Patent Application
20120127288
1. Field of the Invention
The present invention generally relates to delay compensation system, and more particularly to a 2D-to-3D delay compensation system and method thereof.
2. Description of Related Art
Formerly the video displayed in a panel display device such as liquid crystal display (LCD) TV is two-dimensional (2D) image source. In the wake of developments in displaying technology, the applications of displaying three-dimensional (3D) visual effect have increased with each passing day, such as 3D films, 3D games, and product displaying, etc. It results that the 3D imaging system becomes more practical and popular.
Besides using 3D display to achieve 3D imaging effect, the displays with general functions can be connected with a 2-to-3D conversion box to generate 3D visual effect as well. Please refer to
The pair of shutter glasses 15 comprises a left (L) lens 151 and a right (R) lens 153. When the 2D-to-3D conversion box 13 outputs the left and right images, it may send out a synchronization signal to the pair of shutter glasses 15 for it to switch on and off its right and left lens 153, 151, which further controls the left and right images to only pass through the left and right lenses 151, 153 respectively. Therefore, when the viewer wears the pair of shutter glasses 15 to view the left and right images displayed by the display device 11, the 3D visual effect would be generated owing to binocular disparity between the left image and the right image.
However, before displaying the converted left and right images which is sent to the display device 11, the video content would be performed various image processing by the image processor 111 embedded in the display device 11. It will introduce a finite delay which is usually caused by the video processing delay of the display device 11. The introduction of this delay causes out-of-sync between the switch-on and switch-off of the pair of shutter glasses 15 and the display device's 11 playback of the right and left images. As a result, the viewer's 3D impression will be adversely impacted.
For the reason that conventional 2D-to-3D imaging system could not effectively display 3D image or video owing to the video processing delay, a need has arisen to propose a novel delay compensation system and method to compensate the video processing delay and improve 3D visual effect.
In view of the foregoing, it is an object of the embodiment of the present invention to provide a 2D-to-3D delay compensation system and method thereof to compensate the video processing delay caused by the display device to perform image processing for the right and left images.
According to one embodiment, a 2D-to-3D delay compensation system tied in with a display device comprises a 2D-to-3D conversion box and a pair of shutter glasses. The 2D-to-3D conversion box is coupled with the display device and sends out at least a calibration pattern to the display device to display. When sending each calibration pattern, the 2D-to-3D conversion box sends out a shutter control signal after waiting a delay time. The pair of shutter glasses which comprises a left (L) lens and a right (R) lens receives the shutter control signal to switch on and off its left and right lenses. The pair of shutter glasses further comprises a detection unit which is configured to detect the calibration pattern and then send out an adjustment signal to the 2D-to-3D conversion box. Wherein, when the calibration pattern detected by the detection unit is substantially complete, the detection unit will send out a synchronization signal to the 2D-to-3D conversion box. The 2D-to-3D conversion box adaptively adjusts the delay time after receiving the adjustment signal until the synchronization signal is received.
According to another embodiment, a 2D-to-3D delay compensation method for making a pair of shutter glasses be synchronization with a display device's playback of a video source is disclosed. The display device is coupled with a 2D-to-3D conversion box. The method includes the following steps: firstly, the 2D-to-3D conversion box sends out a calibration pattern to the display device. Then, a shutter control signal is sent out after waiting a delay time to switch on and off the pair of shutter glasses' left and right lenses. Subsequently, the calibration pattern is detected. Finally, determine whether the delay time must be adjusted or not according to the detecting result. Accordingly, the shutter control signal may be sent out after waiting the adjusted delay time to adaptively switch on and off its lenses to be synchronization with the video source.
The pair of shutter glasses 25 comprises a left (L) lens 251 and a right (R) lens 253. When the 2D-to-3D conversion box 23 outputs the left and right images, it may send out a shutter control signal to the pair of shutter glasses 25 for the pair of shutter glasses 25 to switch on and off its right and left lens 253, 251, which further controls the left and right images to only pass through the left and right lenses, 251 and 253, respectively. For example, the 2D-to-3D conversion box 23 converts the input 2D video source, e.g. 60 Hz progressive, to a converted 3D output format, e.g. 120 Hz with left and right-eye frame each 60 Hz in the shutter glasses application.
The display device 21 comprises an image processor 211 which is configured to perform various image processing, such as luminance, color or contrast adjustment, for the converted left and right images, and then displays the processed left and right images to be received by the left and right lenses, 251 and 253, respectively. In one embodiment, the display device 21 may be, but is not limited to, a Plasma Display Panel (PDP), Plasma TV, Liquid Crystal Display (LCD) TV, or Cathode Ray Tube (CRT) TV.
The 2D-to-3D conversion box 23 pre-stores tailor-made special calibration patterns, in one embodiment, the calibration pattern can be, but is not limited to, a completely black pattern, for example, a completely black frame, or a completely white pattern, for example, a completely white frame. Before converting the 2D video source, the 2D-to-3D conversion box 23 sends out the calibration pattern to the display device 21, and estimates the time that the pair of shutter glasses 25 receives the processed calibration pattern from the image processor 211 to control the lenses to adaptively switch on and off to be synchronization with the calibration pattern.
The pair of shutter glasses 25 further comprises a detection unit 3 which is configured to detect the calibration pattern.
Take that the calibration pattern is a completely black pattern and the detection unit 3 is installed behind the right lens 253 as example, when the 2D-to-3D conversion box 23 transmits the completely black calibration pattern to the display device 21, the shutter control signal is sent out after waiting a delay time to switch off the shutter glasses' left lens. After the delay time, the completely black calibration pattern processed by the image processor 211 only passes through the right lens 253. The photo-sensitive resistor R2 in the right lens 253 determines the voltage-divided value Vd according to the brightness of the calibration pattern detected. If the right lens 253 receives a complete black frame, the resistance value of the photo-sensitive resistor R2 should become large to make the output of the voltage divider circuit 31 (e.g. voltage-divided value Vd) reach its maximum, e.g. Vcc. Then the comparator 33 compares the voltage-divided value Vd with the threshold TH. In the present embodiment, if the voltage-divided value Vd is larger than the threshold TH, it indicates that the right lens 253 receives a completely or substantially completely black calibration pattern, the pair of shutter glasses 25 will send out a synchronization signal to the 2D-to-3D conversion box 23. In this case, the present delay time just equals or substantially equals the time that the image processor 211 processes the calibration pattern to make the right lens 253 receive the calibration pattern synchronously.
On the contrary, if the voltage-divided value Vd is less than the threshold TH, it indicates that the time of processing the calibration pattern by the image processor 211 may be less or more than the delay time set, the pair of shutter glasses 25 will output a adjustment signal to the 2D-to-3D conversion box 23 due to the reason that it cannot receive the completely black calibration pattern exactly. The 2D-to-3D conversion box 23 adaptively adjusts the delay time after receiving the adjustment signal until the synchronization signal is received.
Similarly, the calibration pattern can be a completely white pattern, the detection unit 3 can be installed behind the left lens 251, and the photo-sensitive resistor R2 can be set in the position of resistor R1. The operation rule of the comparator 33 can be adaptively set in accordance with the circuit design. For example, if the voltage-divided value Vd is less than the threshold TH, the synchronization signal is outputted, or the adjustment signal is outputted. In one specific embodiment, the 2D-to-3D conversion box 23 sends out continuous but separated completely black patterns and completely white patterns. When sending each calibration pattern, the shutter control signal is sent out after waiting the delay time to switch on and off the left and right lenses 251, 253 until the synchronization signal is received. It indicates that the above case is completely black for the left-eye frame and completely white for the right-eye frame synchronously, respectively.
Please refer to
When first-time use of this setup or every time a new display device is used, the 2D-to-3D delay compensation system 2 needs to be initialized with a calibration phase to ensure quality 3D viewing experience. Firstly, in step S401, the 2D-to-3D conversion box 23 sends out the pre-stored calibration pattern to the display device 21, and the shutter control signal is sent out after waiting the default delay time to switch on and off the left and right lenses 251, 253 of the pair of shutter glasses 25 in step S403. After receiving the calibration pattern, the display device 21 performs image processing for it to display in step S405.
Sequentially, in step S407, the detection unit 3 configured behind the right lens 253 detects the calibration pattern processed by the display device 21. The voltage-divided value Vd is then generated according to the brightness of the calibration pattern. In step S409, whether the voltage-divided value Vd is larger than the default threshold TH is determined. If yes, it indicates that the time that the image processor 211 performs image processing equals or substantially equals the present delay time, and make the right lens 253 receive a completely black calibration pattern to achieve synchronization. Therefore, in step S411, the pair of shutter glasses 25 sends out the synchronization signal to the 2D-to-3D conversion box 23.
If the voltage-divided value Vd is not larger than the default threshold TH, it indicates that the right lens 253 is switched on, which is controlled by the shutter control signal too early or too late, the processed calibration pattern cannot pass through the right lens 253 synchronously. Therefore, in step S413, the pair of shutter glasses 25 sends out the adjustment signal to the 2D-to-3D conversion box 23 to adjust the delay time. The 2D-to-3D conversion box 23 adaptively adjusts the delay time and repeats the step S401-S409 after receiving the adjustment signal until the synchronization signal is received.
In a specific embodiment of the present invention, the calibration pattern is sent out periodically and separately in the step S401, for example, a completely white calibration pattern follows a completely black calibration pattern, and so on. The calibration pattern is outputted continuously, and the switch-on and switch-off of the left and right lenses 251, 253 should be in synchronization with the display device's 21 playback of the completely white calibration pattern and the completely black calibration pattern respectively.
After finishing the above initialized process, the viewer can wear the pair of shutter glasses 25 and input the 2D video source to the 2D-to-3D conversion box 23 to convert it into continuous right images and left images in step S415. Then, the 2D-to-3D conversion box 23 outputs the right and left images separately to the display device 21 in step S417 and sends the shutter control signal with the adjusted delay time in step S419. That is, when transmitting each image (right or left image), the shutter control signal is sent out after waiting the delay time which can compensate image processing delay. Therefore, the left and right lenses 251, 253 can be controlled to receive the completely right and left images by time-division to achieve synchronization.
Although specific embodiments have been illustrated and described, it will be appreciated by those skilled in the art that various modifications may be made without departing from the scope of the present invention, which is intended to be limited solely by the appended claims.
