[JPEG Transfer] Check Box

When this check box is selected, scanned image data is always compressed to JPEG format within the scanner for output to the computer.

Scanned image data is output from the scanner as an uncompressed or JPEG transfer, depending on instructions from the ISIS/TWAIN driver or application program.

☞Uncompressed transfers output raw scanned image data, so when the image data is large, significant time may be required for transfer from the scanner to the computer.

☞JPEG transfer is good for color and grayscale images, as scanned image data is JPEG-compressed within the scanner before output.

This reduces the size of the image data for output, so transfer time from the scanner to the computer is shortened.

When JPEG Transfer is selected, image data from the scanner is always output as JPEG-compressed data.

☞When the uncompressed saving format is selected in the application program, JPEG-compressed image data is reconverted to uncompressed data before transfer to the application. Image quality is degraded slightly as a result.

☞This check box setting is ignored if the application program requests a JPEG transfer.

☞Of course application program requests depend on the specifications of the particular program.

Double Feed Detection

This function stops document transport when double feeding of document pages is detected, and provides selection of the detection method to suit the documents to be scanned. (See “Double Feed Detection Function,” on p. 54.)

[Detect by Length]

This method of double feed detection is good for batch scanning of same-size documents: the length of the first document page fed is taken as a standard, and when a subsequent document is detected to be 1.96" (50 mm) longer (or shorter) than the standard, a double feed is judged to have occurred, and document transport is stopped.

[Detect by Ultrasonic]

This method of double feed detection is good for batch scanning of different- size documents: the overlapping of documents transported in a batch is detected ultrasonically, and if the detected overlap is 1.96" (50 mm) or more, a double feed is judged to have occurred and document transport is stopped.

☞Both detection methods can be used at the same time.

☞If the documents overlap by less than 1.96" (50 mm), or if the documents cling (such as from static electricity,) ultrasonic detection of double feeds may be unreliable.

82Chapter 3