1. A method of detecting an anomaly in an image captured in vivo by an in-vivo imaging system, the method comprising: segmenting an image captured in vivo into valid tissue zones for anomaly detection, and non-valid tissue zones excluded from anomaly detection, wherein each valid tissue zone is a portion of the image, wherein each pixel in the valid tissue zone has a pixel intensity value that is greater than a predetermined intensity reference value, and wherein each pixel in the valid tissue zone is associated with a respective set of imaging parameter values, the set of imaging parameter values having a deviation from a corresponding reference value no greater than a predefined deviation; identifying, in the valid tissue zones, individual pixels whose color characteristics deviate from reference color parameters representing normal tissue, and classifying said pixels as anomaly pixels; and analyzing each identified valid tissue zone by: (i) identifying a group of the individual anomaly pixels in the valid tissue zone; (ii) if the group of anomaly pixels in the valid tissue zone satisfies predetermined anomaly criteria, determining that a region of the zone containing the group of anomaly pixels is an anomaly region; and repeating steps (i) and (ii) for all anomaly pixels identified in the valid tissue zone.