Below are full explanations of the various predefined tags contained in the Document Imaging SDK:
ID: 254 (hFE)
Type: LONGTYPE
Count: 1
Default: NORMALVERSION
This tag is a flag indicating the kind of the image being used. This tag was introduced to replace the old SUBFILETYPE tag. Unused bits are expected to be set to zero. Currently defined values are given below:
Bit 0 - set to 1 if the image is a reduced resolution version of another image in the same TIFF file
Bit 1 - set to 1 if the image is a page of a multi-page image
Bit 2 - set to 1 if the image is a transparency mask for another image in the same TIFF file
Use the predefined REDUCED VERSION, APAGEOFAMULTIPAGE and TRANSPARENCYMASK macros. NORMALVERSION macro is simply zero.
ID: 255 (hFF)
Type: SHORTTYPE
Count: 1
Default: OLDFULLVER
This value indicates the image type. The meaningful values are as follows:
1 Full resolution image (OLDFULLVER)
2 Reduced resolution version (OLDREDUCEDVER)
3 Single page of a multi-page image (OLDAPAGE)
This tag is no longer recommended. Use NEWSUBFILETYPE instead.
ID: 256 (h100)
Type: SHORTTYPE or LONGTYPE
Count: 1
This tag indicates the width of an image in pixels. Also see IMAGELENGTH.
ID: 257 (h101)
Type: SHORTTYPE or LONGTYPE
Count: 1
This tag value indicates the height of an image in pixels. Also see IMAGEWIDTH.
ID: 258 (h102)
Type: SHORTTYPE
Count: SamplesPerPixel
Default: 1
This value indicates the number of bits representing a pixel in a color plane. The number of color planes is defined in the SAMPLESPERPIXEL tag. The most frequent values for the two tags are given below:
|
Image Type |
SAMPLESPERPIXEL |
BITSPERPIXEL |
Number of Colors |
|
Monochrome |
1 |
1 |
2 |
|
Palette color |
1 |
4 |
16 |
|
Palette color |
1 |
8 |
256 |
|
RGB |
3 |
8 |
|
ID: 259 (h103)
Type: SHORTTYPE
Count: 1
Default: NOCOMPRESSION
The compression type of the image. Predefined values are shown below:
|
Value |
Macro Name |
Description |
|
1 |
No compression. Each row begins on a byte boundary. |
|
|
2 |
CCITT Group 3 |
|
|
3 |
CCITT Group 3 coding. See the GROUP3OPTIONS tag for more information. |
|
|
4 |
CCITT Group4 coding. See the GROUP4OPTIONS tag for more information. |
|
|
5 |
LZW compression. See the PREDICTOR tag for more information. |
|
|
6 |
JPEG baseline or losses compression. |
|
|
32773 |
PackBits compression, a simple byte-oriented run-length coding scheme. |
The CCITT coding scheme works only on bi-level images.
Name: PHOTOMETRICINTERPRETATION
ID: 262 (h106)
Type: SHORTTYPE
Count: 1
|
Value |
Macro Name |
Description |
|
0 |
Bi-level and grayscale images. Zero means white, 2BitsPerSample, 1 means black. |
|
|
1 |
Bi-level and grayscale images. TwoBitsPerSample, “1” means white, “0” means black. |
|
|
2 |
RGB image. See PLANARCONFIGURATION tag for more information. |
|
|
3 |
Palette color image. See COLORMAP tag for the color map. |
|
|
4 |
Bi-level transparency mask. ??? |
ID: 266 (h10A)
Type: SHORTTYPE
Count: 1
Default: NORM_BIT_ORDER
This tag defines the order of image data values within a byte. NORM_BIT_ORDER means that the most significant bits of the byte comes first. REV_BIT_ORDER assumes reverse bit order in the data values. Use of this tag is no longer recommended. In any case, the default value, NORM_BIT_ORDER, must be used.
ID: 269 (h10D)
Type: ASCIITYPE
Count: Length of string including terminating zero
This tag contains the name of the document where the image originated from.
ID: 270 (h10E)
Type: ASCIITYPE
Count: Length of string including terminating zero
The tag contains a title or description of the image.
ID: 273 (h111)
Type: SHORTTYPE or LONGTYPE
Count: Strips per image if PlanarConfiguration is equal to 1
SamplesPerPixel * Strips per image if PlanarConfiguration is equal to 2
The offsets of the strips counting from the beginning of the file. See also STRIPBYTECOUNTS and ROWSPERSTRIP tags.
ID: 277 (h115)
Type: SHORTTYPE
Count: 1
Default: 1
This tag represents the number of samples per pixel. The value normally is “1” for monochrome, grayscale and palette color images. For RGB images, the value is “3”.
ID: 278 (h116)
Type: SHORTTYPE or LONGTYPE
Count: 1
Default: The entire image is one strip
This tag contains the number of rows in a strip. The image rows are organized into strips to help applications accessing compressed subimages. The offset and length of each strip is stored in STRIPOFFSETS and STRIPBYTECOUNTS tags, respectively. The last strip of the image may contain fewer rows than the others. Applications sometimes use special values (232-1, or 0) to indicate that the entire image is one strip.
ID: 279 (h117)
Type: SHORTTYPE or LONGTYPE
Count: Strips per image if PlanarConfiguration is equal to 1
SamplesPerPixel * Strips per image if PlanarConfiguration is equal to 2
This tag contains the number of code bytes in each strip. Also see STRIPOFFSETS and ROWSPERSTRIP. It is strongly recommended that this tag be defined when creating a TIFF file. The tag’s existence greatly simplifies decoding.
ID(s): 282 (h11A) and 283 (h11B), respectively
Type: RATIONALTYPE
Count: 1
These tags define the number of pixels per ResolutionUnit in the X and Y directions, respectively. Also see RESOLUTIONUNIT.
ID: 284 (h11C)
Type: SHORTTYPE
Count: 1
Default: 1
This tag is employed only if the value of SamplesPerPixel equals “3” (e.g., in the case of RGB images). If PlanarConfiguration equals “1”, the sample values of each pixel are stored contiguously (RGBRGBRGBRGB...). If PlanarConfiguration equals “2”, the Red, Green and Blue strips are stored contiguously. (Note: Document Imaging SDK can only handle images with planar configuration defined as “1”.)
ID: 283 (h11D)
Type: ASCIITYPE
Count: Length of string including terminating zero
The tag stores the name of the page the image was scanned from.
ID: 290 (h122)
Type: SHORTTYPE
Count: 1
Default: NOCOMPRESSION
This tag modifies the interpretation of GRAYRESPONSECURVE. The GrayResponseCurve values must be multiplied by 10GrayResponseUnit.
ID: 291 (h123)
Type: SHORTTYPE
Count: 2BitsPerSample
This tag defines a lookup table, mapping values from 0 to 2BitsPerSample-1 into real density values. If both GRAYRESPONSECURVE and PHOTOMETRICINTER-PRETATIONS tags exist, GrayResponseCurve overrides the Photometric Interpretation value. Also see GRAYRESPONSEUNIT.
ID: 292 (h124)
Type: LONGTYPE
Count: 1
Default: 0L
This tag supplies further information to the CCITT Group 3 compression algorithm. The value is a bit field. The meanings of the bits are as follows:
Bit 0 0 for one-dimensional, 1 for two-dimensional
Bit 1 is 1 if uncompressed mode is used
Bit 2 is 1 if fill bits are used before EOL codes
Use the predefined CCITT_ID, CCITT_2D, CCITT_UNCOMP and CCITT_FILLBITS macros. Also, see the COMPRESSION tag description.
ID: 293 (h125)
Type: LONGTYPE
Count: 1
Default: 0L
This tag provides further information to the CCITT Group 4 compression algorithm. The value is a bit field. The meanings of the bits are listed below:
Bit 0 unused
Bit 1 is 1 if uncompressed mode is used
Use the predefined CCITT_UNCOMP macro. Also see the description for the COMPRESSION tag.
ID: 296 (h128)
Type: SHORTTYPE
Count: 1
Default: RES_IN_INCH
This tag supplies the unit measurement of XResolution and YResolution values.
Predefined values are:
1 No absolute unit
2 Inch
3 Centimeter
Use the predefined RES_IN_NODEF, RES_IN_INCH and RES_IN_CM macros. Also see the definitions for XRESOLUTION and YRESOLUTION tags.
ID: 297 (h129)
Type: SHORTTYPE
Count: 2
This tag is used with multiple page (facsimile) documents. The first value is the page number, the second is the total number of pages in the document. The first page is zero.
ID: 301 (h12D)
Type: SHORTTYPE
Count: 1
Default: 3 * 2BitsPerSample
The purpose of the color response curves is to refine the content of RGB color images. The tag defines three color response curves for the Red, Green and Blue colors, respectively. Zero represents the minimum intensity, and 65535 represents the maximum intensity.
ID: 306 (h131)
Type: ASCIITYPE
Count: Length of string including terminating zero
This tag contains the name and release number of the software that created the image.
ID: 306 (h132)
Type: ASCIITYPE
Count: 20
This tag supplies the date and time when the image was created. The recommended format is “YYYY:MM:DD HH:MM:SS” with a space between date and time.
ID: 315 (h13B)
Type: ASCIITYPE
Count: Length of string including terminating zero
This tag contains the name of the person who created the image or copyright notice. It is a custom to put the copyright string just after the 8-byte header of the TIFF file.
ID: 317(h13D)
Type: SHORTTYPE
Count: 1
Default: LZW_NORMAL
This tag is used to provide further information if LZW compression is used. Possible values are explained below:
1 No prediction scheme was used
2 Horizontal differenting was used
Use the predefined LZW_NORMAL and LZW_HORIZDIFF macros.
ID: 320 (h140)
Type: SHORTTYPE
Count: 3 * 2BitsPerSample
This tag stores the Red, Green and Blue subcurves. The palette color pixel color values are used to index into the three subcurves producing an RGB value for that pixel value. The subcurves are stored sequentially, with the Red subcurve stored first. In each subcurve, zero represents the minimum intensity, 65535 represents the maximum intensity.
ID: 322(h142)
Type: SHORTTYPE or LONGTYPE
Count: 1
This tag specifies width of the tiles in pixels. Tile height must be a multiple of 16. The number of tiles in an image can be computed as below.
TilesPerImage = (ImageWidt+TileWidth-1)/TileWidth * (ImageLength+TileHeight-1)/TileLength
ID: 323(h143)
Type: SHORTTYPE or LONGTYPE
Count: 1
This tag specifies height of the tiles in pixels. Tile height must be a multiple of 16.
ID: 325(h145)
Type: SHORTTYPE or LONGTYPE
Count: TilesPerImage ( if PLANARCONFIGURATION equal to 1)
TilesPerImage*SamplesPerPixel( if PLANARCONFIGURATION equal to 2)
This tag points to an array of numbers, which specify the offset of compressed data for each tile. The offsets are ordered by planes and left-to right and top-to-bottom The offsets are specified from the beginning of the TIFF file.
ID: 324(h144)
Type: LONGTYPE
Count: TilesPerImage ( if PLANARCONFIGURATION equal to 1)
TilesPerImage*SamplesPerPixel( if PLANARCONFIGURATION equal to 2)
This tag points to an array of numbers, which specify the number of compressed bytes in each tile.
ID: 512(h200)
Type: SHORTTYPE
Count: 1
Default: 1
This tag specifies the JPEG process used to compress and decompress image data. Possible values are explained below:
1 Baseline sequential algorithm
2 Losses algorithm with Huffman coding
ID: 513(h201)
Type: LONGTYPE
Count: Length of interchange format bitstream.
This tag points the representation of compressed image data for exchange between application. This tag must point a Start of Image (SOI) marker code. If this tag is omitted or zero, then JPEG interchange format bitstream is not present.
Name: JPEGINTERCHANGEFORMATLENGTH
ID: 514(h202)
Type: LONGTYPE
Count: 1.
This tag indicates the size of the interchange format data in bytes.
ID: 515(h203)
Type: SHORTTYPE
Count: 1
This tag defines the size of fixed intervals the input image is divided into. Restart markers not need be present in a TIFF file. Strip an tile pointers shall always point to the beginning of a restart interval. The encoding and decoding of each interval is done independently of the other intervals.
ID: 517(h205)
Type: SHORTTYPE
Count: SamplesPerPixel
This tag points to an array of losses predictor values. This field is used when a losses JPEG process is defined (JPEGPROC tag). The available predictors are
|
Selection value |
Prediction |
|
1 |
a |
|
2 |
b |
|
3 |
c |
|
4 |
a+b+c |
|
5 |
a+(b-c)/2 |
|
6 |
b+(a-c)/2 |
|
7 |
(a+b)/2 |
where ‘a’ is the sample on the left, ‘b’ is the sample above and ‘c’ is on the left and above the sample to be coded.
ID: 518(h206)
Type: SHORTTYPE
Count: SamplesPerPixel
This tag points to an array of transform r-values. Prior to the coding the input value will be divided by 2**Pt if the value of Pt is non zero, where Pt is the transform value. This tag is used when a losses JPEG process is defined (JPEGPROC tag).
ID: 519(h207)
Type: LONGTYPE
Count: SamplesPerPixel
This tag points to an array of offsets of the quantization tables. A quantization value is set to a individual DCT. The size of a table is 64 in bytes. This tag is used when a DCT process is defined (JPEGPROC tag).
ID: 520(h208)
Type: LONGTYPE
Count: SamplesPerPixel
This tag points to an array of offsets of the DC or losses Huffman tables. A DC value is set to a individual DCT. The size of a table is 33 in bytes.
ID: 520(h208)
Type: LONGTYPE
Count: SamplesPerPixel
This tag point to an array of offset of theAC Huffman tables. An AC value is set to a individual DCT. The size of a table is 272 in bytes. This tag is used when a DCT process is defined (JPEGPROC tag).