  In the framework of the relativistic and gauge invariant spectral integral
technique, we calculate radiative decays rho(770)-> gamma pi(140) and
omega(780)-> gamma pi(140) supposing all mesons (pi, rho and omega) to be
quark-antiquark states. The q anti-q wave functions found for mesons and photon
lead to a reasonably good description of data ($\Gamma^{(exp)}_{\rho^{\pm}
\to\gamma\pi^{\pm}}=68\pm 30$ keV,
$\Gamma^{(exp)}_{\rho^{0}\to\gamma\pi^0}=77\pm 28$ keV,
$\Gamma^{(exp)}_{\omega\to\gamma\pi^0}=776\pm 45$ keV) that makes it possible
to estimate the coupling for the bremsstrahlung emission of pion by quarks
$g_\pi\equiv g_\pi (u\to d \pi)$. We have found two values for the pion
bremsstrahlung coupling: $|g_\pi|=16.7 \pm 0.3 ^{+0.1}_{-2.3}$ (Solution I) and
$|g_\pi|=3.0 \pm 0.3 ^{+0.1}_{-2.1}$ (Solution II). Within SU(6)-symmetry for
nucleons, Solution I gives us for pi NN coupling the value $16.4 \le g_{\pi
NN}^2/(4\pi) \le 23.2$ that is in qualitative agreement with the pi N
scattering data, $g_{\pi NN}^2/(4\pi)\simeq 14$. For excited states, we have
estimated the partial widths in Solution I as follows: $\Gamma
(\rho_{2S}^\pm\to \gamma\pi)\simeq 10 - 130$ keV, $\Gamma (\rho_{2S}^0\to
\gamma\pi)\simeq 10 -130$ keV, $\Gamma (\omega_{2S}\to \gamma\pi)\simeq 60 -
1080$ keV. The large uncertainties emphasise the necessity to carry out
measurements of the meson radiative processes in the region of large masses.
