Actual orientation of image data. 0x0114 ∙ 276
IG_ISIS_TAG_DATAORIENTATION indicates or specifies the orientation when getting data from certain scanner drivers. If IG_ISIS_TAG_DATAORIENTATION is implemented in the scanner driver, then the scanner has the capability of internally rotating the image and the driver can be queried to determine whether or not the scanner is rotating the image.
IG_ISIS_TAG_TYPE_SHORT
IG_ISIS_TAG_DATAORIENTATION can be set to any one of the following values:
| 1 | IG_ISIS_ORIENTATION_PORT | The image data is in portrait orientation. |
| 2 | IG_ISIS_ORIENTATION_LAND | The image data is in landscape orientation. |
| 3 | IG_ISIS_ORIENTATION_180 | The image data is in upside-down portrait orientation. |
| 4 | IG_ISIS_ORIENTATION_270 | The image data is in upside-down landscape orientation. |
| 5 | IG_ISIS_ORIENTATION_PORTM | The image data is in portrait mirrored orientation. |
| 6 | IG_ISIS_ORIENTATION_LANDM | The image data is in landscape mirrored orientation. |
| 7 | IG_ISIS_ORIENTATION_180M | In ISIS, the image data is in upside down portrait, mirrored orientation. |
| 8 | IG_ISIS_ORIENTATION_270M | The image data is in upside down landscape, mirrored orientation. |
In ISIS, check for the existence of IG_ISIS_TAG_DATAORIENTATION in the currently-selected scanner driver. If this tag exists, check its choices to determine the rotation the scanner is capable of delivering. It you are scanning a portrait, letter-sized page sideways ("Scan and Rotate") to achieve better throughput, AND the scanner implements IG_ISIS_TAG_DATAORIENTATION, AND IG_ISIS_TAG_DATAORIENTATION is IG_ISIS_TAG_DATAORIENTATION_PORT, then the scanner is rotating the data for you, and you should not rotate it. On the other hand, if IG_ISIS_TAG_DATAORIENTATION is not implemented OR if IG_ISIS_TAG_DATAORIENTATION is set to IG_ISIS_TAG_DATAORIENTATION_LAND, then the scanner is not rotating the data for you and you should rotate it.