Snímek 5239

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    : 2006:02:26 18:21:48
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5239.pgm)
# Focal length :  7.5mm  (35mm equivalent: 51mm)
# CCD width    : 5.32mm
# Exposure time: 0.001 s  (1/2000)
# 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)* 0.664
# %    R     G1    G2    B readings  R        G        B        L / cd/m2
  1   -70   -66   -67   -69        -80.5    -44.2    -72.0    -56.9  
 10   -34   -31   -32   -33        -39.1    -20.9    -34.4    -27.3  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    39    37    38    37         44.8     24.9     38.6     31.9  
 99    79    78    79    75         90.8     52.2     78.2     65.7  
100 15869 15866 15866 15867         1.82E4   1.05E4   1.66E4   1.32E4
# flux from 0.379*0.52 sr ( 4.96E-7 sr/4px) is  1.62 lx ( 3.14 lx tilewise);
# tilewise luminance  7.42 cd/m2 with rel. SD  309 % (summing pixels below 15850 and with non-zero green: there is 52.4 % of them)
# Fuji Devignetting: 1 # dark frame dark/5238.pgm subtracted from all values
# Red  average=   9.9  minimum= -149  maximum=15869   over 15850:  66 zero: 43.2 %
# GrUp average=  11.4  minimum= -140  maximum=15866   over 15850:  90 zero: 47.9 %
# GrDw average=  11.5  minimum= -145  maximum=15866   over 15850:  76 zero: 47.3 %
# Blue average=   6.7  minimum= -153  maximum=15867   over 15850:   6 zero: 46.5 %

End of results of "raw2lum" (version 1.22) with parameters:
  -c fuji -fa -d dark/5238.pgm -nh -nt -i 5239.txt -t 118 -s71:76 pgm/5239.pgm

Just points with luminances over 6.0E2 and below 5.0E3 cd/m2. In grid tiles, flux densities from these points and tiles are given.
# Date/Time    : 2006:02:26 18:21:48
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5239.pgm)
# Focal length :  7.5mm  (35mm equivalent: 51mm)
# CCD width    : 5.32mm
# Exposure time: 0.001 s  (1/2000)
# 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)* 0.664
# %    R     G1    G2    B readings  R        G        B        L / cd/m2
  1   -70   -66   -67   -69        -80.5    -44.2    -72.0    -56.9  
 10   -34   -31   -32   -33        -39.1    -20.9    -34.4    -27.3  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    39    37    38    37         44.8     24.9     38.6     31.9  
 99    79    78    79    75         90.8     52.2     78.2     65.7  
100 15869 15866 15866 15867         1.82E4   1.05E4   1.66E4   1.32E4
# flux from 2.79E-4 sr ( 4.96E-7 sr/4px) is  0.523  lx (points with luminances over  6.0E2  and below  5.0E3 )
# Fuji Devignetting: 1 # dark frame dark/5238.pgm subtracted from all values
# Red  average=2942.6  minimum= -125  maximum=15869   over 15850: 765495
# GrUp average=2731.7  minimum= -137  maximum=15866   over 15850: 765519
# GrDw average=3076.7  minimum= -118  maximum=15866   over 15850: 765505
# Blue average=1961.1  minimum= -153  maximum=15867   over 15850: 765435

End of results of "raw2lum" (version 1.21) with parameters:
  -c fuji -ft -d dark/5238.pgm -sm100 -nh -L600 -U5000 -i 5239.txt -e 5239.eps -n 5239.ppm -t 118 -s71:76 pgm/5239.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.