.TH "pfshdrcalibrate" 1
.SH NAME
pfshdrcalibrate \- Create an HDR image or calibrate a response curve
from a set of differently exposed images supplied in PFS stream.

.SH SYNOPSIS
.B pfshdrcalibrate
[--response <type>] [--calibration <type>]
[--gauss <val>]
[--response-file <filename.m>]
[--save-response <filename.m>]
[--multiplier <val>] [--bpp <val>]
[--luminance]
[--help] [--verbose]

.SH DESCRIPTION
Create an HDR image or calibrate a response curve from a set of
differently exposed images supplied in PFS stream.

When used with 8bit images, luminance in the output HDR image
corresponds to real world values in [cd/m^2] provided that hdrgen
script contained correct information on exposure time, aperture and
iso speed. Note that sometimes ISO speed indicated by camera does not
correspond to standard (ISO-100 is in fact ISO-125).

The accuracy of absolute calibration has not been thoroughly tested
with different camera models, however one can expect the relative
measurement error below 8%. Use pfsabsolute in case of systematic
error.

.SH OPTIONS
.TP
--response <type>, -r <type>

Allows to choose from predefined response curves. This can be used
either to apply this response or use it as an initialization for
automatic self-calibration. Predefined response curves are: "linear",
"gamma", "log". Default is "linear".

.TP
--calibration <type>, -c <type>

Type of automatic self-calibration method used for recovery of the
response curve. Accepted types include: "none", "robertson",
"debevec". (well, at this time only "robertson" works). Default is
"robertson". In case "none" is chosen, a predefined response will be
used, without self-calibration.

.TP
--gauss <val>, -g <val>

Sigma value for the Gaussian used as a weighting function. Applies to
Robertson02 algorithm. Default value: 16.0f

.TP
--response-file <filename.m>, -f <filename.m>

Use response curve saved in the matlab format file. Turns off
automatic self-calibration. Uses Robertson02 model to apply the
response curve.

.TP
--save-response <filename.m>, -s <filename.m>

Saves the response curve calculated during automatic self-calibration
stage in a matlab format file. Can be later reused for set of images
captured with given camera. Also works fine for plotting with gnuplot.

.TP
--multiplier <val>, -m <val>

Input multiplier value. Can be used to manipulate the range of source
exposures. Default value is 256 since LDR images are by default scaled
to 0..1.

.TP
--bpp <val>, -b <val>

Number of bits per pixel in input data from the camera. Default value
is 8.

.TP
--luminance, -Y

Recovery of response curve will be performed for luminance channel only.

.TP
--verbose

Print additional information during program execution.
.TP
--help

Print list of commandline options.

.SH EXAMPLES
.TP
pfsinhdrgen sample.hdrgen | pfshdrcalibrate -v -s response.m

Recover the response curve from set of exposures defined in
sample.hdrgen and save it to response.m file. To view the response
curve, run gnuplot and write 'plot "response.m"'.

.TP
pfsinhdrgen sample.hdrgen | pfshdrcalibrate -f response.m | pfsview

Create an HDR image from exposures defined in sample.hdrgen using the
response curve "response.m" and view it.

.TP
pfsinhdrgen sample.hdrgen | pfshdrcalibrate | pfsview

Create an HDR image from exposures defined in sample.hdrgen using the
default self-calibration method and view it.

.TP
pfsinhdrgen sample_dcraw.hdrgen | pfshdrcalibrate -b 16 -r linear -c none | pfsview

Given that the script sample_dcraw.hdrgen refers to camera RAW files
(see pfsindcraw), this example will generate an HDR image assuming a
linear response.

.TP
pfsinhdrgen sample.hdrgen | pfshdrcalibrate | pfsview

Create an HDR image from exposures defined in sample.hdrgen using the
default self-calibration method and view it.

.SH "SEE ALSO"
.BR pfsinhdrgen (1)
.BR jpeg2hdrgen (1)
.BR pfsview (1)
.BR pfsindcraw (1)
.BR pfsabsolute (1)
.SH BUGS
Please report bugs and comments on implementation to 
Grzegorz Krawczyk <gkrawczyk@users.sourceforge.net>.