TIFF Tag CleanFaxData
| IFD | Image |
|---|---|
| Code | 327 (hex 0x0147) |
| Name | CleanFaxData |
| LibTiff name | TIFFTAG_CLEANFAXDATA |
| Type | SHORT |
| Count | 1 |
| Default | None |
Description
Used in the TIFF-F standard, indicates if 'bad' lines encountered during reception are stored in the data, or if 'bad' lines have been replaced by the receiver.
The TIFF-F standard defines these values:
0 = No 'bad' lines
1 = 'bad' lines exist, but were regenerated by the receiver
2 = 'bad' lines exist, but have not been regenerated.
LibTiff defines these values:
CLEANFAXDATA_CLEAN = 0;
CLEANFAXDATA_REGENERATED = 1;
CLEANFAXDATA_UNCLEAN = 2;
NOTE: Many facsimile devices do not actually output bad lines. Instead, the previous good line is repeated in place of a bad line. Although this substitution, known as line regeneration, results in a visual improvement to the image, the data is nevertheless corrupted. The CleanFaxData field describes the error content of the data. That is, when the BadFaxLines and ImageLength fields indicate that the facsimile device encountered lines with an incorrect number of pixels during reception, the CleanFaxData field indicates whether these bad lines are actually still in the data or if the receiving facsimile device replaced them with regenerated lines.