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pdfblur (1)
NAME
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pdfblur - generate views for depth-of-field blurring |
SYNOPSIS
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pdfblur aperture distance nsamp viewfile |
DESCRIPTION
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Pdfblur takes the given viewfile and computes
nsamp views based on a focus distance of
distance and an aperture diameter of aperture
(both in world coordinate units). When rendered and averaged
together, these views will result in a picture with the
specified depth of field. Either pinterp(1) or
rpict(1) may be called to do the actual work. (The
given viewfile must also be passed on the command
line to the chosen renderer, since pdfblur provides
supplemental view specifications only.) |
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For pinterp, feed the output of pdfblur to the
standard input of pinterp and apply the -B
option to blur views together. In most cases, a single
picture with z-buffer is all that is required to get a
satisfactory result, though the perfectionist may wish to
apply three pictures arranged in a triangle about the
aperature, or alternatively apply the -ff option
together with the -fr option of pinterp. (The
latter may actually work out to be faster, since rendering
three views takes three times as long as a single view, and
the -fr option will end up recomputing relatively few
pixels by comparison.) |
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To use pdfblur with rpict, apply the -S
option to indicate a rendering sequence, and set the
-o option with a formatted file name to save multiple
output pictures. When all the renderings are finished,
combine them with the pcomb(1) program, using
appropriate scalefactors to achieve an average. Note that
using rpict is MUCH more expensive than using
pinterp, and it is only recommended if the scene and
application absolutely demand it (e.g. there is prominent
refraction that must be modeled accurately). |
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For both pinterp and rpict, the computation
time will be proportional to the number of views from
pdfblur. We have found a nsamp setting
somewhere between 5 and 10 to be adequate for most images.
Relatively larger values are appropriate for larger
aperatures. |
EXAMPLES
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To use pinterp to simulate an aperture of 0.5 inches
on a lens focused at a distance of 57 inches: |
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rpict -vf myview -x 640 -y 480 -z orig.zbf scene.oct >
orig.pic
pdfblur 0.5 57 8 orig.pic | pinterp -B -vf orig.pic -x 640
-y 480 orig.pic orig.zbf > blurry.pic |
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To use rpict exclusively to do the same: |
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pdfblur .5 57 5 myview | rpict -S 1 -vf myview -x 640 -y 480
-o view%d.pic scene.oct
pcomb -s .2 view1.pic -s .2 view2.pic -s .2 view3.pic -s .2
view4.pic -s .2 view5.pic > blurry.pic |
AUTHOR
BUGS
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This program really only works with perspective
views. |
SEE ALSO
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