Proc. SPIE. 5150, Visual Communications and Image Processing 2003
KEYWORDS: Mathematical modeling, Principal component analysis, Statistical analysis, Visual process modeling, Video, Video processing, Algorithm development, Molybdenum, Systems modeling, RGB color model
This paper describes a model to estimate human subjective video quality scores based on a framework of double-ended with a full reference system or end-to-end network video systems where sending video and receiving videos are available. The model incorporates multi-dimensional and multi-variables all of which are objectively measurable. Its aim is to estimate subjective score in the difference mean opinion score between a reference video and corresponding degraded videos. The model is developed based on an application of the multivariable analysis and trained by a set of a priori known relationship between physically obtainable parameters and corresponding subjective score. The paper describes how the model incorporates a mathematical algorithm as an executable programme module, and in what degree the model can be applicable in order to account actual examples of video pairs for both training video set used and foreign video sets. Referring to an application of the developed model to a set of foreign videos, it reports the capability of the model to different quality range. In addition to the worked results, some issues for further study are highlighted.
Color signal outputs form digital cameras can be calculated form spectral distribution of an illumination, spectral reflectance of a shooting object, and spectral responsivity of a camera. The methods of measuring spectral distribution of illuminations and spectral reflectance of objects have been established unambiguously, and their characteristics are available from various databases. However, no accurate methods have been clearly defined regarding the measurement of the spectral responsivity characteristics of digital cameras. For objective assessment of the performance of digital cameras which capture color images and output corresponding color information in red-green-blue digital image data, proposed methods incorporate measurements of characteristics for spectral responsivity and related items. In this paper, by adopting compensation of tone characteristics for each pixel, the authors develop yet another new method of measurements to overcome some possible defects in the previously proposed methods. The paper describes an arrangement of equipment, definition of test chart and raw data handling together with some worked examples. The newly developed method has made it possible to measure the spectral responsivity characteristics of digital cameras accurately.
Recently, various kinds of multimedia application systems have actively been developed based on the achievement of advanced high sped communication networks, computer processing technologies, and digital contents-handling technologies. Under this background, this paper proposed a new distributed multimedia database system which can effectively perform a new function of cooperative retrieval among distributed databases. The proposed system introduces a new concept of 'Retrieval manager' which functions as an intelligent controller so that the user can recognize a set of distributed databases as one logical database. The logical database dynamically generates and performs a preferred combination of retrieving parameters on the basis of both directory data and the system environment. Moreover, a concept of 'domain' is defined in the system as a managing unit of retrieval. The retrieval can effectively be performed by cooperation of processing among multiple domains. Communication language and protocols are also defined in the system. These are used in every action for communications in the system. A language interpreter in each machine translates a communication language into an internal language used in each machine. Using the language interpreter, internal processing, such internal modules as DBMS and user interface modules can freely be selected. A concept of 'content-set' is also introduced. A content-set is defined as a package of contents. Contents in the content-set are related to each other. The system handles a content-set as one object. The user terminal can effectively control the displaying of retrieved contents, referring to data indicating the relation of the contents in the content- set. In order to verify the function of the proposed system, a networked electronic museum was experimentally built. The results of this experiment indicate that the proposed system can effectively retrieve the objective contents under the control to a number of distributed domains. The result also indicate that the system can effectively work even if the system becomes large.
This paper proposes a new approach to automatically extract an accurate object from video streams. The new approach provides a useful tool creating linking information for a distributed movie-based Web-browsing system, and consists of a skip- labeling algorithm for feature-based segmentation, and a shrink-merge tracking algorithm for tracking an object. This skip-labeling algorithm can be used to segment an image into integrated regions of the same feature. The segmented regions belong to such a texture area as waves or forest. The shrink- merge tracking algorithm is executed, based on the time continuity of moving-objects, using morphological image processing, such as dilation and erosion. The dilation and erosion are repeatedly executed using the projection processing in which the object area in a next frame is derived from the object area in a current frame. The shrink-merge tracking algorithm can also project the area of a rotating- object in a current frame on the rotating-object containing the newly appearing regions in the next frame. The newly automated object extraction method works satisfactorily for the objects which move non-linearly within the video streams including MPEG and Motion JPEG, and works satisfactorily in approximately 450 frames, each with a full frame size of 704 X 480 pixels at video frame rate of 30 fps. This paper finally demonstrates that object-based linking information for a movie-based Web-browsing system contains information of objects obtained by the fully automated extraction from video- streams.
The authors have newly developed measuring methods to assess and characterize color reproduction of digital still cameras and digital video cameras which capture color images and output corresponding color information in red, green, blue digital image data, the proposed new methods incorporate spectral responsivity characteristics measurements and other characteristics measurements. They are made possible by using newly developed test charts with a dark box and a spectral light source. The proposed set up for the measurements is specially effective to eliminate the influence of automatic functions commonly equipped in digital cameras for low-end consumer use. In this paper, arrangement of measurement equipment, definition of test charts, and raw data handling are described together with worked examples.
This paper proposes a new distributed multimedia data base system where the databases storing MPEG-2 videos and/or super high definition images are connected together through the B-ISDN's, and also refers to an example of the networking of museums on the basis of the proposed database system. The proposed database system introduces a new concept of the 'retrieval manager' which functions an intelligent controller so that the user can recognize a set of image databases as one logical database. A user terminal issues a request to retrieve contents to the retrieval manager which is located in the nearest place to the user terminal on the network. Then, the retrieved contents are directly sent through the B-ISDN's to the user terminal from the server which stores the designated contents. In this case, the designated logical data base dynamically generates the best combination of such a retrieving parameter as a data transfer path referring to directly or data on the basis of the environment of the system. The generated retrieving parameter is then executed to select the most suitable data transfer path on the network. Therefore, the best combination of these parameters fits to the distributed multimedia database system.