TIFF Rule Test Operations
Table 1 describes the TIFF test operations
that Image
Compliance performs.
| Type | Name | Value | Description |
|---|---|---|---|
| Image | TIFF Header Required | Y, N | Verifies that the TIFF data starts with a TIFF header. When set to Y, the header must be present for the test to pass. When set to N, TIFF validation reports missing headers with no failures or other test results. |
| Image | Byte Order-Little | None | Verifies that the TIFF data byte order is little endian |
| Image | Byte Order-Big | None | Verifies that the TIFF data byte order is big endian |
| Image | IFD Valid | None | Verifies the TIFF image file directory (IFD) structure. The image file directory and its referenced data must be in the TIFF data. Image Compliance always performs this test. |
| Image | Tag Order Ascending | None | Verifies that the TIFF fields appear in ascending tag order. All fields in the first image file directory, including fields not specified in the rules, are tested. This test fails if two fields have the same tag number. |
| Image | Single Page | None | Verifies that the TIFF data contains a single image or page (single image file directory) |
| Image | Pointers Valid | None | Verifies that the TIFF header and the first image file directory (IFD) do not reference TIFF data from more than one place |
| Image | Decompress G4 Only | None | Validates the G4 compressed data. It parses the compressed bit stream in the image data and passes when the data complies with the ITU-T recommendation T.6 base coding scheme. The scheme defines the coding used for G4 facsimile. Image Compliance does not consider extensions such as uncompressed mode or valid. |
| Image | Decompress Len G4 Only | None | Verifies that the image length specified in the TIFF header matches the number of scan lines present in the G4 data. It parses the compressed bit stream in the image data and passes when the length in the header matches the number of G4 compressed scan lines. |
| Image | EOFB G4 Only | None | Verifies that the G4 compressed bilevel images have an end-of-facsimile block (EOFB) bit sequence |
| Image | Extra Pad G4 Only | n | Verifies the maximum number of full padding bytes the G4 compressed bilevel images can have after the EOFB bit sequence. Image Compliance allows 0 to 16. |
| Field | Mandatory | None | Defines if a TIFF field is required. If the field is optional, omit this test. This is the only field test that produces output when a TIFF field is absent. |
| Field | Equal (Value) | v1, v2, v3 (Refer to note 1) | Verifies that the field value equals one of a list of specified numbers |
| Field | Equal (Tag Ref) | n (Refer to note 2) | Verifies that the field value equals the value of another TIFF field |
| Field | Not Equal (Value) | v1, v2, v3 (Refer to note 1) | Verifies that the field value does not equal one of a specified list of numbers |
| Field | Not Equal (Tag Ref) | n (Refer to note 2) | Verifies that the field value does not equal the value of another TIFF field |
| Field | IFD Entry Field Type | v1, v2, v3 (Refer to note 1) | Verifies the TIFF field type equals one of a list of specified numbers. The field type number represents the data type of the field. The TIFF field type values are from the TIFF 6.0 standard. |
| Field | IFD Entry Field Count | v1, v2, v3 (Refer to note 1) | Verifies the TIFF field count equals one of a list of specified numbers. The field count is the number of values in the field |
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Note:
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