Re: Digital IR

[Andrew Davidhazy <ANDPPH@xxxxxxxxxxxxxxxxxx>]

> So on this image...
> http://www.rit.edu/~andpph/a-scanner/handy-scan-vis-ir-pair-1a.jpg

> The top half is regular b&w  and the second is infra red created with a
> manipulated b&w digital camera with red filter?   Or am I lost?   And how did
> you do that bottom half again?  :-)

Right. But the bottom one is not made with a "manipulated B&W camera" but with
a camera "I made" by taking parts out of a hand-operated (you roll the scanner
over a photo or image or text) scanner and installing the CCD line array into a
SLR camera body. The only reason the image is in B&W is that I was scanning in
256 shades of grey since I would be comparing the picture to an an _infrared_
record which, because infrared does not have a "color" would end up in black
and white. So I used grey tones for both the visible and the IR record. I was
suspecting that the file sizes and such when scanning in color would be pretty
large also. Right now a single scan at 400 dpi turns out to be about a 10Mb
file and my computer takes a long time to deal with it.

Anyway, to make a picture you essentially scan a landscape or a scene with the
array installed in the camera. For the picture you are referring to here the
rotation of the camera was accomplished by turning it on the tripod by hand.
Later I built a motorized "turner" that I attached to my tripod so the scanning
action is more predictable and even. 

BTW, there is an article at: www.rit.edu/~andpph/text-demo-scanner-cam.html     
where the general approach is described. At the time I wrote that artcile I had 
cannibalized a Kodak Snapshot scanner ... which got the ball rolling for me but
which has some "idiosynchrosies" that, while interesting, interfere with smooth
scanning.                                                                      
 

Andy  o o  0 0 o . o  Davidhazy, Imaging and Photo Tech
       \/\/\/\/\/\/          http://www.rit.edu/~andpph
________|        |_____________________________________


*
****
*******
******************************************************
*  To remove yourself from this list, send:          *
*         UNSUBSCRIBE INFRARED                       *
*       to                                           *
*         MAJORDOMO@xxxxx                            *
*----------------------------------------------------*
*   For the IR-FAQ, IR-Gallery and heaps of links:   *
*  http://www.a1.nl/phomepag/markerink/mainpage.htm  *
******************************************************