"

 COPYRIGHT (c) 1991 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

ImageReader subclass:#TIFFReader

	instanceVariableNames:'planarConfiguration subFileType stripOffsets rowsPerStrip

		fillOrder compression group3options predictor stripByteCounts

		currentOffset stripOffsetsPos stripByteCountsPos bitsPerSamplePos

	classVariableNames:''

	poolDictionaries:''

	category:'Graphics-Images-Support'

!

!TIFFReader class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1991 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    This class knows how to read TIFF files and how to

    write uncompressed TIFF files.

    Only single image files are supported.

    Not all formats are implemented, and of those that are, not all are tested.

    It should read with most rgb, mono and 2-plane greyscale

    images, since this is what I have as test material on the NeXT.

    It supports reading of uncompressed, LZW and G3 compressed 

    images; JPEG and packbits are currently not implemented.

    Only writing of uncompressed images is currently implemented.

    It should write (at least) mono, 8-bit palette and 24 bit rgb formats.

    More formats will come ...

    TODO: since I dont want to spend all of my life adding more formats here and

    reinventing the wheel, this code should be changed to use the tiff library.

    That would give us most formats and also writing capabilities for free.

    [author:]

        Claus Gittinger

    [See also:]

        Image Form Icon

        BlitImageReader FaceReader GIFReader JPEGReader PBMReader PCXReader 

        ST80FormReader SunRasterReader TargaReader WindowsIconReader 

        XBMReader XPMReader XWDReader 

"

! !

!TIFFReader class methodsFor:'initialization'!

initialize

    "install myself in the Image classes fileFormat table

     for the `.tiff', `.tif' and '.TIF' extensions."

    Image fileFormats at:'.tiff' put:self.

    Image fileFormats at:'.tif'  put:self.

    Image fileFormats at:'.TIF'  put:self.

! !

!TIFFReader class methodsFor:'testing'!

canRepresent:anImage

    "return true, if anImage can be represented in my file format.

     Any image is supported."

    ^ true

!

isValidImageFile:aFileName

    "return true, if aFileName contains a GIF image"

    |inStream char1 char2 version|

    inStream := self streamReadingFile:aFileName.

    inStream isNil ifTrue:[^ false].

    char1 := inStream next.

    char2 := inStream next.

    ((char1 ~~ char2) or:[(char1 ~~ $I) and:[char1 ~~ $M]]) ifTrue:[

	inStream close.

	^ false

    ].

    inStream binary.

    version := inStream nextShortMSB:(char1 == $M).

    inStream close.

    (version ~~ 42) ifTrue:[^ false].

    ^ true

! !

!TIFFReader methodsFor:'private'!

decodeTiffTag:tagType numberType:numberType length:length

    |offset value valueArray 

     val scaleFactor rV gV bV

     n  "{ Class: SmallInteger }"

     i2 "{ Class: SmallInteger }"

     i3 "{ Class: SmallInteger }" |

    (numberType == 3) ifTrue:[

        "short"

        valueArray := self readShorts:length.

        value := valueArray at:1

    ] ifFalse:[

        (numberType == 4) ifTrue:[

            "integer"

            valueArray := self readLongs:length.

            value := valueArray at:1

        ] ifFalse:[

            (numberType == 2) ifTrue:[

                "character"

                value := self readChars:length

            ] ifFalse:[

                (numberType == 5) ifTrue:[

                    "fraction"

                    valueArray := self readFracts:length.

                    value := valueArray at:1

                ] ifFalse:[

                    offset := (inStream nextLongMSB:(byteOrder ~~ #lsb))

                ]

            ]

        ]

    ].

    (tagType == 254) ifTrue:[

        "NewSubfileType"

        "newSubFileType := value."

        ^ self

    ].

    (tagType == 255) ifTrue:[

        "SubfileType"

        subFileType := value.

        ^ self

    ].

    (tagType == 256) ifTrue:[

        "ImageWidth"

        width := value.

        ^ self

    ].

    (tagType == 257) ifTrue:[

        "ImageHeight"

        height := value.

        ^ self

    ].

    (tagType == 258) ifTrue:[

        "bitspersample"

         bitsPerSample := valueArray.

        ^ self

    ].

    (tagType == 259) ifTrue:[

        "compression"

        compression := value.

        ^ self

    ].

    (tagType == 262) ifTrue:[

        "photometric"

        (value == 0) ifTrue:[

          photometric := #whiteIs0

        ] ifFalse:[

          (value == 1) ifTrue:[

            photometric := #blackIs0

          ] ifFalse:[

            (value == 2) ifTrue:[

              photometric := #rgb

            ] ifFalse:[

              (value == 3) ifTrue:[

                photometric := #palette

              ] ifFalse:[

                (value == 4) ifTrue:[

                  photometric := #transparency

                ] ifFalse:[

                  (value == 5) ifTrue:[

                    photometric := #separated  "/ color separations

                  ] ifFalse:[

                    (value == 6) ifTrue:[

                      photometric := #ycbr    "/ CCIR 601

                    ] ifFalse:[

                      (value == 8) ifTrue:[

                        photometric := #cielab  "/ 1976 CIE L*a*b*

                      ] ifFalse:[

                        photometric := nil

                      ]

                    ]

                  ]

                ]

              ]

            ]

          ]

        ].

        ^ self

    ].

    (tagType == 263) ifTrue:[

        "Treshholding"

        "threshholding := value."

        ^ self

    ].

    (tagType == 264) ifTrue:[

        "CellWidth"

        "cellWidth:= value."

        ^ self

    ].

    (tagType == 265) ifTrue:[

        "CellLength"

        "cellLength:= value."

        ^ self

    ].

    (tagType == 266) ifTrue:[

        "fillOrder"

        (value == 1) ifTrue:[

          fillOrder := #msb

        ] ifFalse:[

          (value == 2) ifTrue:[

            fillOrder := #lsb

          ] ifFalse:[

            fillOrder := nil

          ]

        ].

        ^ self

    ].

    (tagType == 269) ifTrue:[

        "documentName - info only"

        ^ self

    ].

    (tagType == 270) ifTrue:[

        "imageDescription - info only"

        ^ self

    ].

    (tagType == 271) ifTrue:[

        "make - info only"

        ^ self

    ].

    (tagType == 272) ifTrue:[

        "model - info only"

        ^ self

    ].

    (tagType == 273) ifTrue:[

        "stripoffsets"

        stripOffsets := valueArray.

        ^ self

    ].

    (tagType == 274) ifTrue:[

        "Orientation"

        ^ self

    ].

    (tagType == 277) ifTrue:[

        "samplesPerPixel"

        samplesPerPixel := value.

        ^ self

    ].

    (tagType == 278) ifTrue:[

        "rowsperstrip"

        rowsPerStrip := value.

        ^ self

    ].

    (tagType == 279) ifTrue:[

        "stripbytecount"

        stripByteCounts := valueArray.

        ^ self

    ].

    (tagType == 280) ifTrue:[

        "MinSampleValue"

        "minSampleValue:= value."

        ^ self

    ].

    (tagType == 281) ifTrue:[

        "MaxSampleValue"

        "maxSampleValue:= value."

        ^ self

    ].

    (tagType == 282) ifTrue:[

        "xResolution"

        ^ self

    ].

    (tagType == 283) ifTrue:[

        "yResolution"

        ^ self

    ].

    (tagType == 284) ifTrue:[

        "planarconfig"

        (value == 1) ifTrue:[

          planarConfiguration := 1

        ] ifFalse:[

          (value == 2) ifTrue:[

            planarConfiguration := 2

          ] ifFalse:[

            planarConfiguration := nil

          ]

        ].

        ^ self

    ].

    (tagType == 285) ifTrue:[

        "pageName"

        ^ self

    ].

    (tagType == 286) ifTrue:[

        "xPosition"

        ^ self

    ].

    (tagType == 287) ifTrue:[

        "yPosition"

        ^ self

    ].

    (tagType == 288) ifTrue:[

        "freeOffsets"

        ^ self

    ].

    (tagType == 289) ifTrue:[

        "freeByteCounts"

        ^ self

    ].

    (tagType == 290) ifTrue:[

        "grayResponceUnit"

        ^ self

    ].

    (tagType == 291) ifTrue:[

        "grayResponceCurve"

        ^ self

    ].

    (tagType == 292) ifTrue:[

        "group3options"

        group3options := value.

        ^ self

    ].

    (tagType == 293) ifTrue:[

        "group4options"

        "group4options := value."

        ^ self

    ].

    (tagType == 296) ifTrue:[

        "resolutionunit"

        "resolutionUnit := value."

        ^ self

    ].

    (tagType == 297) ifTrue:[

        "pageNumber"

        "pageNumber := value."