SCIWRIT

Database to SCITEX HandShake Disk File

Environments	MODELER EASI
Batch Mode	Yes
Sections	Description Ports Port Details Parameters Parameter Details Details

Description

Transfers image data held in a PCIDSK database file to an SCITEX Continuous Tone Picture (CT) format file.

Ports

In/Out	Name	Caption	Type	Min. - Max. Layers	Connection
In	Input	Image PCIDSK Layer(s)	Raster	1 - 3	Mandatory
In	InputLUT	Lookup Table Layer(s)	LUT	0 - 3	Optional

Port details

Input: Image PCIDSK Layer(s)

Contains the input image PCIDSK layer(s).

InputLUT: Lookup Table Layer(s)

Optionally contains Lookup Table layers.

Parameters

Name	Caption	Type	Data Range	Default	Optional
OutputFile	Output Filename	Text	<filename, max. 64 characters>	<none>	No
SciSize	Size of Output Map (mm/cm/inch): Width, Height	Text	<string, max. 64 characters>	<none>	No
SciSepar	Separations	Text	C,M,Y,K,CMY,CMYK	C (Cyan)	No

Parameter details

OutputFile: Output Filename

Valid Values: <filename, max. 64 characters> Default value: <none>

Specifies the name of the SCITEX format file to be created to hold the output imagery.

SciSize: Size of Output Map (mm/cm/inch): Width, Height

Valid Values: <string, max. 64 characters> Default value: <none>

Specifies the size (width,height) and units (mm/cm/inch) of the image:

SciSepar: Separations

Valid Values: C,M,Y,K,CMY,CMYK Default value: C (Cyan)

Specifies the separations which should be written to the SCITEX CT file.

If a single layer is provided, then it can be written as a C, M, Y, or K (Cyan, Magenta, Yellow or Black) separation.

If three layers are provided, then they can be written as CMY or CMYK separations.

Details

SCIWRIT creates a SCITEX Continuous Tone (CT) format Picture file (FILO) from imagery contained in a PCIDSK database file (FILI). The created CT file is usually then passed to a SCITEX system for printing.

One or three PCIDSK image channel(s) (DBIC) may be converted to SCITEX format file at a time. An enhancement can be applied to the image channels as they are written to the CT file using Lookup tables (DBLUT).

SCISEPAR specifies the separations desired. For single channels, there can be a single separation: C, M, Y, or K (Cyan, Magenta, Yellow or Black). For three channels, either CMY or CMYK separations can be written.

Note: if CMY is specified, then four separations are still written to the CT disk file, however the K (black) separation is uniformly set to the value 255, which indicates no black.

SCISIZE specifies the size of the final printed image.

The algorithm conversion for RGB to CMY is given below:

   Cyan    = Red   
   Magenta = Green
   Yellow  = Blue
   Black   = 255

The algorithm conversion for RGB to CMYK is given below:

   Black   = maximum (red, green, blue)
   Cyan    = Red   + 255 - Black
   Magenta = Green + 255 - Black
   Yellow  = Blue  + 255 - Black

FILE FORMAT

SCIWRIT creates a SCITEX Continuous Tone (CT) picture file on disk. The layout of the file matches the Floppy Diskette format described in the 'HandShake Foreign File Transfer Protocol' manual available from SCITEX Corporation.

A quick overview of this format is shown below:

              +-----------------+ 
              |  Control Block  | 256 bytes
              +-----------------+ 
              |     Unused      | 768 bytes
              +-----------------+ 
              | Parameter Block | 256 bytes
              +-----------------+ 
              |     Unused      | 768 bytes
              +-----------------+       
              |     Row 1       |               
              +-----------------+               
              |     Row 2       | Data
              +-----------------+               
              : :
              +-----------------+       
              |    Last Row     |       
              +-----------------+

The 256 bytes of the Control Block contain:

 Bytes       Field Name   Description

   1-80      NAME         File Name (Only 20 characters used) 
  81-82      FILE TYPE    'CT'
  83-94      DBSIZE       Data block size (always 1024)
  95-106     Reserved
  107        ICONT        Tape number (always 0)
  108-256    Reserved

The 256 bytes of the Parameter Block contain:

 Bytes       Field Name   Description

   1         UNITS        Units of measurement (0=mm)
   2         NUMSEP       Number of color separations (1 - 16)
   3- 4      EXSEP        Bit Mask of existing separation
   5-18      HEIGHT       Size of Image Data in Y- direction (UNITS)
  19-32      WIDTH        Size of Image Data in X- direction (UNITS)
  33-44      HPIX         Number of lines  
  45-56      WPIX         Number of pixels
  57         SCAN DIR     Scan Direction
  58-256     Reserved

The general pixel data organization is called "Line Interleaved" which means row after row in increasing Y order.

Within each row, each separation is contiguous. Separations are ordered: cyan, magenta, yellow and black.

If the number of pixels in the X - direction is odd, an extra 0 (zero) byte is added at the end of each separation within a row.