Snímek 5266

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 20:00:55
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5266.pgm)
# Focal length : 19.2mm  (35mm equivalent: 130mm)
# CCD width    : 5.32mm
# Exposure time: 0.001 s  (1/2000)
# Aperture     : f/3.2
# ISO equiv.   : 200

# Selected image percentils         L=(1.730*0.35*R+1.000*0.65*G+1.570*0.00*B)* 0.868
# %    R     G1    G2    B readings  R        G        B        L / cd/m2
  1   -70   -67   -67   -68         -105    -58.1    -92.6    -74.6  
 10   -35   -32   -32   -33        -52.5    -27.8    -45.0    -36.4  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    35    32    32    33         52.5     27.8     45.0     36.4  
 99    70    66    67    68          105     57.7     92.6     74.3  
100  5557  5897  8091  1950         8.34E3   6.07E3   2.66E3   6.87E3
# flux from 0.0580*0.48 sr ( 7.57E-8 sr/4px) is -0.00251 lx (-0.00638 lx tilewise);
# tilewise luminance -0.0395 cd/m2 with rel. SD-4.40E3 % (summing pixels below 15850 and with non-zero green: there is 48.4 % of them)
# Fuji Devignetting: 2 # dark frame dark/5276.pgm subtracted from all values
# Red  average=  -0.1  minimum= -151  maximum= 5557   over 15850:   0 zero: 46.5 %
# GrUp average=  -0.2  minimum= -146  maximum= 5897   over 15850:   0 zero: 51.9 %
# GrDw average=   0.0  minimum= -147  maximum= 8091   over 15850:   0 zero: 51.2 %
# Blue average=  -0.1  minimum= -143  maximum= 1950   over 15850:   0 zero: 48.8 %

End of results of "raw2lum" (version 1.22) with parameters:
  -c fuji -fa -d dark/5276.pgm -nh -nt -i 5266.txt -t 118 -s71:76 pgm/5266.pgm

Just points with luminances over 5.0E2 cd/m2. In grid tiles, flux densities from these points and tiles are given.
# Date/Time    : 2006:02:26 20:00:55
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/5266.pgm)
# Focal length : 19.2mm  (35mm equivalent: 130mm)
# CCD width    : 5.32mm
# Exposure time: 0.001 s  (1/2000)
# Aperture     : f/3.2
# ISO equiv.   : 200


# Selected image percentils         L=(1.730*0.35*R+1.000*0.65*G+1.570*0.00*B)* 0.868
# %    R     G1    G2    B readings  R        G        B        L / cd/m2
  1   -70   -67   -67   -68         -105    -58.1    -92.6    -74.6  
 10   -35   -32   -32   -33        -52.5    -27.8    -45.0    -36.4  
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    35    32    32    33         52.5     27.8     45.0     36.4  
 99    70    66    67    68          105     57.7     92.6     74.3  
100  8091  8091  8091  8091         1.21E4   7.02E3   1.10E4   8.81E3
# flux from 1.59E-6 sr ( 7.57E-8 sr/4px) is  0.00261 lx (points with luminances over  5.0E2 )
# Fuji Devignetting: 2 # dark frame dark/5276.pgm subtracted from all values
# Red  average=1486.4  minimum= -132  maximum= 5557   over 15850: 766091 zero:  4.8 %
# GrUp average=1220.9  minimum= -128  maximum= 5897   over 15850: 766091
# GrDw average=1986.3  minimum= -111  maximum= 8091   over 15850: 766091
# Blue average= 437.1  minimum= -122  maximum= 1950   over 15850: 766091

End of results of "raw2lum" (version 1.21) with parameters:
  -c fuji -ft -d dark/5276.pgm -sm100 -nh -L500 -i 5266.txt -e 5266.eps -n 5266.ppm -t 118 -s71:76 pgm/5266.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.