This paper describes a method for integrating a frequency-dependent object characterization into a practical sonar imaging system. Integration of joint time-frequency (JTF) processing into broadband SAS imaging enables one to add another dimension (frequency) to the object feature space without compromising resolution. JTF processing enables a user to construct a 3-D image description around objects of interest. The Gabor transform is used to capture the local frequency behavior in the image. The Gabor coefficients are used to reconstruct multispectral images.