Snímek 5244

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 18:33:10
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5244.pgm)
# Focal length :  5.7mm  (35mm equivalent: 39mm)
# 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   -35   -31   -32   -34        -40.2    -20.9    -35.5    -27.7  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    39    36    37    36         44.8     24.3     37.6     31.5  
 99    78    77    77    74         89.7     51.2     77.2     64.6  
100 15977 15974 15951 15959         1.84E4   1.06E4   1.66E4   1.33E4
# flux from 0.654*0.52 sr ( 8.59E-7 sr/4px) is  1.71 lx ( 3.45 lx tilewise);
# tilewise luminance  4.86 cd/m2 with rel. SD  235 % (summing pixels below 15850 and with non-zero green: there is 52.2 % of them)
# Fuji Devignetting: 1 # dark frame dark/5238.pgm subtracted from all values
# Red  average=   5.7  minimum= -163  maximum=15977   over 15850:  36 zero: 43.4 %
# GrUp average=   7.1  minimum= -140  maximum=15974   over 15850:  39 zero: 48.5 %
# GrDw average=   6.9  minimum= -152  maximum=15951   over 15850:  47 zero: 47.2 %
# Blue average=   3.9  minimum= -178  maximum=15959   over 15850:  12 zero: 46.7 %

End of results of "raw2lum" (version 1.22) with parameters:
  -c fuji -fa -d dark/5238.pgm -nh -nt -i 5244.txt -t 118 -s71:76 pgm/5244.pgm

Just points with luminances over 3.0E2 and below 5.0E3 cd/m2. In grid tiles, flux densities from these points and tiles are given.
# Date/Time    : 2006:02:26 18:33:10
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5244.pgm)
# Focal length :  5.7mm  (35mm equivalent: 39mm)
# 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   -35   -31   -32   -34        -40.2    -20.9    -35.5    -27.7  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    39    36    37    36         44.8     24.3     37.6     31.5  
 99    78    77    77    74         89.7     51.2     77.2     64.6  
100 15977 15974 15951 15977         1.84E4   1.06E4   1.67E4   1.33E4
# flux from 4.22E-4 sr ( 8.59E-7 sr/4px) is  0.515  lx (points with luminances over  3.0E2  and below  5.0E3 )
# Fuji Devignetting: 1 # dark frame dark/5238.pgm subtracted from all values
# Red  average=1757.3  minimum= -140  maximum=15977   over 15850: 765586
# GrUp average=1849.6  minimum= -136  maximum=15974   over 15850: 765589
# GrDw average=1796.5  minimum= -122  maximum=15951   over 15850: 765597
# Blue average=1220.2  minimum= -155  maximum=15959   over 15850: 765562

End of results of "raw2lum" (version 1.21) with parameters:
  -c fuji -ft -d dark/5238.pgm -sm100 -nh -L300 -U5000 -i 5244.txt -e 5244.eps -n 5244.ppm -t 118 -s71:76 pgm/5244.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.