Snímek 5153

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 21:40:17
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5153.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   -72   -68   -69   -71        -82.8    -45.5    -74.1    -58.5  
 10   -36   -33   -33   -35        -41.4    -21.9    -36.5    -28.7  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    37    35    35    36         42.5     23.3     37.6     30.0  
 99    75    72    72    73         86.2     47.8     76.1     61.3  
100 15985 15982 15982 15983         1.84E4   1.06E4   1.67E4   1.33E4
# flux from 0.654*0.51 sr ( 8.59E-7 sr/4px) is  0.708 lx ( 1.56 lx tilewise);
# tilewise luminance  2.22 cd/m2 with rel. SD  340 % (summing pixels below 15850 and with non-zero green: there is 50.9 % of them)
# Fuji Devignetting: 1 # dark frame dark/5154.pgm subtracted from all values
# Red  average=   2.5  minimum= -146  maximum=15985   over 15850:  33 zero: 44.8 %
# GrUp average=   3.4  minimum= -140  maximum=15982   over 15850:  45 zero: 49.4 %
# GrDw average=   3.5  minimum= -148  maximum=15982   over 15850:  48 zero: 48.7 %
# Blue average=   2.6  minimum= -155  maximum=15983   over 15850:  32 zero: 47.1 %

End of results of "raw2lum" (version 1.22) with parameters:
  -c fuji -fa -d dark/5154.pgm -nh -nt -i 5153.txt -t 118 -s71:76 pgm/5153.pgm

Just points with luminances over 5.0E2 cd/m2. In grid tiles, flux densities from these points and tiles are given.
# Date/Time    : 2006:02:24 21:40:17
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5153.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   -71   -67   -68   -70        -81.6    -44.8    -73.0    -57.7  
 10   -35   -32   -33   -34        -40.2    -21.6    -35.5    -28.1  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    37    35    35    36         42.5     23.3     37.6     30.0  
 99    75    72    73    73         86.2     48.2     76.1     61.5  
100 15985 15985 15985 15985         1.84E4   1.06E4   1.67E4   1.33E4
# flux from 1.33E-4 sr ( 8.59E-7 sr/4px) is  0.257  lx (points with luminances over  5.0E2 )
# Fuji Devignetting: 1 # dark frame dark/5119.pgm subtracted from all values
# Red  average=2719.8  minimum= -120  maximum=15985   over 15850: 765918
# GrUp average=3374.0  minimum= -125  maximum=15982   over 15850: 765930
# GrDw average=3051.5  minimum= -138  maximum=15982   over 15850: 765933
# Blue average=2891.9  minimum= -123  maximum=15983   over 15850: 765917

End of results of "raw2lum" (version 1.21) with parameters:
  -c fuji -ft -d dark/5119.pgm -sm100 -nh -L500 -i 5153.txt -e 5153.eps -n 5153.ppm -t 118 -s71:76 pgm/5153.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.