to represent white and black. This file format can be used to transfer data to and from Scitex type 280 laser plotting/scanning systems, or applications which support this format.
TIFF stands for "Tag Image File Format" and is a standard covering a wide range of raster file types. The principal advantages of TIFF format are that a) it can be read by a wide variety of hardware platforms, including PCs, Suns and Apple Macs. and b) it supports a wide variety of image types including monochrome, greyscale and colour with or without palettes as well as several different compression schemes. In fact, you might well ask why there are literally hundreds of raster file formats out there, when practically everything you could ever want to do with rasters can be done with TIFF!
3-S programs under MS-DOS had their own TIFF read/write capability (bi-level files in uncompressed, "Packbits" and LZW compressed monochrome formats) through Lynx's TIFLIB. In Windows LEA applications, TIFF is handled by the Snowbound libraries, which support a much wider range of TIFF sub-formats.
Snowbound use an identifying number for each of the formats their library supports. These are mapped directly into the numeric format codes used by the LEA Raster Object. Lynx formats are given numbers 100 and above. Note that sub-formats supported within TIFF have individual numbers, 0, 7, 8, 9, 10, 16, 17, 40, 46, 47 and 50.
Code Description 0 Uncompressed TIFF 1 Uncompressed bitmap (BMP) 2 PCX 3 TARGA 4 Graphic Interchange Format (GIF) 5 WordPerfect metafile (WPG) 6 Windows MetaFile (WMF) 7 TIFF Huffman 8 TIFF Group 3 FAX 9 TIFF LZW encoded 10 TIFF Group 4 11 Intel DCX 12 BMP compressed 13 JPEG (JPG) 14 Adobe Encapsulated Postscript (EPS) 15 Apple Mac bitmap (PICT) 16 TIFF PACK 17 TIFF 2D 18 CALS 19 LASER DATA 20 X-Windows bitmap (XBM) 21 Apple MacPaint 22 GX2 23 KOFAX 24 IOCA 25 Microsoft Icon (ICO) 26 IFF ILBM 27 CLIP 28 Digital Research IMG 29 BROOK TROUT 30 Microsoft Paint (MSP) 31 CUT 32 TARGA16 33 CCITT G3 34 CCITT G4 35 X-Windows ASCII pixmap (XPM) 36 XWD 37 Sun raster format (RAST) 38 ASCII 39 Kodak PhotoCD 40 TIFF JPEG 41 Adobe Photoshop (PSD) 42 IMNET 43 Compuserve PNG 44 GIF interlaced 45 XEROX EPS 46 TIFF Arithmetic Binary Encoded grey-scale 47 TIFF Arithmetic Binary Encoded monochrome 48 Windows Device Independent Bitmap (DIB) 49 MODCA IOCA 50 TIFF G4 FAX FO 51 CCITT G4 FO 52 CCITT G3 FO 53 FLASH PIX 54 DICOM 55 JEDMICS 56 PCL 1 57 WINFAX
Raster objects have the following attributes:
Attributes are defined in the INI file RASOBJ.INI.
The default viewer for raster objects is the LEA Raster Viewer utility RASVIEW.
Unrecognised file type
This
message is generated when the opened file cannot be recognised as a format
supported either by Lynx or Snowbound libraries. See list of
supported file types.
The following messages are generated from Snowbound DLL function return codes.
Snowbound raster file open failure
Out of memory
Failed on memory
allocation. Problem with a standard memory allocation
File not found
Open call failed
when trying to decompress an image
Corrupted file
File format bad,
or unreadable. Usually returned when decompress function gives up on an image.
Bad string
String passed in is null
or invalid. May be returned in VBX/OCX products
Bad return
Internal VBX/OCX problem
Can't create file
Fail on
saving when attempting to create a new file. Also may be returned for .tif
planar images since a temp file must be created.
Format not allowed
The image
was not recognized as an image the SnowBound Software library can decompress
No bitmap found
Getobject function
call failed to return bitmap header for using DDB functions.
May also be
returned in formats that can contain vector information such as .wpg, .wmf and
.pct if no bitmap information is found
Disk full
Error writing data to the
disk. Standard file i/o write failed. maybe the disk is full.
Tried to display with negative coordinates or out of range
Page not found
Used for
multipage file format support when attempting to access a page which does not
exist
Disk read error
File format was
truncated and tried to read past end of file. Standard read i/o function failed
Bad handle
Application passed bad
image handle. Not a valid SnowBound library image handle
No clipboard image
Image not
found on clipboard
No scanner found
Twain scanner
driver not installed or not found (TWAIN.DLL)
Error opening scanner
Bad
scanner driver or driver not configured properly
Can't find TWAIN DLL
Twain
scanner driver not installed or not found (TWAIN.DLL)
User Cancel
Used for canceling out
of low level save or low level decompress. Usualy not an error but terminated a
function on purpose
Evaluation Timeout
The date on an
eval copy of product has expired
Using runtime
Vbx/ocx runtime
version not allowed for design mode
Pixel depth unsupported
Tried to save an image to format not supported the images bits pixel.Also tried
to perform an image processing function an an image whose bits per pixel is not
allowed
Pallette images not
allowed
Some image processing operations will not work on palette
images
No LZW version
No lzw code or
gif in this version
DLL not loaded
DLL not loaded
for platinum win3.1 version snbd6w31.dll
Format will not support on the fly decompression
No transparancy color information found
Currently not supporting this compression format
No more pages ready in document feeder
No more pages ready in document feeder
No delay time found
Couldn't find graphic extension block in .gif file
TIFF tag not found
Couldn't
find .tif tag
Not recognized as a TIFF tiled image
See also:
[The Lynx Exploration
Archive Object]