Patent Application
20090190029
The present invention relates to a video processing scheme, and more particularly to video processing methods and related apparatuses for performing different video processing operations based on scan lines and blocks.
In general, a conventional video processing apparatus comprises a de-interlace processing module for converting an interlaced video into a progressive video. In order to correctly process the interlaced video, the de-interlace processing module needs to execute video detection, such as a motion detection or a film mode detection, before converting the interlaced video into progressive video. To cancel motion judder effects, a motion compensation module is used for processing the progressive video to cancel judder artifacts therein. The motion compensation module also execute video detection, e.g. the above-mentioned motion detection and film mode detection, to acquire information used to cancel motion judder artifacts. De-interface is typically processed line by line, so the above-mentioned video detection executed by a de-interlace processing module is usually a line-based video detection. Motion compensation on the other hand is typically processed block by block, and thus video detection executed by a motion compensation module is usually a block-based video detection.
More particularly, the de-interlace processing module converts interlaced video having a string of interlaced top and bottom fields into progressive video. The interlaced video may be a normal video or a film mode video, the de-interlace processing module executes video detection in order to process the interlaced video according to detection results. Regarding the motion compensation module, in general, a movie, film mode video, or an animation has a sampling rate of approximately 24-30 frames per second. However, the display frame rate of a display device is usually 50-60 frames per second or higher. Thus, the motion compensation module converts the progressive video having a lower frame rate (e.g. 30 frames per second) into a progressive video having a higher frame rate (e.g. 60 frames per second) for displaying on a common display device. Conventional frame rate conversion is achieved by duplicating certain frames of the original progressive video. For instance, when converting a video having 30 frames per second into a video having 60 frames per second, a duplication of each frame is immediately interpolated into the original video. In another example, converting a video having 24 frames per second into a video having 60 frames per second is more complex since some frames are repeated twice while other frames are repeated only once. In some cases, a progressive video outputted from the de-interlace module may have 60 frames per second, where the progressive video is generated inherently by repeating frames in an original video of 24/30 Hz. Although videos inputted to and outputted from the motion compensation module have 60 frames per second, the motion compensation module needs to execute film mode detection upon the progressive video and then uses the result of film mode detection to recover the original video of 24/30 Hz from the progressive video. Afterwards, the motion compensation module performs corresponding operation to achieve frame rate conversion according to the recovered video. The definition of motion compensation is usually referred as to “Motion Compensated Frame rate conversion and Film mode detection/recovery”, i.e. motion judder cancellation.
Motion judder effects are the consequence due to the above-described duplications. The so-called motion judder effects refer to unsmooth motion of object across frames. Please refer to
An objective of the present invention is to provide a video processing method and related apparatus for sharing information of line-based and block-based detection results to decrease the computation amount and to achieve more robust video detection.
According to an embodiment of the present invention, a video processing method comprises conducting a first video detection for a first video processing operation; and performing a second video processing operation with reference to a detection result of the first video detection; wherein one of the first and second video processing operation is a line-based processing, and the other is a block-based processing. In some other embodiments, the method further comprising conducting a second video detection for the second video processing operation, thereby the second video processing operation is executed by referring to either or both the detection results of first video detection and second video detection. The first video processing operation of one embodiment refers to either or both the detection results of first video detection and second video detection.
In some embodiments, the video processing method comprises determining a target detection result according to the detection results of first video detection and second video detection, and performing the first video processing operation according to the target detection result.
According to an embodiment of the present invention, a video processing apparatus comprises a first video processing module and a second video processing module. The first video processing module comprises a first video detector, and processes a video signal with reference to a detection result of the first video detector. The second video processing module is coupled to the first video processing module and receives the detection result of the first video detector as information for processing the video signal. One of the first and second video processing modules is operated in a line-based detection, and the other is operated in a block-based detection. In some embodiments, the second video processing module comprises a second video detector and the second video processing module also refers to the detection result of the second video detector.
Some other embodiments of the video processing apparatus comprise a first video processing module, a second video processing module, and an arbiter. The first video processing module executes a first video detection for a first video processing operation. The second video processing module is coupled to the first video processing module and executes a second video detection for second video processing operation. The arbiter is coupled to the first video processing module and the second video processing module and is utilized for determining a target detection result according to detection results of the first and second video processing modules. The first video processing module performs the first video processing operation with reference to the target detection result. In an embodiment, the second video processing module performs the second video processing operation with reference to the target detection result.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, electronic equipment manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms “include” and “comprise” are used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to . . . ”. Also, the term “couple” is intended to mean either an indirect or direct electrical connection. Accordingly, if one device is coupled to another device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.
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Similarly, taking motion detection as another example, de-interlace module 205 executes a line-based motion detection for de-interlacing the interlaced video signal Sin to generate the progressive video signal S′, and motion compensation module 210 utilizes or refers to the detection result of the line-based motion detection executed by de-interlace processing module 205. The detection result Sdet can comprise data such as information indicating the video signal Sin is a normal video signal/film mode video signal, information indicating the frame is a still/motion frame, information regarding motion directions, or any information that can be retrieved by de-interlace processing module and is useful for motion compensation module 210.
In some examples, instead of directly utilizing the detection result Sdet without executing video detection, the second video processing module 210 executes video detection with reference to the detection result Sdet received from the first video processing module 205 for the second video processing operation. For example, the second video processing module 210 references the detection result Sdet of the first video detection (e.g. the line-based video detection) to adjust a decision threshold of entering/exiting a film mode or to dynamically adjust a decision threshold for motion detection, for executing the second video detection (e.g. the block-based video detection). For instance, if the detection result Sdet indicates the interlaced video signal Sin changes into a film mode video signal from a normal video signal or the interlaced video signal Sin is a film mode video signal, the second video processing module 210 decreases the decision threshold of entering the film mode or increases the decision threshold of exiting the film mode when executing the second video detection, so as to enter or remain in film mode more easily. Otherwise, if the detection result Sdet indicates the interlaced video signal Sin changes into a normal video signal from a film mode video signal or the interlaced video signal Sin is a normal video signal, the second video processing module 210 decreases the decision threshold of exiting the film mode when executing the second video detection, so as to enter the normal mode more easily. Similarly, taking the motion detection as an example, if the detection result Sdet indicates the interlaced video signal Sin is a motion video signal, motion compensation module 210 decreases the decision threshold for motion detection when executing the block-based motion detection, so as to increase the probability that the progressive video signal S′ is identified as a motion video signal. Otherwise, if the detection result Sdet indicates the interlaced video signal Sin is a still video signal, the second video processing module 210 increases the decision threshold for motion detection when executing the block-based motion detection, so as to increase the probability that the progressive video signal S′ is identified as a still video signal. An advantage is that conflict situations where two modules came up with different detection results can be reduced, for example, in a case when one of the interlaced video signal Sin and progressive video signal S′ is identified as a film mode video signal while the other is identified as a normal video signal. The performance of the video processing apparatus 200 therefore becomes more reliable with greater noise robustness.
Additionally, in another embodiment, a first video processing module such as de-interlace processing module can also utilize a detection result of a second video processing module such as motion compensation module without executing all or a part of video detection, to perform de-interlace operation. Please refer to
Instead of directly utilizing the detection result Sdet′ without executing the second video detection (i.e. the line-based video detection), the second video processing module 305 can also execute the second video detection with reference to the detection result Sdet′ of the first video detection. Specifically, the second video processing module 305 references the detection result Sdet′ of the first video detection (i.e. the block-based video detection) to adjust a decision threshold of entering/exiting a film mode or to dynamically adjust a decision threshold for motion detection. For example, if the detection result Sdet′ determines the progressive video signal S′ changes into a film mode video signal from a normal video signal or the progressive video signal S′ is still a film mode video signal, the second video processing module 305 decreases the decision threshold of entering the film mode or increases the decision threshold of exiting the film mode when executing the second video detection, so as to enter or remain in film mode more easily. Otherwise, if the detection result Sdet′ determines the progressive video signal S′ changes into a normal video signal from a film mode video signal or the progressive video signal S′ is a normal video signal, the second video processing module 305 decreases the decision threshold of exiting the film mode when executing the second video detection, so as to enter the normal mode more easily.
Furthermore, in another embodiment, an arbiter (e.g. a central controller) can aid determining a target detection result according to detection results of a line-based video detection and a block-based video detection. Please refer to
Moreover, it should be noted that the de-interlace processing modules and motion compensation modules in the above embodiments are only for illustrative purposes. These are not meant to be limitations of the present invention. In other embodiments, a first/second video processing module can be a noise reduction module or a comb filter, etc. In other words, no matter what a particular video processing operation is de-interlace processing, motion judder compensation, noise reduction, or comb filtering, etc, performing the particular video processing operation by using/referencing a result of video detection for a different video processing operation obeys the spirit of the present invention.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.
