The present disclosure relates to the field of multi-media systems and, more particularly, to a method and computing device for performing virtual camera functions during playback of media content on a computing device.
The ability of cameras to capture higher definition and larger format videos is becoming a commodity. On the other hand, display devices are small, constrained by network speeds and constrained by computational capabilities. Viewing high-definition or panoramic video on small screen devices results in scaling down of the display region. This results in loss in perceptual detail.
One of the major issues in video playback is the mismatch between the screen dimensions and the video frame dimensions. Today, it is very easy to record a High Definition (HD), Panoramic and Ultra High Definition (UHD) video. In many cases, these videos are viewed on small-screen devices. As a result, detail in the recorded video is lost. For example, viewing a high resolution lecture video on a small screen-device would result in the tiny characters from slides and whiteboard. Traditionally, this problem has been addressed by providing features such as pinch-to-zoom. These features are not adequate when the object of interest is rapidly moving. Too many user interactions are required in order to keep the object of interest in focus there by defeating the purpose of pleasant viewing experience.
To address the above-discussed deficiencies, the present disclosure may provide a method and computing device for retargeting a viewport to screen dimensions by automatically zooming-in, zooming-out, and/or panning a selected region of interest (RoI) during the playback of video.
An embodiment in this disclosure may provide a method for performing a virtual camera function. The method comprises selecting a region of interest (RoI) during a playback of media content; representing the RoI as an ensemble of disparate hypotheses; identifying the RoI in a frame sequence sampled according to the hypotheses; performing a virtual camera action on the identified RoI; and playing the RoI with a virtual camera.
Another embodiment in this disclosure may provide a computing device for performing a virtual camera function. The computing device comprises a virtual camera control module configured to render media content, and a processor configured to select a region of interest (RoI) during a playback of media content, to represent the RoI as an ensemble of disparate hypotheses, to identify the RoI in a frame sequence sampled according to the hypotheses, to perform a virtual camera action on the identified RoI, and to play the RoI with a virtual camera.
Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.
For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a frame” includes reference to one or more of such frames.
The present disclosure provides a method and computing device for performing virtual camera functions during playback of media content on a computing device (e.g., a mobile phone, smart phone, tablet, phablet, interactive television, and the like).
Video players have evolved in complexity in order to cater to the varying display resolutions, display sizes, availability of touch and gesture-based interactions. High resolution video is increasingly being viewed on small screen devices. Capture devices are also becoming miniaturized yet are able to capture high resolution videos. Sharing of captured videos is common. Nevertheless, there are key challenges in being able to quickly search, share and bookmark high resolution/large format videos on hand-held devices. Not all parts of a high resolution video are important for a user especially if one wants to share/save regions of interest, objects of interest, and/or view regions-of-interest.
In order to help users interact and have a better experience with large format (e.g., High Definition) videos on small screen devices, a video player that performs virtual camera functions in a pre-recorded video is disclosed. The virtual camera automatically zooms-in/zooms-out/pans of a region of interest within the high resolution video, there by retargeting a viewport to screen dimensions. Objects of interest appear magnified and in focus. As a result, the detail that was lost because of the small screen size is circumvented. The virtual camera automatically determines when to zoom-in/out, and how much to zoom-in/out. The present disclosure is also capable of capturing the user intent for the object of interest (OoI), retarget the OoI at 30 fps, and pre-fetching frames to initiate time delayed processing.
For example, during a video playback, a region-of-interest (RoI) is selected by a user via a touch based gesture by encircling a region of interest. For example, a RoI in a pre-recorded video is selected during video playback via spot-zoom, pinch zoom, or S-pen (stylus pen). The computing device can detect a gesture for selecting a RoI during the playback of video. Upon detection of such a gesture, a video playback may be slowed down/temporarily paused to aid selection of a RoI when an object of interest is moving.
Exemplary RoIs selected by a user are shown in
Referring to
Alternatively, the RoI is automatically selected when the first time foreground motion is detected. In other embodiments, the RoI may be derived from an external source. The RoI can be of irregular size and shape as indicated by a reference number 607. The RoI may contain a specific object of interest (OoI). The OoI may move within a scene that has a fixed or a varying background or the OoI may be stationary in a scene. Sometimes, there may be many OoIs. The OoI may be a human, or a non-human entity or many such entities.
Upon selection of a RoI, the region is represented in a form over which computations can be performed as shown in
Referring to
Then, at operation 107, the computing device may detect edges from a value image among the hue, saturation, and value images. Also, at operation 109, the computing device may select hue and saturation pixels that are on every line joining the center of the RoI and the detected edge points, and then at operation 111, build a 2D histogram of pixel values. And also, at operation 113, the computing device may refer to the 2D histogram of pixel values built at operation 111 as the first RoI representation (RoI REP-1).
Meanwhile, at operation 115, the computing device may represent each pixel in the hue image, among images represented at operation 105, as a binary pattern (hash key) based on pixel differences in different directions. Further, at operation 117, the computing device may represent each pixel in the value image as a binary pattern (hash key) based on pixel differences in different directions. Then, at operation 119, the computing device may build a 2D histogram of hash keys by using pixels in the hue and value images. Also, at operation 121, the computing device may refer to the 2D histogram of hash keys built at operation 119 as the second RoI representation (RoI REP-2).
In one exemplary implementation, the selected RoI is represented as an ensemble of disparate hypothesis.
Referring to
Additionally, each rectangle may be converted into a representation through operations 209 to 219 shown in
At at operation 209, the computing device may select hue and saturation inside the rectangle and build a 2D histogram using the hue and saturation pixel values. At operation 211, the computing device may represent the 2D histogram representation as the first rectangular representation (REG REP-1).
Additionally, for each rectangle at operation 207, the computing device may select hue pixels inside the rectangle and represent them as a binary representation based on pixel differences in different directions at operation 213. Also, at operation 215, the computing device may select value pixels inside the rectangle and represent them as a binary pattern (hash key) based on pixel differences in different directions. Further, at operation 217, the computing device may build a 2D histogram using hash keys representing hue pixels and value pixels. At operation 219, the computing device may represent the 2D histogram representation built using the hash keys as the second rectangular representation (REG REP-2).
Referring to
In the sampled frame, the rectangle which best matches the original RoI may be determined. As shown in
Specifically, with regard to RoI REP-1 301, RoI REP-2 303, . . . , RoI REP-n 305, REG REP-1 307, REG REP-2 309, . . . , and REG REP-n 311, the computing device may perform at operation 313 a best match based on divergence measure through comparison between histogram bins and cross bins. Then the computing device may obtain coordinated REP-1 315, coordinated REP-2 317, . . . , and coordinated REP-n 319, and determine them as new viewports at operation 321. Also, the computing device may resize and reposition, at operation 323, the viewports on the basis of past history and object encapsulation metrics, and then transmit such viewport to virtual camera action at operation 325.
Additionally, the new RoI may be repositioned accounting for object coverage metrics and heuristics for complete inclusion of object within the new RoI.
Hereinafter, the above-mentioned operation 325 will be described in detail with reference to
The camera functionality runs as a separate thread and performs virtual camera panning, zoom on the video being played out by the player. The smooth panning functionality (in frame sampled domain) is implemented using trajectory estimation techniques. This method accounts for the fact that the delay in processing the frame may happen between the point of capture of a frame and the point of request for a future frame.
Specifically, referring to
The smooth camera zoom is implemented as described using method steps illustrated in
Referring to
It can be noted that, the entire process of selection of RoI, and virtual camera control on the RoI can be performed multiple times simultaneously on different RoIs. In case multiple regions-of-interest are selected, the multiple ROIs are displayed in split-screen or picture-in-picture or thumbnail view. For example, the screen is split into multiple portions based on number of RoIs. In one embodiment, based on the initial RoI selection size, different RoIs may be assigned different ratios of screen ownership. Alternatively, different RoIs may be assigned equal share of screen ownership.
A reference number 901 in
Similarly, a reference number 907 in
The computing device may include additional components not shown in
The processor 1020 may be configured to implement functionality and/or process instructions for execution within the computing device. The processor 1020 may be capable of processing instructions stored in the memory 1040 or instructions stored on the storage device 1030. The processor 1020 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuitry. Additionally, the functions attributed to the processor 1020, in this disclosure, may be embodied as software, firmware, hardware or any combination thereof.
The storage device 1030 may include one or more computer-readable storage media. Also, the storage device 1030 may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable memories (EEPROM). In addition, the storage device 1030 may, in some examples, be considered a non-transitory storage medium. The term “non-transitory” may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term “non-transitory” should not be interpreted to mean that the storage device is non-movable. In some examples, the storage device 1030 may be configured to store larger amounts of information than the memory 1040. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in RAM or cache).
The memory 1040 may be configured to store information within the computing device during operation. The memory 1040 may, in some examples, be described as a computer-readable storage medium. The memory 1040 may be described as a volatile memory, meaning that the memory does not maintain stored contents when the computer is turned off. Examples of volatile memories include random access memories (RAM), dynamic random access memories (DRAM), static random access memories (SRAM), and other forms of volatile memories known in the art. In some examples, the memory 1040 may be used to store program instructions for execution by processor 1020.
The computing device may utilize the network interface 1050 to communicate with external devices via one or more networks, such as one or more wireless networks. The network interface 1050 may be a network interface card, such as an Ethernet card, an optical transceiver, a radio frequency transceiver, or any other type of device that can send and receive information. Examples of such network interfaces 1050 may include Bluetooth®, 3G and WiFi® radios in mobile computing devices as well as USB. Examples of such wireless networks may include WiFi®, Bluetooth®, and 3G. In some examples, the computing device may utilize the network interface 1050 to wirelessly communicate with an external device (not shown) such as a server, mobile phone, or other networked computing device.
The user interface (“UI”) 1060 allows a user of the computing device to interact with computing device. The UI 1060 may generate a graphical user interface (“GUI”) that allows a user to initiate commands. For example, according to some aspects of the disclosure, the UI 1060 generates a GUI that is displayed on a touch sensitive screen (“touch screen”) 1070. The GUI may include one or more touch sensitive UI elements. For example, a user may be able to interact with the computing device and initiate a command by touching one or more of the touch sensitive UI elements displayed on touch sensitive screen 1070.
The touch sensitive screen 1070 may include a variety of display devices such as a liquid crystal display (LCD), an e-ink display, a cathode ray tube (CRT), a plasma display, an organic light emitting diode (OLED) display, or another type of display device.
According to some aspects of the disclosure, the video player 1080 may play a pre-recorded video on the user interface 1060 of the computing device. The virtual camera control module 1090 may be configured for performing one or more method steps illustrated in
Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.
Number | Date | Country | Kind |
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200/CHE/2013 | Jan 2013 | IN | national |
The present application is related to and claims the benefit under 35 U.S.C. §119(a) of an Indian patent application filed on Jan. 15, 2013 in the Indian Patent Office and assigned Serial No. 200/CHE/2013, the entire disclosure of which is hereby incorporated by reference.