Reply To: 8-Bit image, memory transfer, algorithm problem

[mcohen]

Billie

I have a couple of questions. In calling the “DG_IMAGE, DAT_IMAGEMEMXFER, MSG_GET” tripplet, while I managed to get valid data, am having problems putting it together. The “TW_IMAGEMEMXFER” structure returns a value of “278” for compression. Beats me..! I don’t believe that value corresponds to any of the values from Twain:

TWCP_NONE = 0

TWCP_PACKBITS = 1

TWCP_GROUP31D = 2

TWCP_GROUP31DEOL = 3

TWCP_GROUP32D = 4

TWCP_GROUP4 = 5

TWCP_JPEG = 6

TWCP_LZW = 7

TWCP_JBIG = 8

TWCP_PNG = 9

TWCP_RLE4 = 10

TWCP_RLE8 = 11

TWCP_BITFIELDS = 12

Is it wise to retrieve the image in compressed format? Wouldn’t that complicate the process of compiling the Tiles/Strips into meaningful bitmaps?

Do you happen to have an example of how to request accepted compression values from the source using capability negotiation?