Retrieval of landscape images and automatic index generation by using object sketches.

This paper proposes a method of retrieving landscape images in which an index is first generated automatically and then, to enable retrieval even when the index includes errors, a pixel-based object labeling technique for the landscape images is employed and similar images are retrieved by using object sketches. The automatic index generation requires recognition processing. Outdoor images are conventionally recognized by using a segment-based approach and heuristic knowledge and, as a consequence, problems of segment generation and knowledge acquisition arise. The proposed recognition method employs pixel-based, independent processing which does not use heuristic knowledge and, therefore, compared with conventional techniques for recognizing outdoor scenes, the process of index generation can be automated more easily. Generally, it is not possible to avoid errors completely in recognition results. With respect to this problem, this paper proposes a retrieval method using object sketches in which the user specifies object types and their position inside the image. Based on experiments, it is shown that, when this method is combined with a pixel-based object labeling technique, it is possible to retrieve with approximately the same degree of accuracy as when using a similar index built by humans, even when the recognition results are partially wrong. © 1999 Scripta Technica, Syst Comp Jpn, 30(12): 85–94, 1999 [ABSTRACT FROM AUTHOR]