Error detecting and correcting structured light patterns

Techniques are disclosed for detecting image depth in three-dimensional (3-D) surface imaging. The disclosed techniques can be used, for example, to provide structured light encoded with a coded word that includes error-correcting code (ECC). The ECC is effectively configured to detect and correct data errors as may result, for example, from the presence of ambient light and/or camera-noise-causing errors during imaging. In an example case, the coded word is a 15-bit pattern provided in a 3×5 matrix and including: (1) nine data bits of disparity code; (2) five ECC bits for correcting an error and detecting two errors; and (3) one 8-bit/10-bit encoding bit to ensure the presence of a transient pixel in the data for white threshold level detection. Greater or lesser bit quantities and varied bit partitioning matrices can be provided, as desired. In some cases, imaging robustness and/or power usage can be improved using the disclosed techniques.

BACKGROUND

Three-dimensional (3-D) surface imaging involves a number of non-trivial challenges and has faced particular complications with respect to acquiring depth information pertaining to objects being imaged.

DETAILED DESCRIPTION

Techniques are disclosed for detecting image depth in three-dimensional (3-D) surface imaging. The disclosed techniques can be used, for example, to provide structured light encoded with a coded word that includes error-correcting code (ECC). The ECC is effectively configured to detect and correct data errors as may result, for example, from the presence of ambient light and/or camera-noise-causing errors during imaging. In an example case, the coded word can be a 15-bit pattern provided in a 3×5 matrix and including: (1) nine data bits of disparity code; (2) five ECC bits for correcting an error and detecting two errors; and (3) one 8-bit/10-bit encoding bit to help ensure the presence of a transient pixel in the data for white threshold level detection. Greater or lesser bit quantities and varied bit partitioning matrices can be provided, as desired. In some cases, imaging robustness can be improved using the disclosed techniques. Also, in some instances, the quantity of errors detected can be used, for example, to tune the output power of the light source utilized during imaging, in some cases reducing the output power until a desired error threshold is reached. Numerous configurations and variations will be apparent in light of this disclosure.

General Overview

As previously indicated, there are a number of non-trivial issues that can arise which can complicate three-dimensional (3-D) surface imaging. For instance, one non-trivial issue pertains to the ability to acquire depth information pertaining to an object. To do so, 3-D cameras can employ structured light and coded light. However, in the case of a structured light process, it is difficult to efficiently encode the disparity code in the patterns of the static projected slide utilized in such a process. Also, existing structured light systems utilize very large slide patterns, which result in poor resolution a id are not immune to noise and thus require use of very high powered lasers and provision of a dark environment. Furthermore, existing structured light systems have issues with undetected, noisy, and/or faulty pixels and suffer from depth-reading errors. Increasing the power of the laser or the size of the patterns in an attempt to mitigate these complications negatively impacts the resolution. Also, using a coded light process which uses time multiplexing to encode the pattern in a small space in an attempt to regain this lost resolution increases system complexity and is poorly suited for detecting moving objects. In any case, these existing systems are very complicated to calibrate, and most algorithms employed in these approaches require running a calibration process before using the system.

Thus, and in accordance with an embodiment of the present disclosure, techniques are disclosed for providing structured light encoded with a coded word including error-correcting code (ECC) and which is capable of detecting and correcting errors. In some embodiments, the structured light can be encoded, for example, with a 15-bit pattern provided in a 3×5 matrix including: (1) nine data bits; (2) five ECC bits; and (3) one 8-bit/10-bit encoding bit. In some such cases, the nine data bits can be a disparity code, the five ECC bits can be used to correct an error and to detect two errors, and the 8-bit/10-bit encoding bit can help to ensure the presence of a transient pixel in the data for white threshold level detection. Greater or lesser bit quantities and varied matrices (e.g., 4×4; 4×5; 5×5; etc.) can be provided, as desired, in accordance with other embodiments. It may be desirable in some cases to provide additional ECC bits for matrices larger than 3×5, for example, for additional robustness.

The techniques disclosed herein can be used, for example, for sub-pixel position calculations, automatic brightness calibration, and/or pixel alignment, in accordance with some embodiments. Furthermore, and in accordance with an embodiment, the use of ECC in the structured light can be utilized, for example, for managing the output power of the light source (e.g., a laser) which emits the light to be encoded with a coded word. That is, in some cases, the output power can be minimized or otherwise reduced, for example, to conserve power, by decreasing the output power of the light source until the errors are no longer correctable. Thus, in this sense, the quantity of errors detected can be used, for example, to tune the output power of the light source utilized during imaging, in some cases reducing the output power until a desired error threshold is reached.

Some embodiments can be used, for example, with 3-D imaging devices (e.g., cameras, video cameras, etc.), which, in some cases, may be utilized in any of a wide variety of computing devices, such as: a laptop/notebook computer; a tablet computer; a mobile phone or smartphone; a personal digital assistant (PDA); a cellular handset; a handheld gaming device; a gaming platform; a desktop computer; a smart television; and/or a videoconferencing system. Some embodiments can be used, for example, in: (1) 3-D vision applications, such as machine vision (MV) and other imaging-based automatic inspection and analysis; (2) depth cameras; (3) gesture recognition; and/or (4) gaming. Numerous suitable uses and applications will be apparent in light of this disclosure.

Some embodiments may realize advantages or benefits, for example, as compared to existing approaches. For instance, some embodiments may exhibit increased resistance to degradation of performance, for example, as otherwise might result from a noisy/hostile environment. Some embodiments may realize an increase in the quality of the depth of picture of a 3-D camera. Some embodiments may realize a reduction in power, for example, as compared to existing designs and may be implemented to reduce the power requirements of a host 3-D camera, which in turn may allow such a 3-D camera to be used in smaller or otherwise more power-sensitive platforms (e.g., smaller mobile computing devices). Some embodiments may realize a reduction in cost, for example, as compared to existing designs (e.g., such as by permitting use of optical sensors with less than optimal pixel performance or with a greater quantity of defective pixels). Also, and in accordance with an embodiment, use of the disclosed techniques may be detected, for example, by testing if a small spot of light (e.g., noise) is causing errors in the depth map or if it is robust to noise. As will be further appreciated, various embodiments can be implemented, for example, in software, firmware, hardware, and/or combination thereof.

Methodology and Operation

FIG. 1illustrates a three-dimensional (3-D) imaging system100configured in accordance with an embodiment of the present disclosure, andFIG. 2illustrates an example use of that system100. As can be seen, system100includes a light source1, which can be a projector or any other light source suitable for use in 3-D surface imaging, as will be apparent in light of this disclosure. The light emitted by light source1can be passed through a coded pattern mask2to produce structured light, which in turn can be used to provide structured-light illumination of a scene within the field of illumination of light source1. In accordance with some embodiments, mask2can be patterned with a code, such as coded word7(discussed below), for use in 3-D surface imaging. In some instances, mask2may be engraved with coded word7(e.g., mask2may be provided with a static pattern which represents coded word7). In any case, the patterned mask2(e.g., patterned with coded word7) can be reflected to an imaging screen8of an imaging input device3. Imaging input device3can be, for example, a still camera, a video camera, or any other imaging device suitable for use in 3-D surface imaging, as will be apparent in light of this disclosure. In some cases, imaging input device3may include components such as, but not limited to, an optics assembly, an image sensor, and an image/video encoder. However, the present disclosure is not so limited, as in some other cases, imaging input device3may be only an imaging sensor/optics (e.g., it need not be an entire camera/video camera). Numerous suitable configurations will be apparent in light of this disclosure.

As can further be seen, system100can include a processing unit4. In some embodiments, processing unit4can be separate from other components of system100, while in some other embodiments, processing unit4can be incorporated into or otherwise integrated with another portion of system100(e.g., with imaging input device3, with light source1, etc.). In any case, processing unit4can be configured to receive data from and/or transmit data to one or more other portions of system100or portions external to system100. To that end, and in accordance with some embodiments, processing unit4can be configured for wired (e.g., Universal Serial Bus or USB; Ethernet; FireWire; mobile industry processor interface, or MIPI; etc.) and/or wireless (e.g., Wi-Fi®; Bluetooth®; etc.) communications, for example, with light source1and/or imaging input device3. As such, it may be desirable to ensure that light source1and/or imaging input device3also are suitably configured for the desired type(s) of communications with processing unit4.

As will be appreciated, the reflected position of mask2(e.g., patterned with coded word7) as detected by imaging input device3at imaging screen8is based on triangulation. If the structured light (e.g., as provided by light source1in conjunction with coded word7) is incident with a non-planar surface of an object within the field of illumination of light source1, the geometric shape of that surface serves to distort the projected structured-light pattern as observed by imaging input device3. This distortion conveys information about the incident surface, which in turn can be used, in accordance with an embodiment, to determine the 3-D surface shape of the object in the scene. If the structured-light pattern is returned from an object which is near (e.g., near-field object5) or far (e.g., far-field object6), then it is detected by imaging input device in different locations9and10, respectively, on imaging screen8. Using known triangulation techniques, the distance can be calculated by the amount of shift (disparity) of the reflected pattern from the expected position to the actual position.

Thus, and in accordance with an embodiment, processing unit4can be configured to process such information as gathered by imaging input device3, for example, to extract the 3-D surface shape of a given object (e.g., near-field object5; far-field object6) within the field of illumination of light source1and mask2(e.g., which may be patterned with coded word7, discussed below). Processing unit4also may be configured to output the processed data for downstream use (e.g., by a portion external to system100).

As previously noted, and in accordance with some embodiments, mask2can be patterned with a coded word7to provide structured-light illumination of a scene within the field of illumination of light source1.FIG. 3illustrates an example 15-bit coded word7arranged in a 3×5 matrix, in accordance with an embodiment of the present disclosure. As can be seen, coded word7is made up of three rows with five bits each. In accordance with an embodiment, the first ten bits of coded word7are an 8-bit/10-bit representation of the 8-bit disparity, that is, the 8-bit binary word ‘00000000’ is converted to the 10-bit binary word11‘1001110100.’ Furthermore, and in accordance with an embodiment, the last five bits12of the coded word7represent five bits of error-correcting code (ECC), which, in some example cases, can be one of the Hamming codes. In any case, the first ten bits11may not be ‘00000’ or ‘11111,’ as will be appreciated. Thus, the ECC bits12may have at least one transition and therefore do not require an additional 4-bit/5-bit encoding, in accordance with an embodiment.

As will be farther appreciated, the 8-bit/10-bit encoding scheme has two 10-bit representations for every 8-bit word, which are termed the positive running disparity (RD+) and negative running disparity (RD−) and which can be used, for example, in data communications for DC balancing of a long data stream. The techniques disclosed herein can be used, in accordance with some embodiments, to encode an additional disparity bit in the RD+/RD− for a total of nine disparity bits such as can be seen with respect to disparity code13, discussed below with reference toFIG. 4).

As previously noted, the present disclosure is not limited to only a coded word7arranged in a 3×5 matrix. For example, consider FIGS.3′ and3″, which illustrate a 4×4 matrix48and a 5×5 matrix49, respectively, which can be used for bit partitioning, in accordance with some embodiments of the present disclosure. As will be appreciated in light of this disclosure, the greater the number of bits used for the coded word7used to pattern mask2, the greater the number of disparity values which can be encoded and the better the ECC protection (e.g., for 3-D imaging system100or other system which utilizes a coded word7produced using the disclosed techniques). However, as will be further appreciated, this also may increase the minimum detectable object (e.g., the smallest object that the imaging input device3can detect).

FIG. 4is a flow diagram illustrating a process for generating a coded word7for patterning a mask2for use in generating structured light, in accordance with an embodiment of the present disclosure. As can be seen, a 9-bit disparity word13is first converted to 10-bit data word11, for example, using an 8-bit/10-bit converter14. Thereafter, the ECC bits12(e.g., one or more checksum bits) are added thereto, for example, using ECC mechanism15, thereby producing a 15-bit coded word7. As previously noted, and in accordance with an embodiment, the 15-bit coded word7can be partitioned, for example, in a 3×5 matrix and used to pattern mask2, which in turn can be utilized to provide structured light, for example, for system100or any other suitable 3-D imaging system, as will be apparent in light of this disclosure. Also, as previously noted, the ECC bits12can be, in some example embodiments, one of the Hamming codes. In an example case, ECC bits12may be a Hamming code including one checksum bit for the even bits, another checksum bit for those divided by 4, and another checksum bit for those divided by 8. Numerous variations will be apparent in light of this disclosure.

FIG. 5demonstrates the alignment18of an example coded transmitter word7with respect to an example receiver matrix17, in accordance with an embodiment of the present disclosure. As can be seen in this example instance, the receiver matrix17(e.g., the matrix of imaging input device3) comprises a 6×10 arrangement of pixels (60 pixels total), and four pixels of the receiver matrix17cover one bit of the transmitter word7(e.g., here, a 15-bit transmitter word7), providing transmitted pattern18. In accordance with an embodiment, this may help to ensure that even when not properly aligned, at least one pixel of imaging input device3is fully covered, and the correct high and low lighting levels can be accurately measured, as will be explained below, for instance, with reference toFIG. 9A-9D.

FIG. 6Ais a block diagram of a receiver200configured in accordance with an embodiment of the present disclosure. As can be seen, receiver200includes: a first-in/first-out (FIFO) module19; a minimum-maximum level detection module21configured to output a control signal25; an ECC mechanism module22configured to output control signals24and26, the latter of which may be directed to a light source control module31operatively coupled therewith; and a 10-bit/8-bit encoder module23configured to output a control signal27. A discussion of each of these occurs below. As can further be seen, the computational pipeline of receiver200outputs a disparity13(e.g., 8-bit disparity word with an additional disparity bit), which can be used, for example, as discussed above with reference toFIG. 4. In some cases, receiver200can be integrated or otherwise operatively coupled, for example, with imaging input device3.

FIG. 6Billustrates a FIFO module19configured in accordance with an embodiment of the present disclosure. In the depicted example embodiment, FIFO module19is a 5-line pixel FIFO which can contain up to five lines of video data. It should be noted, however, that the present disclosure is not so limited, as in other embodiments, FIFO module19may have lesser (e.g., 4 lines or fewer) or greater (e.g., 6 lines or more) capacity for video data, as desired for a given target application or end-use. In any case, a moving window20may be transitioned along the data contents of FIFO module19and used to acquire data therefrom. For instance, as can be seen fromFIG. 6B, moving window20can be configured, in an example embodiment, to acquire fitly gross pixels (five lines of ten pixels each) from the video data within FIFO module19and to select fifteen net pixels30therefrom. As will be appreciated in light of this disclosure moving window20is not limited to only fifty gross pixels or fifteen net pixels30; other embodiments may have a moving window20configured to acquire a lesser or greater quantity of gross pixels and/or net pixels. In a more general sense, and in accordance with some embodiments, moving window20can be configured to acquire any amount of video data from FIFO module19, as desired for a given target application or end-use.

As can further be seen fromFIG. 6B, a new pixel value29is entered into the first line of FIFO module19at each clock cycle, the relevant quantity of net pixels (e.g., fifteen net pixels30, as inFIG. 6B) are taken from moving window20and passed through the computational pipeline of receiver200, and a new set of output signals13,24,25,26, and27is generated. The last bit from the first line of FIFO module19is then inserted as the first bit of the second line of FIFO module19(as generally indicated by the dotted arrow inFIG. 6B). In a similar fashion, the last bits of each of the second, third, and fourth lines of FIFO module19are inserted as the first bits of the third, fourth, and fifth lines, respectively, of FIFO module19. FIFO modules19of greater or lesser capacity can adopt a similar approach, in other embodiments, as appropriate for a given target application or end-use.

Returning toFIG. 6A, the data acquired by moving window20can be provided to minimum-maximum level detection module21, in accordance with an embodiment. Although the 8-bit/10-bit converter14(e.g., discussed above with reference toFIG. 3) generally ensures a similar quantity of white and black pixels, there may be some misalignment in transmitted pattern18in some instances. For example, considerFIGS. 7A and 7B, which represent operation of minimum-maximum level detection module21, in accordance with an embodiment of the present disclosure. In the depicted example case, eleven black pixels37and four white pixels38are present. The first average threshold39is calculated on all fifteen pixels, but misses a single pixel40. Thereafter, calculation of the means of all pixels above (e.g., mean value41) and below (e.g., mean value42) the first average threshold39is performed. The average between mean41and mean42can be the final brightness threshold43used, for example, for pixel detection. The standard deviation of values above the eleven black pixels37) and below (e.g., the four white pixels38) this second threshold43may be compared to another sanity threshold to ensure that the values are approximately within the same range, thereby helping to maintain good margin between the zeros and ones. This can be used, in accordance with an embodiment, to distinguish between: (1) transient pixels as inFIGS. 9A,9B, and9C (discussed below) where the standard deviation will be high as inFIG. 7B(e.g., when the variance is above threshold43, the values may not be distinctly zero and one); and (2) the case ofFIG. 9D(also discussed below) where the black and white threshold is distinct and the standard deviation will be low. In any case, the results may be output by minimum-maximum level detection module21, for example, as control signal25and may indicate whether good black-white threshold has been achieved, in accordance with an embodiment.

Returning toFIG. 6A, the data can be provided thereafter to an ECC module22, in accordance with an embodiment. ECC module22can implement, for example, a Hamming code and/or any other suitable error-correcting code or mechanism, as will be apparent in light of this disclosure. Also, as previously noted, ECC module22can be configured to output a control signal24, for example, which indicates whether the cyclic redundancy check (CRC) data is valid, in accordance with an embodiment. Furthermore, as previously noted. ECC module22can be configured to output a control signal26, for example, which indicates that the correction mechanism provided by ECC module22was utilized (e.g., that an error in the video data was detected and corrected). In some cases, control signal26may indicate, for example, that exactly one error was detected and thus ECC was required. As previously noted, other embodiments may utilize additional ECC bits, which may allow for detection and correction of more than one error (e.g., two, three, four, or more errors), in some instances. In some cases, this may help to provide additional robustness of data.

As can further be seen fromFIG. 6A, control signal26can be provided, in accordance with an embodiment, to a downstream light source power control module31.FIG. 8is a block diagram of a light source power control module31configured in accordance with an embodiment of the present disclosure. For each frame, the total number of pixel sets with valid CRC, for example, only after ECC correction (e.g., that is, frames with exactly one error) is counted by a counter32and compared to a high threshold33and a low threshold34, each of which can be set as desired for a given target application or end-use. If the resultant value provided by counter32is too high (e.g., higher than high threshold33), meaning that there is a sufficiently high quantity of correctable errors, then the power driver of the light source1(e.g., which may be a laser) may receive an UP-command signal35which increases the output power to improve the signal-to-noise (S/N) ratio. If instead the resultant value provided by counter32is too low (e.g., lower than low threshold34), meaning that the signal is high and there is a sufficiently low quantity of errors (e.g., no errors or only a few errors), then the power driver of light source1may receive a DN-command signal36which decreases the output power. In some instances, any resultant increase in the number of errors can be corrected using the disclosed techniques, and thus may not affect for else may negligibly affect) the final depth picture quality.

Returning toFIG. 6A, the data can be provided thereafter to a 10-bit/8-bit encoder module23. In accordance with an embodiment, 10-bit/8-bit encoding module23can implement any suitable 10-bit/8-bit encoding scheme, as will be apparent in light of this disclosure. Also, as previously noted, 10-bit/18-bit encoder module23can be configured to output a control signal27, for example, which indicates whether illegal 8-bit/10-bit code is present. Furthermore, 10-bit/8-bit encoder module23can be configured to output disparity13, as discussed above with reference toFIG. 4.

As previously noted, there may be some misalignment in transmitted pattern18in some cases. For instance, considerFIGS. 9A-9D, which illustrate four example cases of misaligned transmit7and receive 17 patterns. In accordance with some embodiments, three of the four example cases (e.g.,FIGS. 9A,9B, and9C) may be rejected by receiver200as missing at least one of: (1) control signal25indicating good black-white threshold; (2) control signal24indicating CRC data valid; and/or (3) control signal27indicating illegal 8-bit/10-bit code. However, the fourth example case (e.g.,FIG. 9D) should contain valid pixel data, in accordance with an embodiment.

Once a valid set of pixels is detected, sub-pixel approximation can be performed on the transient pixels, in accordance with an embodiment. For example, considerFIG. 10, which represents an example implementation of a sub-pixel alignment mechanism, in accordance with an embodiment of the present disclosure. As can be seen, the sub-pixel approximation mechanism can be executed, for example, on the transient pixels between detected valid pixels30, as generally denoted inFIG. 10by the dotted ellipses44,45,46, and47therein. In accordance with an embodiment, these transient pixels can be categorized, for example, as follows: (1) the scenario in which the pixel before and the pixel after the transient pixel are both white (e.g., as in ellipse44); (2) the scenario in which the pixel before and the pixel after the transient pixel are both black (e.g., as in ellipse45); (3) the scenario in which the transient pixel transitions from white to black (e.g., as in ellipse46); and (4) the scenario in which the transient pixel transitions from black to white (e.g., as in ellipse47). In the third described scenario (e.g., transition from white to black, as in ellipse46), the higher the displacement, the higher the pixel value as more white is present, and thus it may be desirable to add those picture values (e.g., add one value by adding the value) to the sum, in accordance with an embodiment. Conversely, in the fourth described scenario (e.g., transition from black to white, as in ellipse47), the higher the displacement, the lower the pixel value as more black is present, and thus it may be desirable to deduct those picture values (e.g., add the complement to 1) from the sum, in accordance with an embodiment. As will be appreciated in fight of this disclosure, the aforementioned sum defines the sub-pixel misalignment (e.g., when a pixel is partially 0 or partially 1). If the pixel is completely white, then the sum will be 1. If instead the pixel is completely black, then the sum will be 0. If the pixel is between those bounds, then the sum be fractional accordingly (e.g., if the pixel is in the middle, then the sum will be about 50% or ½). In any case, and in accordance with some embodiments averaging all values divided by the high minus low ratio provides the sub-pixel value.

Temporal Coded Light

FIG. 11illustrates a plurality of masks for use in generating temporal structured light, in accordance with an embodiment of the present disclosure. As can be seen, the techniques provided herein also can be used to provide temporal coded light by adding additional slides or masks with ECC patterns. Such an embodiment can be used, for example, to improve the picture quality.

In this example embodiment, the mask patterned with a coded word is implemented with fourteen masks, each pixel representing one bit (1-bit) of the coded word. As can be further seen, the coded word includes nine disparity bits and five ECC bits, so as to provide a total of fourteen masks. As previously explained, the coded word further may include an encoding bit (e.g., one 8-bit/10-bit encoding bit) to help ensure the presence of a transient pixel in the data for black and white thresholds level detection.

A sub-set of the masks (masks 1-9) are each patterned with a single bit of the data portion of the coded word and are configured to transmit temporal coded light. Another sub-set of the masks (masks 10-14) are each patterned with a single bit of the error correction portion of the coded word and are configured to provide an ECC directed to the coded word provided by the plurality of masks (specifically, masks 1-9). Thus, in this example case, the coded word includes nine bits of disparity and an additional five bits of ECC for a total of fourteen bits, and fourteen corresponding masks are provided to transmit those bits. The transmission of these bits is spaced in time, such that each bit is transmitted separately from other bits using its corresponding mask. The ECC mechanism can be implemented as previously described herein, taking the fourteen bits and generating a corrected nine bits of disparity.

Numerous other variations of providing temporal coded light will be apparent in light of this disclosure. For instance, in other embodiments, a subset of coded word bits can be provided on the masks, such that each mask is configured to transmit one or more bits of the coded word. Different masks may transmit a different number of bits, and they need not be limited to one bit per mask.

Example System

FIG. 12illustrates an example system600that may carry out the techniques for providing structured light encoded with a coded word including error-correcting code (ECC) to detect and correct errors as described herein, in accordance with some embodiments. In some embodiments, system600may be a media system, although system600is not limited to this context. For example, system600may be incorporated into a personal computer (PC), laptop computer, ultra-laptop computer, tablet, touch pad, portable computer, handheld computer, palmtop computer, personal digital assistant (PDA), cellular telephone, combination cellular telephone/PDA, television, smart device (e.g., smart phone, smart tablet or smart television), mobile internet device (MID), messaging device, data communication device, set-top box, game console, or other such computing environments capable of performing graphics rendering operations.

In some embodiments, system600comprises a platform602coupled to a display620. Platform602may receive content from a content device such as content services device(s)630or content delivery device(s)640or other similar content sources. A navigation controller650comprising one or more navigation features may be used to interact, for example, with platform602and/or display620. Each of these example components is described in more detail below. In some embodiments, platform602may comprise any combination of a chipset605, processor610, memory612, storage614, graphics subsystem615, applications616, and/or radio618. Chipset605may provide intercommunication among processor610, memory612, storage614, graphics subsystem615, applications616, and/or radio618. For example, chipset605may include a storage adapter (not depicted) capable of providing intercommunication with storage614.

Processor610may be implemented, for example, as Complex Instruction Set Computer (CISC) or Reduced Instruction Set Computer (RISC) processors, x86 instruction set compatible processors, multi-core, or any other microprocessor or central processing unit (CPU). In some embodiments, processor610may comprise dual-core processor(s), dual-core mobile processor(s), and so forth. Memory612may be implemented, for instance, as a volatile memory device such as, but not limited to, a Random Access Memory (RAM), Dynamic Random Access Memory (DRAM), or Static. RAM (SRAM). Storage614may be implemented, for example, as a non-volatile storage device such as, but not limited to, a magnetic disk drive, optical disk drive, tape drive, an internal storage device, an attached storage device, flash memory, battery backed-up SDRAM (synchronous DRAM), and/or a network accessible storage device. In some embodiments, storage614may comprise technology to increase the storage performance enhanced protection for valuable digital media when multiple hard drives are included, for example.

Graphics subsystem615may perform processing of images such as still or video for display. Graphics subsystem615may be a graphics processing unit (GPU) or a visual processing unit (VPU), for example. An analog or digital interface may be used to communicatively couple graphics subsystem615and display620. For example, the interface may be any of a High-Definition Multimedia Interface (HDMI), DisplayPort, wireless HDMI, and/or wireless HD compliant techniques. Graphics subsystem615could be integrated into processor610or chipset605. Graphics subsystem615could be as stand-alone card communicatively coupled to chipset605. The techniques for providing structured light encoded with a coded word including error-correcting code (ECC) to detect and correct errors described herein may be implemented in various hardware architectures. For example, the techniques for providing structured light encoded with a coded word including error-correcting code (ECC) to detect and correct errors as provided herein may be integrated within a graphics and/or video chipset. Alternatively, a discrete security processor may be used. In still another embodiment, the graphics and/or video functions including the techniques for providing structured light encoded with a coded word including error-correcting code (ECC) to detect and correct errors may be implemented by a general purpose processor, including a multi-core processor.

In some embodiments, display620may comprise any television or computer-type monitor or display. Display620may comprise, for example, a liquid crystal display (LCD) screen, electrophoretic display (EPD) or liquid paper display, flat panel display, touchscreen display, television-like device, and/or a television. Display620may be digital and/or analog. In some embodiments, display620may be a holographic or three-dimensional (3-D) display. Also, display620may be a transparent surface that may receive a visual projection. Such projections may convey various forms of information, images, and/or objects. For example, such projections may be a visual overlay for a mobile augmented reality (MAR) application. Under the control of one or more software applications616, platform602may display a user interface622on display620.

In some embodiments, content services device(s)630may be hosted by any national, international, and/or independent service and thus may be accessible to platform602via the Internet or other network, for example. Content services device(s)630may be coupled to platform602and/or to display620. Platform602and/or content services device(s)630may be coupled to a network660to communicate (e.g., send and/or receive) media information to and from network660. Content delivery device(s)640also may be coupled to platform602and/or to display620. In some embodiments, content services device(s)630may comprise a cable television box, personal computer (PC), network, telephone. Internet-enabled devices or appliance capable of delivering digital information and/or content, and any other similar device capable of unidirectionally or bi-directionally communicating content between content providers and platform602and/or display620, via network660or directly. It will be appreciated that the content may be communicated unidirectionally and/or bi-directionally to and from any one of the components in system600and a content provider via network660. Examples of content may include any media information including, for example, video, music, graphics, text, medical and gaming content, and so forth.

Content services device(s)630receives content such as cable television programming including media information, digital information, and/or other content. Examples of content providers may include any cable or satellite television or radio or Internet content providers. The provided examples are not meant to limit the present disclosure. In some embodiments, platform602may receive control signals from navigation controller650having one or more navigation features. The navigation features of controller650may be used to interact with user interface622, for example. In some embodiments, navigation controller650may be a pointing device that may be a computer hardware component (specifically human interface device) that allows a user to input spatial (e.g., continuous and multi-dimensional) data into a computer. Many systems such as graphical user interfaces (GUI) and televisions and monitors allow the user to control and provide data to the computer or television using physical gestures.

Movements of the navigation features of controller650may be echoed on a display e.g., display620) by movements of a pointer, cursor, focus ring, or other visual indicators displayed on the display. For example, under the control of software applications716, the navigation features located on navigation controller650may be mapped to virtual navigation features displayed on user interface622, for example. In some embodiments, controller650may not be a separate component but integrated into platform602and/or display620. Embodiments however, are not limited to the elements or in the context shown or described herein, as will be appreciated.

In some embodiments, drivers (not shown) may comprise technology to enable users to instantly turn on and off platform602like a television with the touch of a button after initial boot-up, when enabled, for example. Program logic may allow platform602to stream content to media adaptors or other content services device(s)630or content delivery device(s)640when the platform is turned “off”. In addition, chip set605may comprise hardware and/or software support for 5.1 surround sound audio and/or high definition 7.1 surround sound audio, for example. Drivers may include a graphics driver for integrated graphics platforms. In some embodiments, the graphics driver may comprise a peripheral component interconnect (PCI) express graphics card.

In various embodiments, any one or more of the components shown in system600may be integrated. For example, platform602and content services device(s)630may be integrated, or platform602and content delivery device(s)640may be integrated, or platform602, content services device(s)630, and content delivery device(s)640may be integrated, for example. In various embodiments, platform602and display620may be an integrated unit. Display620and content service device(s)630may be integrated, or display620and content delivery device(s)640may be integrated, for example. These examples are not meant to limit the present disclosure.

Platform602may establish one or more logical or physical channels to communicate information. The information may include media information and control information. Media information may refer to any data representing content meant for a user. Examples of content may include, for example, data from a voice conversation, videoconference, streaming video, email or text messages, voice mail message, alphanumeric symbols, graphics, image, video, text and so forth. Control information may refer to any data representing commands, instructions, or control words meant for an automated system. For example, control information may be used to route media information through a system or instruct a node to process the media information in a predetermined manner (e.g., using the techniques for providing structured light encoded with a coded word including error-correcting code (ECC) to detect and correct errors as described herein). The embodiments, however, are not limited to the elements or context shown or described inFIG. 12.

As described above, system600may be embodied in varying physical styles or form factors.FIG. 13illustrates embodiments of a small form factor device700in which system600may be embodied. In some embodiments, for example, device700may be implemented as a mobile computing device having wireless capabilities. A mobile computing device may refer to any device having a processing system and a mobile power source or supply, such as one or more batteries, for example.

As shown inFIG. 13, device700may comprise a housing702, a display704, an input/output (I/O) device706, and an antenna708. Device700also may comprise navigation features712. Display704may comprise any suitable display unit for displaying information appropriate for a mobile computing device. I/O device706may comprise any suitable I/O device for entering information into a mobile computing device. Examples for I/O device706may include an alphanumeric keyboard, a numeric keypad, a touch pad, input keys, buttons, switches, rocker switches, microphones, speakers, voice recognition device and software, and so forth. Information also may be entered into device700by way of microphone. Such information may be digitized by a voice recognition device. The embodiments are not limited in this context.

Various embodiments may be implemented using hardware elements, software elements, or a combination of both. Examples of hardware elements may include processors, microprocessors, circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, and so forth), integrated circuits (IC), application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), logic gates, registers, semiconductor device, chips, microchips, chip sets, and so forth. Examples of software may include software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, application program interfaces (API), instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. Whether hardware elements and/or software elements are used may vary from one embodiment to the next in accordance with any number of factors, such as desired computational rate, power levels, heat tolerances, processing cycle budget, input data rates, output data rates, memory resources, data bus speeds, and other design or performance constraints.

Some embodiments may be implemented, for example, using a machine-readable medium or article which may store an instruction or a set of instructions that, if executed by a machine, may cause the machine to perform a method and/or operations in accordance with an embodiment. Such a machine may include, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, processor, or the like, and may be implemented using any suitable combination of hardware and software. The machine-readable medium or article May include, for example, any suitable type of memory unit, memory device, memory article, memory medium, storage device, storage article, storage medium and/or storage unit, for example, memory, removable or non-removable media, erasable or non-erasable media, writeable or re-writ able media, digital or analog media, hard disk, floppy disk, Compact Disk Read Only Memory (CD-ROM), Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW), optical disk, magnetic media, magneto-optical media, removable memory cards or disks, various types of Digital Versatile Disk (DVD), a tape, a cassette, or the like. The instructions may include any suitable type of executable code implemented using any suitable high-level, low-level, object-oriented, visual, compiled, and/or interpreted programming language.

Further Example Embodiments

Example 1 is an imaging system comprising: a light source; a mask patterned with a coded word which includes an error-correcting code (ECC), wherein the patterned mask is configured to transmit light emitted by the light source as structured light encoded with the coded word; and an imaging input device which is configured to receive the structured light.

Example 2 includes the subject matter of any of Examples 1 and 3-16, wherein the coded word is configured to correct one data error and to detect two data errors.

Example 3 includes the subject matter of any of Examples 1-2 and 4-16, wherein the coded word is configured to detect a quantity of data errors, and an output power of the light source is at least one of increased and/or decreased based on that quantity of detected data errors.

Example 4 includes the subject matter of any of Examples 1-3 and 5-16, wherein the coded word comprises a plurality of data bits and ECC bits.

Example 5 includes the subject matter of any of Examples 4 and 6-7, wherein the plurality of data bits comprises a disparity code.

Example 6 includes the subject matter of Example 5 further including one 8-bit/10-bit encoding hit to provide at least one transient pixel for black and white intensity level detection.

Example 7 includes the subject matter of any of Examples 1-6 and 8-16, wherein the coded word comprises a 10-bit representation of 8-bit disparity and five ECC bits.

Example 8 includes the subject matter of any of Examples 1-7 and 9-16, wherein the coded word is provided in at least one of a 3×5 matrix, a 4×4 matrix, a 4×5 matrix, and/or a 5×5 matrix.

Example 9 includes the subject matter of any of Examples 1-8 and 10-16, wherein the coded word includes nine data bits comprising a disparity code, five ECC bits comprising a Hamming code, and one 8-bit/10-bit encoding bit.

Example 10 includes the subject matter of any of Examples 1-9 and 11-16, wherein the imaging input device comprises a still camera or a video camera.

Example 11 includes the subject matter of any of Examples 1-10 and 12-16, wherein the imaging input device comprises at least one of an optics assembly, an image sensor, and/or an image/video encoder.

Example 12 includes the subject matter of any of Examples 1-11 and 13-16, wherein the system further includes a processing unit operatively coupled with the imaging input device and configured to process imaging data captured thereby.

Example 13 includes the subject matter of Example 12, wherein the processing unit is configured to extract three-dimensional (3-D) surface shape of an object illuminated by the structured light.

Example 14 includes the subject matter of any of Examples 1-13 and 15-16, wherein the patterned mask comprises a plurality of masks, each mask pixel patterned with a single bit of the coded word, one sub-set of the plurality of masks being configured to transmit temporal coded light and another sub-set of the plurality of masks being patterned with ECC bits.

Example 15 is a computing device which includes the imaging system of any of Examples 1-14 and 16.

Example 16 includes the subject matter of Example 15, wherein the computing device comprises at least one of a laptop/notebook computer, a tablet computer, a mobile phone, a smartphone, a personal digital assistant (PDA), a cellular handset, a handheld gaming device, a gaming platform, a desktop computer, a smart television, and/or a videoconferencing system.

Example 17 is a method of three-dimensional (3-D) imaging, the method comprising: illuminating an Object with structured light encoded with a coded word including an error-correcting code (ECC); capturing structured light which is reflected from the object; and comparing the reflected structured light with the original structured light to extract a 3-D surface shape of the object illuminated by the structured light.

Example 18 includes the subject matter of any of Examples 17 and 19-31, wherein the coded word is configured to correct one data error and to detect two data errors.

Example 19 includes the subject matter of any of Examples 17-18 and 20-31, wherein the coded word comprises a plurality of data bits and ECC bits.

Example 20 includes the subject matter of any of Examples 19 and 21-22, wherein the plurality of data bits comprises a disparity code.

Example 21 includes the subject matter of Example 20 further including one 8-bit/10-bit encoding bit to provide at least one transient pixel for black and White intensity level detection.

Example 22 includes the subject matter of any of Examples 17-21 and 23-31, wherein the coded word comprises a 10-bit representation of 8-bit disparity and five ECC bits.

Example 23 includes the subject matter of any of Examples 17-22 and 24-31, wherein the coded word is provided in at least one of a 3×5 matrix, a 4×4 matrix, a 4×5 matrix, and/or a 5×5 matrix.

Example 24 includes the subject matter of any of Example 17-23 and 25-31, wherein the coded word includes nine data bits comprising a disparity code, five ECC bits comprising a Hamming code, and one 8-bit/10-bit encoding bit.

Example 25 includes the subject matter of any of Examples 17-24 and 26-31, wherein illuminating the object with structured light is performed using a light source and a mask patterned with the coded word, and wherein the patterned mask is configured to transmit light emitted by the light source as structured light encoded with the coded word.

Example 26 includes the subject matter of Example 25, wherein the light source comprises a laser.

Example 27 includes the subject matter of Example 25, wherein the coded word is configured to detect a quantity of data errors, and an output power of the light source is at least one of increased and/or decreased based on that quantity of detected data errors.

Example 28 includes the subject matter of any of Examples 17-27 and 29-31, wherein illuminating the object with structured light is performed using a light source and a plurality of masks, each mask pixel patterned with a single bit of the coded word, one sub-set of the plurality of masks being configured to transmit temporal coded light and another sub-set of the plurality of masks being patterned with ECC bits.

Example 29 includes the subject matter of any of Examples 17-28 and 30-31, wherein capturing the reflected structured light is performed using a still camera or to video camera.

Example 30 includes the subject matter of any of Examples 17-29 and 31, wherein extraction of 3-D surface shape of the object illuminated by the structured light is performed using triangulation.

Example 31 is a computer-readable medium encoded with instructions that, when executed by one or more processors, causes a process for three-dimensional (3-D) imaging to be carried out, the process including the method of any of Examples 17-30.

Example 32 is a structured-light system comprising, a transmitter comprising: a light source; and a mask patterned with a coded word which includes an error-correcting code (ECC), wherein the patterned mask is configured to transmit light emitted by the light source as structured light encoded with the coded word; and a receiver comprising; a first-in/first-out (FIFO) module configured to contain imaging data; a level detection module communicatively coupled with the FIFO module; an ECC module communicatively coupled with the level detection module; and a 10-bit/8-bit encoder module communicatively coupled with the ECC module; wherein the receiver is configured to output disparity code that is used in generating the coded word.

Example 33 includes the subject matter of any of Examples 32 and 34-51, wherein the coded word is configured to correct one data error and to detect two data errors.

Example 34 includes the subject matter of any of Examples 32-33 and 35-51, wherein the coded word is configured to detect a quantity of data errors, and an output power of the light source is at least one of increased and/or decreased based on that quantity of detected data errors.

Example 35 includes the subject matter of any of Examples 32-34 and 36-51, wherein the coded word comprises a plurality of data bits and ECC bits.

Example 36 includes the subject matter of Example 35, wherein the plurality of data bits comprises the disparity code which the receiver is configured to output.

Example 37 includes the subject matter of Example 36 further including one 8-bit/10-bit encoding bit to provide at least one transient pixel for black and white intensity level detection by the level detection module.

Example 38 includes the subject matter of any of Examples 32-37 and 39-51, wherein the FIFO module is configured to contain five lines of imaging data.

Example 39 includes the subject matter of any of Examples 32-38 and 40-51, wherein the FIFO module is configured to have a plurality of pixels from the imaging data acquired by a moving window.

Example 40 includes the subject matter of Example 39, wherein the moving window acquires fitly gross pixels from the imaging data.

Example 41 includes the subject matter of Example 39, wherein the moving window acquires fifteen net pixels from the imaging data.

Example 42 includes the subject matter of any of Examples 32-41 and 43-51, wherein the level detection module is configured to: calculate a first average threshold based on pixels acquired from the imaging data of the FIFO module; calculate a first mean value of pixels above the first average threshold; calculate a second mean value of pixels below the first average threshold; and calculate a second average threshold based on the first and second mean values.

Example 43 includes the subject matter of Example 42, wherein the second average threshold is used as a brightness threshold for pixel detection.

Example 44 includes the subject matter of Example 42, wherein a standard deviation of pixels above and pixels below the second average threshold is used to distinguish steady pixels from transient pixels.

Example 45 includes the subject matter of Example 44, wherein the level detection module is further configured to perform a sub-pixel approximation for transient pixels, wherein the sub-pixel approximation is used in pixel alignment between the transmitter and the receiver.

Example 46 includes the subject matter of any of Examples 32-45 and 47-51, wherein the level detection module is configured to output a signal indicating, black-white threshold.

Example 47 includes the subject matter of any of Examples 32-46 and 48-51, wherein the ECC module is configured to output a signal indicating that cyclic redundancy check (CRC) data is valid.

Example 48 includes the subject matter of any of Examples 32-47 and 49-51, wherein the ECC module is configured to output a signal indicating that error correction occurred.

Example 49 includes the subject matter of any of Examples 32-48 and 50-51, wherein the 10-bit/8-bit encoder module is configured to output a signal indicating existence of illegal 8-bit/10-bit code.

Example 50 includes the subject matter of any of Examples 32-49 and 51, wherein the structured-light system further includes a control module operatively coupled with the light source and the ECC module, wherein the control module is configured to control an output power of the light source.

Example 51 includes the subject matter of Example 50, wherein the control module includes a counter which counts a quantity of instances in which error correction by the ECC module occurred, and wherein the output power of the light source is at least one of increased and/or decreased by the control module based on that quantity of error correction instances.

Example 52 includes the subject matter of any of Examples 32-51, wherein the patterned mask comprises a plurality of masks, each mask pixel patterned with a single bit of the coded word, one sub-set of the plurality of masks being configured to transmit temporal coded light and another sub-set of the plurality of masks being patterned with ECC bits.