In article <20011221152045.99878.qmail@web20708.mail.yahoo.com>, Michael Greer <mgreer316@yahoo.com> writes > >I've never seen or driven a scanner with a hardware exposure control. I am pretty sure that all of the Nikon range do, they certainly all used to do this, but I can't be certain about the more recent units such as the LS40/4000/8000 etc. >What does >it do anyway? Does it vary the intensity of the light source? No - it varies the exposure time. >In the past, the scan process >was: >1) the scanner's hardware would capture the image in higher bits. >2) the software driver would process that image in higher bits. >3) the software driver would return the image to the host in 8 bits. > >In step 2, the computer is being used to process the image. Whether it's done >in the scan driver software or the image editor is irrelevant. The computer >still needs to horse power to handle it. > Eh??? Either: a) you haven't explained what you mean particularly clearly, b) you've got this backwards or, c) scanner manufacturers have secretly developed a matter transporter and are temporarily beaming the CPU down those SCSI wires to the scanner to implement avail themselves of that "horse power" in the scanner. My bet's on (a), but I would love to be convinced that its (c). :-) Either the data is processed in the scanner's firmware (and reduced to 8-bits by that) or it is transferred to the computer in high bit level and processed by the CPU (requiring the appropriate "horse power" to do so) - you can't have it both ways! If it is returned to the computer in high bit, then it is available to the application in high bit (unless the driver has been deliberately crippled, in which case Ed Hamrick's application will probably overcome that restriction, ensuring that a competitive upgrade will be available from the vendor eventually. If it is only returned in 8-bit then it MUST be processed in the scanner's firmware without any significant load on the host computer. Scanners already contain an ALU for calibration correction anyway - reduction of the data to 8-bit range is simply a modification of the correction data fed to that ALU for each pixel in the CCD. There is a marginal increase in load on the computer in calculating each of the pixel correction coefficients for the ALU - one entire pixel line's worth of calculations. -- Kennedy Yes, Socrates himself is particularly missed; A lovely little thinker, but a bugger when he's pissed. Python Philosophers - Turn off HTML mail features. Keep quoted material short. Use accurate subject lines. http://www.leben.com/lists for list instructions.