Pagebuffer file headers

This page applies to Harlequin v13.1r0 and later; and to Harlequin MultiRIP but not Harlequin Core.

Some parts of the pagebuffer header are device-specific, either in the values allowed or required for certain fields, or in the presence or absence of fields in the plugin parameter dictionary, if it exists (see Plugin parameters). This means that some knowledge of a plugin is required in order to generate pagebuffer files directly suitable for that plugin.

In particular, pagebuffer files suitable for one device may not be suitable for another device.

The easiest way of checking at least which fields are required and establishing default values for them, when the information is not directly available, is to produce a pagebuffer file in the RIP with the appropriate device selected and use it as an example.

Having written a pagebuffer, the easiest way of checking the correctness of the raster and relevant parts of the pagebuffer header (that is, the non-device specific bits) is to put it into the Output Controller and use Roam.

Example:

Here is an example header from a pagebuffer file with a version 20 header:

TEXT

            /PGB <<
            /PageHeaderVersion 20
            /HighByteFirst false
            /BandHeight 201
            /BytesInLine 2448
            /BytesInBand 492048
            /TrimStart 0
            /TrimEnd 2
            /MaxBand 4
            /Compressed 7
            /DeviceName (TIFF)
            /DeviceSpecifier [0 0 0 0 0 0 0 0]
            /XResolution 72
            /YResolution 72
            /PrintQuality 0
            /ImageNegate false
            /MarginNegate false
            /Exposure 0
            /XNegEnhance 0
            /YNegEnhance 0
            /MediaSelect 1
            /MediaOffset 0
            /MediaWidth 612
            /FFFF 10000
            /LeftMargin 0
            /RightMargin 0
            /TopMargin 0
            /BottomMargin 0
            /ImageWidth 612
            /ImageHeight 792
            /DataWidth 19584
            /CutAfterPage false
            /PrePageFeed 0
            /PostPageFeed 0
            /NoCopies 1
            /CtCopies 1
            /QueueType true
            /JobNumber 4
            /PageNumber 1
            /JobName (1. EMBEDDED.P65)
            /Locked false
            /MediaCenterPageWidth false
            /ColorType 0
            /ColorBits [8 8 8 8]
            /ColorValues [1 2 3 4]
            /ColorName (Composite)
            /TrimThePage false
            /XResFrac 0.0
            /YResFrac 0.0
            /RunLength false
            /ScreenDataCount 0
            /PluginDecompression -1
            /InsertSheet false
            /PaintNo 1
            /MediaCenterPageLength false
            /MediaHeight 792
            /RleScreenControl ()
            /RleScreenGenNum 0
            /Accelerator ()
            /CollateCopies false
            /RunOverlap true
            /OutputAttributes 0
            /NumSeparations 1
            /NumChannels 4
            /InterleavingStyle 2
            /RasterDepth 8
            /RasterFormat 3
            /ColorantFamily (DeviceCMYK)
            /DeviceType (TIFF)
            /Plugin (tiff.i32)
            /DeviceAddress ()
            /OutputQuality ()
            /JobNameUTF8 (1. EMBEDDED.P65)
            /MediaSize ()
            /NumGroupColorants 0
            /RleScreens []
            /OutputDeviceParameters
            <<
              /TiffRealPageNum 1
              /TiffTag270Value (Tag270-undef)
              /TiffTag270Type 0
              /TiffProxyTag false
              /TiffResetCounter false
              /TiffFilenameTemplate (TIFF<2unique>.TIF)
              /TiffFilenameGeneration (Conventional)
              /TiffUniqueFilenames true
              /TiffUse8Dot3 false
              /TiffKeepJobname false
              /TiffJobnameprefix false
              /TiffProcessWindow false
              /TiffProcessEnable false
              /TiffProcessCommand ()
              /TiffPadTo32Bit false
              /TiffAntiAlias (None)
              /TiffCompress (None)
              /TiffByteswap (IBM PC)
              /TiffBitflip false
              /TiffJobname false
              /TiffResolution false
              /TiffFormat (Multiple strips)
              /TiffSuffix (TIF)
              /TiffStem (TIFF)
              /TiffFolder (C:\\Documents and Settings\\duncanm\\Desktop\\HarlequinRIP\\SW\\)
              /TiffColorGen (None)
            >>
            /Colorants [
              <<
                /Channel 0
                /ColorantName (Cyan)
                /sRGBOriginal [0.0 1.0 1.0 ]
                /sRGBEquivalent [0.0 1.0 1.0]
                /SpecialHandling 0
                /CMYKEquivalent [1.0 0.0 0.0 0.0 ]
                /NeutralDensity 0.54000002
              >>
              <<
                /Channel 1
                /ColorantName (Magenta)
                /sRGBOriginal [1.0 0.0 1.0 ]
                /sRGBEquivalent [1.0 0.0 1.0]
                /SpecialHandling 0
                /CMYKEquivalent [0.0 1.0 0.0 0.0]
                /NeutralDensity 0.64999998
              >>
              <<
                /Channel 2
                /ColorantName (Yellow)
                /sRGBOriginal [ 1.0 1.0 0.0]
                /sRGBEquivalent [ 1.0 1.0 0.0 ]
                /SpecialHandling 0
                /CMYKEquivalent [0.0 0.0 1.0 0.0]
                /NeutralDensity 0.12
              >>
              <<
                /Channel 3
                /ColorantName (Black)
                /sRGBOriginal [0.0 0.0 0.0]
                /sRGBEquivalent [0.0 0.0 0.0]
                /SpecialHandling 0
                /CMYKEquivalent [0.0 0.0 0.0 1.0]
                /NeutralDensity 1.72
              >>
            ]
            /PaperType [
              (Any)
            ]
            /GroupColorants [
            ]
            >>
            %%PGBEndHeader: *** DO NOT ALTER THIS COMMENT (OR ANYTHING BEYOND IT) ***
            pgbimage

Notes on the example header:

The line starting %%PGBEndHeader: *** DO NOT ALTER is a backstop marker for the end of the header. It appears on one line in the header, but overflows its line length in the listing given here.
The apparently blank line before %%PGBEndHeader is filled with space characters. This white space allows for changes to the header to be made by writing to disk only the header, without the potentially large binary data. For example, the user can alter details that appear in the header using the Info dialog box, with any change in the text of the header being balanced by the addition or removal of white space.
The header has been lightly edited to shorten the listing in this document no values have been changed but the arrays have been reduced from multi-line entries each containing one value to one line holding all the values.

After the pgbimage line, there is binary data. This contains in sequence:

A band sizes table.
A band offset table.
The compressed bands themselves, in formats coded using a proprietary algorithm.