The purpose of this article is to detail the product functionality that determines which TIFF compression is used.
Document Conversion Activity
Introduced in TotalAgility 7.5, Document Conversion Profiles do not have an explicit compression setting and instead use compression determined by the Image Color Depth setting. When set to Black and White images will use Group 4 compression, which only supports black and white images. When set to either Color or Grayscale images will use LZW compression.
Scan And Image Processing Activity
When configuring a Scan/VRS Profile, setting the Color option to Black and White will result in images that use Group 4 compression. Choosing any other option enables the JPEG compression option, where Yes uses JPEG compression and No results in no compression.
Note that even though the setting is called "JPEG compression", when Color is set to Automatic, this is applicable to black and white images as well. When the setting is off, both color images and black and white images will be uncompressed. When the setting is on, color images will be JPEG compressed and black and white images will be Group 4 compressed.
There are no SDK functions that explicitly change the TIFF compression. Functions that produce a TIFF such as GetDocumentFile and GetDocumentAsFile require that the TIFF already exists as a result of import or conversion via a Document Conversion activity or an Image Processing activity. Thus the TIFFs from these functions retain the compression already in use.
When configuring an export connector to export TIFF images there may be additional compression options that depend on the specific implementation of that connector. The Text and Database Export Connectors provide the following options on the Advanced tab of the connector setup:
- TIFF with Group 4 compression
- TIFF with no compression
- TIFF with G31D compression
- TIFF with G32D compression
- TIFF with JPEG compression
- TIFF with LZW compression
JPEG in TIFF
Note that where JPEG compression is used, this refers to the Technical Note 2 update to the TIFF 6.0 standard (compression scheme 7, "New" JPEG in TIFF), not compression scheme 6 ("Old" JPEG in TIFF) which was made obsolete by the Technical Note 2 update. For context, Kofax Capture import and export sources use the legacy format as default and provides an option to change to the Technical Note 2 specification.
Level of Complexity