Image analysis – Image transformation or preprocessing – Measuring image properties
Reexamination Certificate
1999-11-23
2003-11-04
Johns, Andrew W. (Department: 2621)
Image analysis
Image transformation or preprocessing
Measuring image properties
C382S293000, C382S295000, C382S243000, C382S103000, C382S232000, C382S199000
Reexamination Certificate
active
06643414
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to image processing methods, image processing apparatuses, and data storage media and, more particularly, to a coding process for superposing secret information on an image signal corresponding to each object and then coding the image signal. The invention also relates to a decoding process adapted to the coding process.
BACKGROUND OF THE INVENTION
In recent years, we have greeted the age of multimedia in which audio, video, and other data are integrally handled, and the conventional information media, i.e., means for transmitting information to men, such as newspapers, magazines, televisions, radios, and telephones, have been adopted as the targets of multimedia. Generally, “multimedia” means media in which, not only characters, but also diagrams, speeches, and especially images are simultaneously expressed in relation with each other. In order to handle the conventional information media as the targets of multimedia, it is necessary to express the information in digital formats.
When the quantity of data possessed by each of the above-described information media is estimated as the quantity of digital data, in the case of characters, the data quantity per character is only 1~2 byte. However, in the case of speech, the data quantity is 64 kbits per second (quality for telecommunication). Further, in the case of moving picture, the required data quantity is more than 100 Mbits per second (quality for current television broadcasting). So, in the above-described information media, it is not practical to handle such massive data as it is in the digital format. For example, although visual telephones have already been put to practical use by the ISDN (Integrated Services Digital Network) having a transmission rate of 64 kbps~1.5 Mbps, it is impossible to transmit an image from a television camera as it is by the ISDN.
So, data compression techniques are demanded. For example, for visual telephones, the moving picture compression techniques based on the H.261 and H.263 standards which have been standardized by ITU-T (International Telecommunication Union—Telecommunication Sector) are employed. Further, according to the data compression technique based on the MPEG1 standard, it is possible to record image data as well as audio data in an ordinary music CD (compact disk).
The MPEG (Moving Picture Experts Group) is an international standard of data compression for moving pictures, and the MPEG1 is the standard for compressing moving picture data to 1.5 Mbps, i.e., data of a television signal to about {fraction (1/100)}. Since the transmission rate of the targets to which the MPEG1 standard is directed is limited to about 1.5 Mbps, in the MPEG2 which has been standardized to meet the demand for higher image quality, moving picture data is compressed to 2~15 Mbps.
Furthermore, under the existing circumstances, standardization of MPEG4 is now proceeded by the working group for standardization of MPEG1 and MPEG2 (ISO/IEC JTC1/SC29/WG11), and this MPEG4 enables coding and signal processing in object units, and thereby realizes new functions required in the age of multimedia.
The MPEG4 has originally aimed at standardization of coding methods of low bit rates, but the target of standardization is now extended to more versatile coding methods of higher bit rates which are adaptable to an interlace image.
FIGS.
13
(
a
)-
13
(
d
) are diagrams for explaining the object-by-object coding process.
FIG.
13
(
a
) shows a composite image G corresponding to one frame in which three objects (i.e., fish, seaweed, and background) are composited.
In the object-by-object coding process, image signals corresponding to the respective objects constituting the composite image G, i.e., the background B (FIG.
13
(
b
)), the fish F
1
as a first foreground (FIG.
13
(
c
)), and the seaweed F
2
as a second foreground (FIG.
13
(
d
)) are coded individually. Then, coded image signals corresponding to the respective objects are individually transmitted through a transmission medium or recorded in a recording medium.
On the other hand, in the object-by-object decoding process, the coded image signals corresponding to the respective objects are individually received through the transmission medium or reproduced from the recording medium. The coded image signals so obtained are decoded object by object to generate decoded image signals corresponding to the respective objects. Then, the decoded image signals corresponding to the respective objects are composited to obtain a decoded image signal corresponding to the composite image (decoded and reproduced image) G.
In the object-by-object coding process, together with the coded image signals obtained by coding the image signals corresponding to the respective objects, information (scene information) indicating the locations of the respective objects in one frame (display area of the composite image) for compositing the respective objects to be displayed is also transmitted through the transmission medium or recorded on the recording medium.
FIG. 14
is a diagram for specifically explaining information which is used as coding parameters in the object-by-object coding process.
In the object-by-object coding process, the following are coded for transmission or recording: pixel values (image signal) within an object area (hereinafter referred to as a rectangle area (BBOX)) including one object (e.g., the first foreground F
1
); size information (OBJsize) indicating the size (range) of the rectangle area; area position information (OBJpos) indicating the position of the rectangle area in an object coordinate system (individual coordinate system) corresponding to each object; and coordinate position information (FMpos) indicating the positional relationship between a composite image coordinate system (whole coordinate system) corresponding to a composite image and the object coordinate system corresponding to the object.
The object coordinate system (individual coordinate system) is a coordinate system used for coding of the image signal corresponding to the rectangle area, and it defines a display area corresponding to each object (VOP: Video Object Plane). Further, the composite image coordinate system (whole coordinate system) is a coordinate system used for composition of the respective objects, and it defines a display area (frame) F for displaying the whole composite image. Further, the size information (OBJsize) comprises the width and height of the rectangle area (BBOX). The area position information (OBJpos) is a position vector which indicates the direction and distance of a reference point or of the rectangle area (a point in the upper-left corner of the rectangle area) on the basis of an origin ob of the object coordinate system. The coordinate position information (FMpos) is a position vector which indicates the direction and distance of the origin Ob of the object coordinate system on the basis of an origin Og of the composite image coordinate system.
Since the area position information (OBJpos) is position information in the object coordinate system, it cannot be treated independently of the object-by-object coding process. However, since the coordinate position information (FMpos) is position information in the composite image coordinate system, it can be treated independently of the object-by-object coding process.
The purpose of representing the position of each object (i.e., the rectangle area) by using both of the area position information and the coordinate position information is to enable reuse and control of the object-by-object coded signals, in object units, without decoding the coded signals.
FIG. 15
is a block diagram for explaining the entire structure of a conventional image coding apparatus
200
a.
This image coding apparatus
200
a
encodes, object by object, image signals o
1
a
, o
1
b
, and o
1
c
respectively corresponding to the background B, the first foreground F
1
, and the second foreground F
2
which constitute the composite image G corresponding to one frame (display area of
Alavi Amir
Johns Andrew W.
LandOfFree
Image processing method, image processing apparatus, and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image processing method, image processing apparatus, and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image processing method, image processing apparatus, and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3184316