In this paper, we report formulation and case study of the conditions for patenting processes of content-based retrieval in digital libraries, especially in image libraries. Inventors and practitioners demand formulation of the conditions for patenting the processes as computer-related programs in combining prior disclosed means, and also in comprising the means for parameter settings to perform certain functions. Content-based retrieval indexes the extracted features of images and classifies the indexes to perform its retrieval function.A process for content-based retrieval often consists of a combination of prior disclosed means. That process also comprises the means for parameter settings that are adjusted to retrieve a specific kind of image at a certain narrow domain. We formulate the conditions of patentability on processes for performing content-based retrieval in combining the prior disclosed means and/or comprising the means for parameter settings from the practical standpoints of technical advancement (nonobviousness) and specification (enablement).