Logical order of bits within a byte. 0x010A ∙ 266

IG_ISIS_TAG_FILLORDER allows an application to specify or determine the order in which bits are stored in a byte.

Type:

IG_ISIS_TAG_TYPE_SHORT

Drivers:

All scanner drivers.

Values:

The only legal values for IG_ISIS_TAG_FILLORDER are:

1	IG_ISIS_FILLORDER_MSBLEFT	Pixels are arranged within a byte such that pixels with lower column values are stored in the higher-order bits of the byte. The first bit of the first byte corresponds to the first pixel on an uncompressed binary page.
2	IG_ISIS_FILLORDER_MSBRIGHT	Pixels are arranged within a byte such that pixels with lower column values are stored in the lower order bits of the byte. The last bit of the first byte corresponds to the first pixel on an uncompressed binary page.

Tag Dependencies and Dependent Tags:

IG_ISIS_TAG_FILLORDER applies only to binary images; therefore it has the following dependencies:

IG_ISIS_TAG_FILETYPE ∙ IG_ISIS_TAG_SAMPLESPERPIXEL ∙ IG_ISIS_TAG_BITSPERSAMPLE ∙ IG_ISIS_TAG_PHOTOMETRICINTERPRETATION ∙ IG_ISIS_TAG_FILLORDER

Remarks:

Used only for binary images, IG_ISIS_TAG_FILLORDER lets you indicate the order of pixels in the image data's bytes. The default value is MSB_LEFT, and this value should be used except in unusual circumstances.

Strictly speaking, this tag is optional; however, certain applications require this tag to be defined or they will not load the driver. Therefore, all ISIS drivers from Pixel create this tag.