Table 1 Summary for all the symbols that are used in the text

λ

Wavelength

λ _x

Excitation wavelength

λ _m

Emission wavelength

ϕ

Quantum yield

ε

Molar absorptivity

M

Molecular weight

f _x

Fluorophore excitation spectrum

f _m

Fluorophore emission spectrum

L _ve

Self-emission radiance at point p

L _s

Radiance due to scattering

L _i

Incoming radiance to point p

L _e

Outgoing radiance emitted from the light source

x _n

Point on the light source for a path consisting of n points

x ₀

Point on the surface of the virtual film of the camera

x _i /x _j

Point along the path after i or j bounces

\(\overline {x}\)

Path connecting the camera and light source

C

Concentration

ω

Direction

ω ^′

Incoming direction

F _s

Scattering function

G

Geometry term

V

Binary Visibility

\(V_{f_{i}}\)

Path Binary Fluorescence Visibility

τ

Transmittance

\(\hat {V}\)

Visibility term

σ _s

Scattering coefficient

σ

Absorption coefficient

f _p

Phase function

p _x

Photon excitation (or absorption) probability

p _m

Photon emission probability