Snímek 5245

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 18:33:20
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5245.pgm)
# Focal length :  5.7mm  (35mm equivalent: 39mm)
# 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   -65   -60   -61   -65        -4.67    -2.51    -4.24    -3.27  
 10   -27   -22   -23   -28        -1.94    -0.934   -1.83    -1.29  
 50    14    17    17     8         1.01     0.706    0.522    0.811 
 90   120   146   146    77         8.62     6.06     5.02     6.96  
 99   527   618   616   254         37.9     25.6     16.6     29.9  
100 15977 15974 15974 15975         1.15E3    663     1.04E3    833  
# flux from 0.654*0.74 sr ( 8.59E-7 sr/4px) is  1.68 lx ( 2.02 lx tilewise);
# tilewise luminance  2.91 cd/m2 with rel. SD  158 % (summing pixels below 15850 and with non-zero green: there is 73.6 % of them)
# Fuji Devignetting: 1 # dark frame dark/5238.pgm subtracted from all values
# Red  average=  62.4  minimum= -163  maximum=15977   over 15850: 315 zero: 26.1 %
# GrUp average=  76.8  minimum= -135  maximum=15974   over 15850: 298 zero: 26.4 %
# GrDw average=  76.3  minimum= -152  maximum=15974   over 15850: 301 zero: 26.3 %
# Blue average=  38.0  minimum= -164  maximum=15975   over 15850: 207 zero: 30.6 %

End of results of "raw2lum" (version 1.22) with parameters:
  -c fuji -fa -d dark/5238.pgm -nh -nt -i 5245.txt -t 118 -s71:76 pgm/5245.pgm

Just points with luminances over 40 and below 3.0E2 cd/m2. In grid tiles, flux densities from these points and tiles are given.
# Date/Time    : 2006:02:26 18:33:20
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5245.pgm)
# Focal length :  5.7mm  (35mm equivalent: 39mm)
# 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   -65   -60   -61   -65        -4.67    -2.51    -4.24    -3.27  
 10   -27   -22   -23   -28        -1.94    -0.934   -1.83    -1.29  
 50    14    17    17     8         1.01     0.706    0.522    0.811 
 90   120   146   146    77         8.62     6.06     5.02     6.96  
 99   527   618   616   254         37.9     25.6     16.6     29.9  
100 15977 15974 15977 15977         1.15E3    663     1.04E3    833  
# flux from 0.00269 sr ( 8.59E-7 sr/4px) is  0.209  lx (points with luminances over   40    and below  3.0E2 )
# Fuji Devignetting: 1 # dark frame dark/5238.pgm subtracted from all values
# Red  average=1688.2  minimum= -140  maximum=15977   over 15850: 762845
# GrUp average=1861.5  minimum= -135  maximum=15974   over 15850: 762828
# GrDw average=1893.2  minimum= -120  maximum=15974   over 15850: 762831
# Blue average=1249.3  minimum= -132  maximum=15975   over 15850: 762737

End of results of "raw2lum" (version 1.21) with parameters:
  -c fuji -ft -d dark/5238.pgm -sm100 -nh -L40 -U300 -i 5245.txt -e 5245.eps -n 5245.ppm -t 118 -s71:76 pgm/5245.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.