Snímek 5146

původní zesvětlený barevně kódovaný

a ještě s vloženou mřížkou s údaji:

(údaj uprostřed políček mřížky je medián surových hodnot zelených pixelů, údaj dole je jas políčka dělený jednou kandelou na metr čtvereční).
# Date/Time    : 2006:02:24 20:35:52
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5146.pgm)
# Focal length : 12.0mm  (35mm equivalent: 81mm)
# CCD width    : 5.32mm
# Exposure time: 0.008 s  (1/125)
# Aperture     : f/2.8
# ISO equiv.   : 200

# Selected image percentils         L=(1.730*0.35*R+1.000*0.65*G+1.570*0.00*B)* 0.0415
# %    R     G1    G2    B readings  R        G        B        L / cd/m2
  1   -71   -67   -68   -69        -5.10    -2.80    -4.50    -3.61  
 10   -35   -31   -32   -34        -2.51    -1.31    -2.22    -1.73  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    40    39    40    38         2.87     1.64     2.48     2.07  
 99    94   132   131    87         6.75     5.46     5.67     5.91  
100 15869 15866 15866 15867         1.14E3    659     1.03E3    827  
# flux from 0.148*0.52 sr ( 1.94E-7 sr/4px) is  0.0316 lx ( 0.0498 lx tilewise);
# tilewise luminance  0.289 cd/m2 with rel. SD  364 % (summing pixels below 15850 and with non-zero green: there is 52.2 % of them)
# Fuji Devignetting: 2 # dark frame dark/5119.pgm subtracted from all values
# Red  average=   5.9  minimum= -151  maximum=15869   over 15850:  23 zero: 43.6 %
# GrUp average=  10.3  minimum= -149  maximum=15866   over 15850:  29 zero: 48.6 %
# GrDw average=  10.1  minimum= -142  maximum=15866   over 15850:  33 zero: 47.1 %
# Blue average=   5.6  minimum= -148  maximum=15867   over 15850:  46 zero: 46.3 %

End of results of "raw2lum" (version 1.22) with parameters:
  -c fuji -fa -d dark/5119.pgm -nh -nt -i 5146.txt -t 118 -s71:76 pgm/5146.pgm

Just points with luminances over 25 and below 5.0E2 cd/m2. In grid tiles, flux densities from these points and tiles are given.
# Date/Time    : 2006:02:24 20:35:52
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5146.pgm)
# Focal length : 12.0mm  (35mm equivalent: 81mm)
# CCD width    : 5.32mm
# Exposure time: 0.008 s  (1/125)
# Aperture     : f/2.8
# ISO equiv.   : 200


# Selected image percentils         L=(1.730*0.35*R+1.000*0.65*G+1.570*0.00*B)* 0.0415
# %    R     G1    G2    B readings  R        G        B        L / cd/m2
  1   -71   -67   -68   -69        -5.10    -2.80    -4.50    -3.61  
 10   -35   -31   -32   -34        -2.51    -1.31    -2.22    -1.73  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    40    39    40    38         2.87     1.64     2.48     2.07  
 99    94   132   131    87         6.75     5.46     5.67     5.91  
100 15869 15869 15866 15867         1.14E3    659     1.03E3    827  
# flux from 7.52E-5 sr ( 1.94E-7 sr/4px) is  0.00404 lx (points with luminances over   25    and below  5.0E2 )
# Fuji Devignetting: 2 # dark frame dark/5119.pgm subtracted from all values
# Red  average=1210.3  minimum= -127  maximum=15869   over 15850: 765686
# GrUp average=1633.1  minimum= -128  maximum=15866   over 15850: 765692
# GrDw average=1510.1  minimum= -142  maximum=15866   over 15850: 765696
# Blue average=1651.1  minimum= -133  maximum=15867   over 15850: 765709

End of results of "raw2lum" (version 1.21) with parameters:
  -c fuji -ft -d dark/5119.pgm -sm100 -nh -L25 -U500 -i 5146.txt -e 5146.eps -n 5146.ppm -t 118 -s71:76 pgm/5146.pgm

skala jasu / 1 
cd/m<sup>2</sup>
Logaritmická škála jasů (jednotkou je kandela na metr čtvereční, nazývaná též nit) – intenzity osvětlení sněhu v luxech dostanete vynásobením jasu v nitech koeficientem 3,6. U intenzit osvětlení lesní stěny je takový koeficient 20 až 40.