This research presents an optical camera-based method for measuring narrow band and third-octave band spectra of the total flexural vibration and total sound radiation of 2D and 3D structures. The proposed method overcomes key issues inherent in classical vibro-acoustic measurements, such as the requirement of long-duration and full-field measurements and, to some extent, the need of physically masking flanking sources and background noise. Digital image correlation combined with frequency-domain triangulation is employed, which is particularly suited for the derivation of spectral measurements, although classical time-domain triangulation could be employed too. The narrow-band vibration and sound radiation spectra are derived from integral formulations. In particular, the total sound power radiation is derived using the radiation resistance matrix, which can be calculated from numerical quadrature of the boundary integral for the sound radiation. The third-octave band spectra are computed by integration of the narrow band spectra over appropriate frequency-bands. The proposed method is validated for a model prism box by contrasting the narrow band and third-octave band spectra of the total flexural vibration and total sound power radiation estimated from camera recordings with those obtained from direct measurements taken with a scanning laser vibrometer and a microphone array according to ISO 3744:2026 in a semi-anechoic room. The proposed approach offers a valid alternative to traditional vibro-acoustic measurements, which does not require expensive laboratory facilities and long-lasting and costly measurement campaigns, and can be effectively integrated as an in-situ acoustic design and monitoring tool.