JP2012114544A - Video encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption without substantially deteriorating reproduction quality and image quality and to reduce memory capacity and a load of a communication line.SOLUTION: An encoding rate control portion 19 creates an image quality control signal for dropping only an encoding rate of a user's eye with a poor eyesight or an eye of a non-dominant eye and supplies it to an encoding portion 14. A control portion for the number of encoding pixels 20 creates an image quality control signal for dropping only the number of encoding pixels of the user's eye with the poor eyesight or the eye of the non-dominant eye and supplies it to the encoding portion 14. A left eye encoding portion 15L and a right eye encoding portion 15R in the encoding portion 14 encode the relatively low encoding rate or the relatively small number of encoding pixels in the encoding portion corresponding to the eye of the poor eyesight or the eye of the non-dominant eye compared to the encoding portion corresponding to the other eye based on the image quality control signal.

Description

  The present invention relates to a video encoding device, and more particularly to a video encoding device that encodes a right-eye video signal and a left-eye video signal that constitute a stereoscopic video signal.

  Various techniques have been proposed for stereoscopic video technology. First, with regard to display, there are methods such as using a polarizing eye mirror, using a liquid crystal shutter eye mirror, and arranging a lenticular plate in front of the display screen so that the right eye and left eye see the right eye image and left eye image, respectively. It is considered.

  For stereoscopic display, normally, two video signals, a right-eye video signal and a left-eye video signal, are required. When the at least two video signals are broadcast, transmitted, or recorded on a recording medium, this signal data amount becomes a problem. Therefore, a technique for compressing and decoding two video signals of a right-eye video signal and a left-eye video signal for broadcasting or recording has been proposed (for example, see Patent Document 1).

JP 54-30717 A

  However, in the conventional video encoding device such as the stereoscopic image display device described in Patent Document 1, the processing ability of each picture that enters from the left and right eyes differs depending on the visual ability such as the dominant eye and visual acuity of human eyes. Therefore, in some cases, even when detailed information is not so necessary, since the two video signals of the right-eye video signal and the left-eye video signal are always encoded in the same manner, power consumption is relatively large. Further, since the amount of signal compression is not sufficient, there is a problem that the load on a large capacity memory and communication line is large.

  The present invention has been made in view of the above points, and provides a video encoding apparatus capable of reducing power consumption without substantially reducing reproduction quality and image quality, and reducing memory capacity and communication line load. The purpose is to provide.

  To achieve the above object, the present invention provides a left-eye encoding means for encoding a left-eye video signal based on an image quality control signal, and a right-eye code for encoding a right-eye video signal based on an image quality control signal. Visual information discriminating means for discriminating superiority or inferiority of the right eye and the left eye from the user's visual acuity information or dominant eye information, and the eye having the poor visual acuity determined by the visual information discriminating means, or the dominant eye The coding rate or the number of coded pixels of the left-eye coding means or right-eye coding means corresponding to the non-eye is encoded by the right-eye coding means or left-eye coding means corresponding to the other eye. And image quality control means for controlling the left-eye encoding unit or the right-eye encoding unit so as to be lower than the rate or the number of encoded pixels.

  According to the present invention, power consumption can be reduced without substantially reducing reproduction quality and image quality, and memory capacity and communication line load can be reduced.

It is a block diagram of one embodiment of a video encoding device of the present invention. It is a flowchart explaining the image quality control method in one Embodiment of the video coding apparatus of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a block diagram of an embodiment of a video encoding apparatus according to the present invention. In the figure, a video encoding device 10 of the present embodiment includes a left-eye lens 11L, a left-eye image sensor 12L, a left-eye image buffer 13L, a right-eye lens 11R, a right-eye image sensor 12R, a right-eye image buffer 13R, The encoder 14 and the multiplexer 21 are included.

  The left-eye side optical system including the left-eye lens 11L and the left-eye image pickup device 12L and the right-eye side optical system including the right-eye lens 11R and the right-eye image pickup device 12R are paired and separated from each other by about the distance between the human eyes. Arranged to shoot 3D video. As is well known, a three-dimensional image can be formed from two images, a right-eye image and a left-eye image having a parallax in the horizontal direction, so that the left-eye image sensor 12L and the right-eye image sensor 12R. Thus, a three-dimensional image can be obtained.

  In the left-eye imaging element 12L, light from a subject (not shown) is imaged on the imaging surface by the left-eye lens 11L, and the light is photoelectrically converted to generate a left-eye video signal in the left-eye image buffer 13L. Supply. On the other hand, at the same time, the right-eye imaging element 12R forms light on the imaging surface with light from a subject (not shown) by the right-eye lens 11R, and photoelectrically converts the light to generate a right-eye video signal. This is supplied to the right-eye image buffer 13R.

  The left-eye image buffer 13L temporarily stores the input left-eye video signal and then supplies the left-eye video signal to the left-eye encoding unit 15L in the encoding unit 14. On the other hand, the right-eye image buffer 13R temporarily stores the input right-eye video signal, and then supplies it to the right-eye encoding unit 15R in the encoding unit 14. The left-eye video signal output from the left-eye image buffer 13L and the right-eye video signal output from the right-eye image buffer 13R are synchronized with each other.

  The video encoding device 10 includes a visual information acquisition unit 16, a visual information input unit 17, and an image quality control unit 18. The visual information acquisition unit 16 acquires visual information including the user's eyesight information and dominant eye information. The visual information input unit 17 determines whether the visual acuity of the user's right eye or left eye is better or the same from the visual information, supplies the visual acuity determination information to the image quality control unit 18, and the dominant eye information. Then, the user's dominant eye is determined and the dominant eye determination information is supplied to the image quality control unit 18. The visual information acquisition unit 16 and the visual information input unit 17 constitute the visual information determination unit of the present invention that determines the superiority or inferiority of the right eye and the left eye from the user's eyesight information and dominant eye information.

  The image quality control unit 18 includes an encoding rate control unit 19 and an encoded pixel number control unit 20, and based on visual acuity determination information and dominant eye determination information input by one of the selected control units. Then, an image quality control signal indicating the image quality determined by controlling the encoding rate or the number of pixels is output.

  When encoding the left-eye video signal and the right-eye video signal based on a predetermined encoding method, the left-eye encoding unit 15L and the right-eye encoding unit 15R in the encoding unit 14 are supplied from the image quality control unit 18. Are encoded with the image quality set by the image quality control signal. The multiplexing unit 21 multiplexes the left-eye video stream and the right-eye video stream obtained by encoding by the left-eye encoding unit 15L and the right-eye encoding unit 15R, respectively, and generates one bit stream. Output.

  Next, the image quality determination method in the video encoding apparatus 10 of the present embodiment in FIG. 1 will be described in detail with reference to the flowchart in FIG.

  First, an encoding rate to be recorded is set (step S1). This encoding rate is the encoding rate of the bit stream output from the multiplexing unit 21. Subsequently, the visual information acquisition unit 16 acquires visual information composed of the user's eyesight information and dominant eye information (step S2). A method for acquiring visual acuity information is known (for example, see JP-A-2004-337546), and a method for acquiring dominant eye information is also known (for example, see JP-A-2009-47912). Since the information acquisition method itself is not important in the present invention, its detailed description is omitted.

  Subsequently, the visual information input unit 17 determines whether the visual acuity of the right eye or the left eye is good or the same from the input visual acuity information (step S3). Further, when the visual acuity of the right eye and the visual acuity of the left eye are the same, the visual information input unit 17 determines whether the dominant eye is the right eye or the left eye from the input dominant eye information (step S4). The visual information input unit 17 supplies the determination result determined in steps S3 and S4 to the image quality control unit 18. In this way, visual acuity is given priority over dominant eyes because of the characteristics of human eyes. Therefore, when the information that the dominant eye is either and the information that the visual acuity is either different, the image quality is controlled with priority on the visual acuity.

  The image quality control unit 18 selects either one of the change of the encoding rate by the encoding rate control unit 19 and the change of the number of encoded pixels by the encoded pixel number control unit 20, and the selected change method. The image quality control signal determined in step 1 is generated.

  Therefore, first, assuming that the encoding rate change by the encoding rate control unit 19 is selected, the encoding rate control unit 19 has a better visual acuity for the right eye than for the left eye. If the right eyesight and left eyesight are the same, and the input dominant eye determination information indicates that the right eye is dominant, the coding rate of the left eye is reduced. A rate is calculated (steps S5 and S7), and only the coding rate of the left eye is lowered based on the coding rate reduction rate (step S8).

  The coding rate control unit 19 also indicates that the input visual acuity determination information indicates that the left eye has better visual acuity than the right eye, or the right eye acuity and the left eye acuity are the same, and the input If the dominant eye determination information indicates that the left eye is the dominant eye, the right eye coding rate reduction rate is calculated (steps S6 and S11), and the right eye code is calculated based on the coding rate reduction rate. Only the conversion rate is lowered (step S12). The reduction rate of the encoding rate is proportional to the difference in visual acuity, and the reduction rate of the encoding rate increases as the difference increases. Similarly, for the dominant eye, the rate of decrease in the coding rate can be increased as the difference in the dominant eye becomes extreme.

  On the other hand, assuming that the change of the number of encoded pixels by the encoded pixel number control unit 20 is selected, the encoded pixel number control unit 20 indicates that the input visual acuity determination information has a visual acuity of the right eye than that of the left eye. If the right eye sight and the left eye sight are the same, and the input dominant eye determination information indicates that the right eye is dominant, the coded pixel of the left eye The number reduction rate is calculated (steps S5 and S9), and only the number of encoded pixels of the left eye is reduced based on the encoded pixel number reduction rate (step S10).

  In addition, the encoded pixel number control unit 20 indicates that the input visual acuity determination information indicates that the left eye has better visual acuity than the right eye, or the visual acuity of the right eye and the visual acuity of the left eye are the same, and If the input dominant eye determination information indicates that the left eye is the dominant eye, the right pixel coding pixel number reduction rate is calculated (steps S6 and S13), and based on the coding pixel number reduction rate. Only the number of pixels for the right eye is lowered (step S14). The number of encoded pixels is proportional to the difference in visual acuity, and the decrease rate of the number of encoded pixels increases as the difference increases. Similarly, for the dominant eye, the rate of decrease in the number of encoded pixels can be increased as the difference between the dominant eyes becomes extreme. For example, one may be the number of high definition (HD) encoded pixels, and the other may be the number of standard (SD) encoded pixels.

  In this way, the image quality control unit 18 determines the coding rate or the number of coded pixels of the eye with the poor eyesight or the non-dominant eye determined in any of steps S8, S10, S12, and S14. Is generated relative to the encoding rate or the number of encoded pixels of the other eye, and is supplied to the encoding unit 14.

  Based on the image quality control signal, the left-eye encoding unit 15L and the right-eye encoding unit 15R in the encoding unit 14 are encoding units corresponding to eyes with poor vision or non-dominant eyes. Compared with the encoding unit corresponding to the other eye, encoding is performed at a relatively low encoding rate or the number of small encoding pixels.

  As described above, according to the video encoding device 10 of the present embodiment, the human eyes have different processing abilities of the pictures coming from the left and right eyes depending on visual abilities such as dominant eyes and visual acuity. It is possible to significantly reduce the amount of encoded stream data corresponding to the eye with poor vision or the non-dominant eye compared to the amount of encoded stream data corresponding to the other eye. As a result, the data amount of one entire bit stream output from the multiplexing unit 21 can be greatly reduced, so that power consumption can be reduced compared to the conventional case, and the memory capacity can be reduced and the communication line load can be reduced. Can be reduced. The video encoding apparatus 10 according to the present embodiment is particularly effective when a user to be viewed is specified when video information is recorded and played back by a mobile device such as a mobile phone, or when personal use is used.

  According to the present embodiment, the image quality corresponding to the eye with poor vision or the non-dominant eye is significantly lower than the image quality of the other image, but the image quality is lowered by the user. Since the image of the one that has been viewed is viewed with the eye with the poor eyesight or with the eye that is not dominant, the reproduction image quality is hardly noticed by the user. Therefore, according to the video encoding device 10 of the present embodiment, the amount of code signal can be reduced without substantially reducing the reproduction quality and image quality.

  According to an experiment by the present inventor, when the encoding rate is set to 30 Mbps and the human eye has a right eyesight of 1.0 and a left eyesight of 0.2, the left eye encoding rate can be reduced to 10 Mbps. It was possible. In the above case, even if the coding rate on the left eye side is reduced by about 70%, the video on the right eye side is dominant, so that the difference in coding rate cannot be recognized. In this case, it was found that higher quality video can be seen than when the left and right average encoding rates are lowered.

  The present invention is not limited to the above-described embodiment. For example, the right-eye image signal and the left-eye video signal may be input from a recording medium or the like. Alternatively, the visual information input by the visual information input unit 17 may be used without using the visual information acquisition unit 16.

11L Left-eye lens 11R Right-eye lens 12L Left-eye imaging device 12R Right-eye imaging device 13L Left-eye image buffer 13R Right-eye image buffer 14 Encoding unit 15L Left-eye encoding unit 15R Right-eye encoding unit 16 Visual information acquisition unit 17 Visual information input unit 18 Image quality control unit 19 Encoding rate control unit 20 Encoded pixel number control unit 21 Multiplexing unit

Claims (1)

A left-eye encoding means for encoding the left-eye video signal based on the image quality control signal;
A right-eye encoding means for encoding a right-eye video signal based on the image quality control signal;
Visual information discrimination means for discriminating between superiority or dominant eyesight of the right eye and the left eye from the user's eyesight information or dominant eye information;
The encoding rate or the number of encoded pixels of the left-eye encoding means or the right-eye encoding means corresponding to the eye with the poor visual acuity determined by the visual information determination means or the non-dominant eye, Control the left-eye encoding unit or the right-eye encoding unit so as to lower the encoding rate or the number of encoded pixels of the right-eye encoding unit or the left-eye encoding unit corresponding to the other eye. An image quality control means.

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