Television – Format conversion – Changing number of fields for standard conversion
Reexamination Certificate
2000-01-27
2003-02-25
Miller, John (Department: 2614)
Television
Format conversion
Changing number of fields for standard conversion
C348S558000, C348S701000
Reexamination Certificate
active
06525774
ABSTRACT:
This application claims the benefit of Japanese Application No. 11-017846, filed in Japan on Jan. 27, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an inverse telecine converting device and an inverse telecine converting method for converting quasi television motion pictures produced from frame pictures of a cinema into frame pictures of the original cinema.
2. Description of the Related Art
With respect to television motion pictures, picture information of 30 frames per second (hereinafter referred to as “frame picture information” is time-sequentially displayed on a screen. As shown in
FIG. 1
, frame picture information
80
is constructed by combining top field picture information
81
and bottom field picture information
82
and then scanning both portions of the field picture information.
A conversion method shown in
FIG. 2
(hereinafter referred to as “telecine conversion”) has been hitherto utilized to produce video motion pictures for TV from a cinema film (24 frames per second) because the number of frames per second is different between the cinema and the TV formats. According to the conventional telecine conversion method, the frame picture information of a cinema (movie) is replaced as top field picture information (at the upper stage of the video field of
FIG. 2
) or bottom field picture information (at the lower stage of the video field of FIG.
2
).
Through this telecine conversion, one field picture information piece is inserted as repetitive field picture information every five field picture information pieces. There are two cases for the insertion of the repetitive field picture information. In one case, the just-previous top field picture information (the second preceding field picture information) is set as top field image information corresponding to the repetitive field picture information concerned. In the other case, the just-previous bottom field picture information (the second preceding field picture) is set as bottom field image information corresponding to the repetitive field picture information concerned. In the following description, the television motion picture information thus produced from the cinema film is referred to as “quasi television motion picture information”.
Recently, DVD (Digital Versatile Disk) has been rapidly developed and now being popularized in the market. The propagation of DVD has promoted the production of motion picture software (video contents) for DVD from conventional quasi television motion picture information. When motion picture software (video content) for DVD is produced from conventional quasi television motion picture information, it is indispensable to delete repetitive field picture information in the quasi television motion picture information and return the quasi television motion picture information to picture information of 24 frames per second (hereinafter referred to as “inverse telecine conversion”).
The importance of deleting the repetitive field information is two-fold. First, the picture information is subjected to compression (encoding) processing for DVDs. In this case, the compression efficiency is increased by returning quasi television motion picture information (30 frames per second) containing repetitive field picture information to original cinema motion picture information (24 frames per second) containing no redundant information and then compressing the original cinema motion picture information, as compared to directly compressing the quasi television motion picture information. Here, the image quality also is better with the repetitive field information removed for a specific amount of data. Second, when picture information is reproduced in a DVD reproducing device (player) while advancing frames, the frame advance of a cinema film can be directly implemented.
FIG. 3
is a conceptual diagram showing inverse telecine conversion in the conventional inverse telecine converting device.
As shown in
FIG. 3
, quasi television motion picture information (i.e., video frames at 30 frames per second) obtained from a telecine converted cinema film processing is input to an inverse telecine conversion device. Repetitive field picture information contained in the quasi television motion picture information is deleted as indicated by the dotted-line frame in
FIG. 3
, thereby converting the quasi television motion picture information to the picture information of a reproduced original movie film of 24 frames per second.
At the same time, control flags which are needed to re-convert the picture information of 24 frames per second to television picture information of 30 frames per second, are generated and added to the frames of the picture information of the original movie film thus reproduced. In
FIG. 3
, a control flag TFF controls to give priority to the top field picture information in the frame provided with the control flag TFF. A control flag BFF controls to give priority to the bottom field picture information in the frame provided with the control flag BFF. A control flag RFF controls to set the first field picture information in the frame concerned to the repetitive field picture information.
Next, the principle of conventional inverse telecine conversion will be described.
As described above, the insertion period and the insertion position of the repetitive field picture information pieces which are inserted through the conventional telecine conversion are determined in advance. A method of deleting the field picture information pieces located at predetermined positions every five fields using the above fact (hereinafter referred to as “fixed-period field deletion method”) is considered to be the simplest method. In the case of cinema, a cinema (movie) is normally composed of a set of plural film rolls. In this case, the picture information of each film roll is converted to television motion picture information. Then, the television motion picture information corresponding to the film rolls are joined together and edited to obtain one video tape. However, the top fields or bottom fields are usually displaced between the front and back sides at the place where the two portions are joined with respect to the joint places. Therefore, the period of the repetitive field picture information is deviated from the fixed period. Accordingly, if the fixed-period field deletion method is applied carelessly, originally-needed picture information that is not repetitive field picture information may be deleted.
FIG. 4
shows an inverse telecine converting method that has been conventionally used to solve the above problem. According to this method, the correlation between the pixel values of timely-adjacent top field picture information pieces and the correlation between the pixel values of timely-adjacent bottom field picture information pieces are checked over several frames of quasi television motion picture information obtained through the telecine conversion processing. Then, one of two field picture information pieces which are judged to be highly correlated with each other is regarded as repetitive field picture information and deleted.
In the conventional inverse telecine converting device shown in
FIG. 4
, however, in a case of pictures having a lot of noise or in a case of pictures of a scene having little motion, any field picture information piece will have high correlation in pixel value with another field picture information piece. Thus, it is difficult to identify which field picture information piece is repetitive field picture information.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a inverse telecine converting device and inverse telecine converting method that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide an inverse telecine converting device and an inverse telecine converting method that can identify repetitive field picture information for even pictures containing a lot of noise and pictures o
Miller John
Morgan & Lewis & Bockius, LLP
Pioneer Corporation
Yenke Brian
LandOfFree
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