WO2021232247A1 - 点云着色方法、点云着色系统和计算机存储介质 - Google Patents

点云着色方法、点云着色系统和计算机存储介质 Download PDF

Info

Publication number
WO2021232247A1
WO2021232247A1 PCT/CN2020/091091 CN2020091091W WO2021232247A1 WO 2021232247 A1 WO2021232247 A1 WO 2021232247A1 CN 2020091091 W CN2020091091 W CN 2020091091W WO 2021232247 A1 WO2021232247 A1 WO 2021232247A1
Authority
WO
WIPO (PCT)
Prior art keywords
ground
point
point cloud
reflectivity
sub
Prior art date
Application number
PCT/CN2020/091091
Other languages
English (en)
French (fr)
Inventor
夏清
李延召
Original Assignee
深圳市大疆创新科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 深圳市大疆创新科技有限公司 filed Critical 深圳市大疆创新科技有限公司
Priority to PCT/CN2020/091091 priority Critical patent/WO2021232247A1/zh
Priority to CN202080005200.XA priority patent/CN114026410A/zh
Publication of WO2021232247A1 publication Critical patent/WO2021232247A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination

Definitions

  • the present invention relates to the technical field of laser ranging, in particular to a point cloud coloring method, a point cloud coloring system and a computer storage medium.
  • LiDAR perceives the distance information, position information, and reflectivity information of surrounding objects by actively emitting laser pulse signals and obtaining the pulse signals reflected by the measured object.
  • the reflectance information can provide important information about the surface of the measured object, thereby optimizing algorithms based on point cloud segmentation, clustering, and visualization.
  • the reflectance is generally used for the point cloud. Perform coloring.
  • the coloring schemes of existing lidar products are mostly based on the calculated reflectivity or coloring according to the echo width. The higher the reflectivity of the surface of the object in the space or the wider the echo width, then the color of the point during coloring The deeper.
  • this point cloud coloring method will face many practical problems. First, the same surface of the same object in the actual application scene will be affected by surface dirt or unevenness, resulting in different reflectance calculations; second, in the process of calculating reflectance, only the pulse width of the return light is considered. As well as the two factors of distance, the actual laser incident angle and other factors are not taken into consideration, which leads to inaccurate calculation of reflectivity. Therefore, the coloring scheme using only reflectance will have a great impact on the subsequent visual perception and subsequent operations such as detection and segmentation.
  • the first aspect of the embodiments of the present invention provides a point cloud coloring method, and the point cloud coloring method includes:
  • the point cloud is colored according to the adjusted reflectivity.
  • a second aspect of the embodiments of the present invention provides a point cloud coloring system, where the point cloud coloring system includes:
  • Memory used to store executable instructions
  • the processor is configured to execute the instructions stored in the memory, so that the processor executes the following steps:
  • the point cloud is colored according to the adjusted reflectivity.
  • a third aspect of the embodiments of the present invention provides a computer storage medium on which a computer program is stored, and when the program is executed by a processor, the point cloud coloring method provided in the first aspect of the embodiment of the present invention is implemented.
  • the point cloud coloring method, the point cloud coloring system, and the computer storage medium of the embodiments of the present invention can make the coloring of the point cloud in the display process more uniform and closer to the actual scene.
  • Fig. 1 shows a block diagram of a distance measuring device in an embodiment of the present invention
  • Figure 2 shows a schematic structural diagram of a distance measuring device in an embodiment of the present invention
  • Fig. 3 shows a schematic flowchart of a point cloud coloring method according to an embodiment of the present invention
  • Fig. 4 shows a structural block diagram of a point cloud coloring system according to an embodiment of the present invention.
  • the distance measuring device may include lidar, which is only used as an example, and other suitable distance measuring devices may also be applied to this application.
  • the distance measuring device is used to sense external environmental information, such as distance information, orientation information, reflection intensity information, and speed information of environmental targets.
  • the distance measuring device can detect the distance between the measured object and the distance measuring device by measuring the time of light propagation between the distance measuring device and the measured object, that is, the time-of-flight (TOF). distance.
  • the ranging device can also detect the distance from the measured object to the ranging device through other technologies, such as a ranging method based on phase shift measurement, or a ranging method based on frequency shift measurement, etc. , There is no restriction here.
  • the distance measuring device 100 includes a transmitting module, a scanning module, and a detection module.
  • the transmitting module is used to transmit a light pulse sequence to detect a target scene;
  • the scanning module is used to sequentially change the propagation path of the light pulse sequence emitted by the transmitting module.
  • the detection module is used to receive the light pulse sequence reflected by the object, and determine the distance and/or the distance between the object and the distance measuring device according to the reflected light pulse sequence Orientation to generate the point cloud points.
  • the transmitting module includes a transmitting circuit 110; the detecting module includes a receiving circuit 120, a sampling circuit 130 and an arithmetic circuit 140.
  • the transmitting circuit 110 may emit a light pulse sequence (for example, a laser pulse sequence).
  • the receiving circuit 120 can receive the light pulse sequence reflected by the detected object, that is, obtain the pulse waveform of the echo signal through it, and perform photoelectric conversion on the light pulse sequence to obtain the electrical signal, and then the electrical signal can be processed Output to the sampling circuit 130.
  • the sampling circuit 130 may sample the electrical signal to obtain the sampling result.
  • the arithmetic circuit 140 may determine the distance between the distance measuring device 100 and the detected object, that is, the depth, based on the sampling result of the sampling circuit 130.
  • the distance measuring device 100 may further include a control circuit 150 that can control other circuits, for example, can control the working time of each circuit and/or set parameters for each circuit.
  • a control circuit 150 can control other circuits, for example, can control the working time of each circuit and/or set parameters for each circuit.
  • the distance measuring device shown in FIG. 1 includes a transmitting circuit, a receiving circuit, a sampling circuit, and an arithmetic circuit for emitting a beam for detection
  • the embodiment of the present application is not limited to this, the transmitting circuit
  • the number of any one of the receiving circuit, the sampling circuit, and the arithmetic circuit can also be at least two, which are used to emit at least two light beams in the same direction or in different directions; wherein, the at least two light paths can be simultaneous Shooting can also be shooting at different times.
  • the light-emitting chips in the at least two transmitting circuits are packaged in the same module.
  • each emitting circuit includes a laser emitting chip, and the dies in the laser emitting chips in the at least two emitting circuits are packaged together and housed in the same packaging space.
  • the distance measuring device 100 may also include a scanning module for changing the propagation direction of at least one light pulse sequence (for example, a laser pulse sequence) emitted by the transmitting circuit, so as to control the field of view. Perform a scan.
  • the scanning area of the scanning module in the field of view of the distance measuring device increases with the accumulation of time.
  • the module including the transmitting circuit 110, the receiving circuit 120, the sampling circuit 130, and the arithmetic circuit 140, or the module including the transmitting circuit 110, the receiving circuit 120, the sampling circuit 130, the arithmetic circuit 140, and the control circuit 150 may be referred to as the measuring circuit.
  • the distance module the distance measurement module can be independent of other modules, for example, the scanning module.
  • a coaxial optical path can be used in the distance measuring device, that is, the light beam emitted by the distance measuring device and the reflected light beam share at least part of the optical path in the distance measuring device.
  • the distance measuring device may also adopt an off-axis optical path, that is, the light beam emitted by the distance measuring device and the reflected light beam are transmitted along different optical paths in the distance measuring device.
  • Fig. 2 shows a schematic diagram of an embodiment in which the distance measuring device of the present invention adopts a coaxial optical path.
  • the ranging device 200 includes a ranging module 210, which includes a transmitter 203 (which may include the above-mentioned transmitting circuit), a collimating element 204, a detector 205 (which may include the above-mentioned receiving circuit, sampling circuit, and arithmetic circuit), and Light path changing element 206.
  • the ranging module 210 is used to emit a light beam, receive the return light, and convert the return light into an electrical signal.
  • the transmitter 203 can be used to emit a light pulse sequence.
  • the transmitter 203 may emit a sequence of laser pulses.
  • the laser beam emitted by the transmitter 203 is a narrow-bandwidth beam with a wavelength outside the visible light range.
  • the collimating element 204 is arranged on the exit light path of the emitter, and is used to collimate the light beam emitted from the emitter 203, and collimate the light beam emitted from the emitter 203 into parallel light and output to the scanning module.
  • the collimating element is also used to condense at least a part of the return light reflected by the probe.
  • the collimating element 204 may be a collimating lens or other elements capable of collimating light beams.
  • the transmitting light path and the receiving light path in the distance measuring device are combined before the collimating element 204 through the light path changing element 206, so that the transmitting light path and the receiving light path can share the same collimating element, so that the light path More compact.
  • the emitter 203 and the detector 205 use their respective collimating elements, and the optical path changing element 206 is arranged on the optical path behind the collimating element.
  • the optical path changing element can use a small area mirror to The transmitting light path and the receiving light path are combined.
  • the light path changing element may also use a reflector with a through hole, where the through hole is used to transmit the emitted light of the emitter 203 and the reflector is used to reflect the return light to the detector 205. In this way, the shielding of the back light by the support of the small reflector in the case of using the small reflector can be reduced.
  • the optical path changing element deviates from the optical axis of the collimating element 204.
  • the optical path changing element may also be located on the optical axis of the collimating element 204.
  • the distance measuring device 200 further includes a scanning module 202.
  • the scanning module 202 is placed on the exit light path of the distance measuring module 210.
  • the scanning module 202 is used to change the transmission direction of the collimated beam 219 emitted by the collimating element 204 and project it to the external environment, and project the return light to the collimating element 204 .
  • the returned light is collected on the detector 205 via the collimating element 204.
  • the scanning module 202 may include at least one optical element for changing the propagation path of the light beam, wherein the optical element may change the propagation path of the light beam by reflecting, refraction, or diffracting the light beam, for example,
  • the optical element includes at least one light refraction element having a non-parallel exit surface and an entrance surface.
  • the scanning module 202 includes a lens, a mirror, a prism, a galvanometer, a grating, a liquid crystal, an optical phased array (Optical Phased Array), or any combination of the foregoing optical elements.
  • the optical element is moving, for example, the at least part of the optical element is driven to move by a driving module, and the moving optical element can reflect, refract, or diffract the light beam to different directions at different times.
  • the multiple optical elements of the scanning module 202 can rotate or vibrate around a common axis 209, and each rotating or vibrating optical element is used to continuously change the propagation direction of the incident light beam.
  • the multiple optical elements of the scanning module 202 may rotate at different rotation speeds or vibrate at different speeds.
  • at least part of the optical elements of the scanning module 202 may rotate at substantially the same rotation speed.
  • the multiple optical elements of the scanning module may also rotate around different axes.
  • the multiple optical elements of the scanning module may also rotate in the same direction or in different directions; or vibrate in the same direction, or vibrate in different directions, which is not limited herein.
  • the scanning module 202 includes a first optical element 214 and a driver 216 connected to the first optical element 214.
  • the driver 216 is used to drive the first optical element 214 to rotate around the rotation axis 209 to change the first optical element 214.
  • the direction of the beam 219 is collimated.
  • the first optical element 214 projects the collimated beam 219 to different directions.
  • the angle between the direction of the collimated beam 219 changed by the first optical element and the rotation axis 209 changes with the rotation of the first optical element 214.
  • the first optical element 214 includes a pair of opposed non-parallel surfaces through which the collimated light beam 219 passes.
  • the first optical element 214 includes a prism whose thickness varies along at least one radial direction.
  • the first optical element 214 includes a wedge prism, and the collimated beam 219 is refracted.
  • the scanning module 202 further includes a second optical element 215, the second optical element 215 rotates around the rotation axis 209, and the rotation speed of the second optical element 215 is different from the rotation speed of the first optical element 214.
  • the second optical element 215 is used to change the direction of the light beam projected by the first optical element 214.
  • the second optical element 215 is connected to another driver 217, and the driver 217 drives the second optical element 215 to rotate.
  • the first optical element 214 and the second optical element 215 can be driven by the same or different drivers, so that the rotation speed and/or rotation of the first optical element 214 and the second optical element 215 are different, so that the collimated light beam 219 is projected to the outside space.
  • the controller 218 controls the drivers 216 and 217 to drive the first optical element 214 and the second optical element 215, respectively.
  • the rotation speed of the first optical element 214 and the second optical element 215 can be determined according to the expected scanning area and pattern in actual applications.
  • the drivers 216 and 217 may include motors or other drivers.
  • the second optical element 215 includes a pair of opposite non-parallel surfaces through which the light beam passes. In one embodiment, the second optical element 215 includes a prism whose thickness varies in at least one radial direction. In one embodiment, the second optical element 215 includes a wedge prism.
  • the scanning module 202 further includes a third optical element (not shown) and a driver for driving the third optical element to move.
  • the third optical element includes a pair of opposite non-parallel surfaces, and the light beam passes through the pair of surfaces.
  • the third optical element includes a prism whose thickness varies in at least one radial direction.
  • the third optical element includes a wedge prism. At least two of the first, second, and third optical elements rotate at different rotation speeds and/or rotation directions.
  • the scanning module includes two or three light refraction elements arranged in sequence on the exit light path of the light pulse sequence.
  • at least two of the light refraction elements in the scanning module rotate during the scanning process to change the direction of the light pulse sequence.
  • the scanning path of the scanning module is different at least partly at different moments.
  • the rotation of each optical element in the scanning module 202 can project light to different directions, such as the direction of the projected light 211 and the direction 213. Space to scan.
  • the light 211 projected by the scanning module 202 hits the detection object 201, a part of the light is reflected by the detection object 201 to the distance measuring device 200 in a direction opposite to the projected light 211.
  • the return light 212 reflected by the detection object 201 is incident on the collimating element 204 after passing through the scanning module 202.
  • the detector 205 and the transmitter 203 are placed on the same side of the collimating element 204, and the detector 205 is used to convert at least part of the return light passing through the collimating element 204 into electrical signals.
  • an anti-reflection coating is plated on each optical element.
  • the thickness of the antireflection coating is equal to or close to the wavelength of the light beam emitted by the emitter 203, which can increase the intensity of the transmitted light beam.
  • a filter layer is plated on the surface of an element located on the beam propagation path in the distance measuring device, or a filter is provided on the beam propagation path for transmitting at least the wavelength band of the beam emitted by the transmitter, Reflect other bands to reduce the noise caused by ambient light to the receiver.
  • the transmitter 203 may include a laser diode through which nanosecond laser pulses are emitted.
  • the laser pulse receiving time can be determined, for example, the laser pulse receiving time can be determined by detecting the rising edge time and/or the falling edge time of the electrical signal pulse.
  • the distance measuring device 200 can calculate the TOF using the pulse receiving time information and the pulse sending time information, so as to determine the distance between the probe 201 and the distance measuring device 200.
  • the distance and orientation detected by the distance measuring device 200 can be used for remote sensing, obstacle avoidance, surveying and mapping, modeling, navigation, and the like.
  • Existing distance measuring devices usually color the point cloud based on reflectivity when displaying the point cloud.
  • the return light energy value is usually calculated according to the relationship between the pre-calibrated pulse width and the return light energy, and the energy value is multiplied by the square of the distance to obtain the reflectivity.
  • the return light energy is not only related to distance and reflectivity, but also affected by incident angle, laser spot size, etc. The incident angle and laser spot size cannot be obtained directly, so some random errors will be introduced when calculating reflectivity. .
  • the direct use of reflectivity for point cloud coloring will introduce noise, lead to poor visual effects, and adversely affect subsequent point cloud applications.
  • an embodiment of the present invention provides a point cloud coloring method.
  • the point cloud coloring method of the present invention will be described with reference to FIG. 3 first.
  • the point cloud coloring method 300 includes the following steps:
  • step S310 point cloud data is acquired, where the point cloud data includes position information and reflectance information of the point cloud;
  • step S320 the point cloud is divided into at least two point clouds of location intervals according to the location information
  • step S330 the reflectivity of the point cloud in each position interval is adjusted to reduce the difference in the reflectivity of at least part of the point cloud in the same position interval;
  • step S340 the point cloud is colored according to the adjusted reflectance.
  • the point cloud coloring method 300 of the embodiment of the present invention can reduce the difference in reflectivity of at least part of the point cloud in the same position interval, and avoid the problem of different reflectivity measured on the same object due to different incident angles.
  • the coloring of the cloud is more uniform during the display process, closer to the actual scene, improving the visual effect, and conducive to subsequent applications such as detection and segmentation.
  • step S310 laser pulses may be actively emitted to the measured object through the above-mentioned distance measuring device, the laser echo signal is captured, and the information of the measured object is obtained according to the echo signal, for example, according to the difference between laser emission and reception.
  • the time difference calculates the distance of the measured object, and obtains the angle information of the measured object based on the known emission direction of the laser.
  • a point cloud a large amount of space location information such as the distance and angle information of the detection point can be obtained, which is called a point cloud, and the detection point can be called a point cloud point.
  • the original point cloud data collected by the distance measuring device acquired in step S310 includes pulse width information (that is, the difference in time between the rising edge and the falling edge of the pulse signal to reach a certain voltage value) and distance information, and point cloud data
  • pulse width information that is, the difference in time between the rising edge and the falling edge of the pulse signal to reach a certain voltage value
  • distance information that is, the difference in time between the rising edge and the falling edge of the pulse signal to reach a certain voltage value
  • point cloud data The reflectance information in can be calculated according to the pulse width information and the distance information.
  • the pulse width information is used to calculate the return light energy of the reflected signal, and the return light energy is related to the distance, reflectivity, incident angle, laser spot size, etc. of the measured object. Since the incident angle and laser spot size cannot be directly obtained, the return light energy received by the lidar only considers the influence of two factors, distance and reflectivity, that is, the return light energy is considered to be proportional to the reflectivity and inversely proportional to the square of the distance. As shown in formula (1):
  • E intensity is the energy value
  • r is the reflectivity
  • R is the distance between the lidar and the measured object
  • k is the coefficient related to the lidar.
  • the data of the lidar at normal incidence at different distances can be collected in advance from a fixed point, and the relationship between the pulse width and the return light energy can be calibrated.
  • the return light energy can be calculated according to the above-mentioned pre-calibrated relationship.
  • the lidar In the process of calibrating the relationship between pulse width and energy, only normal incidence is considered, and oblique incidence is not considered.
  • the lidar emits light pulse signals to multiple targets with known true values of reflectivity, receives the reflected pulse signals reflected by the targets, and samples the reflected pulse signals to obtain the sampling results.
  • the pulse width of the reflected pulse signal is determined based on the sampling result, and the return light energy is obtained based on the ratio of the true value of the reflectivity of each target object to the square of the true value of the distance between each target object and the distance measuring device.
  • the light energy is fitted to the relationship curve to obtain the relationship between the pulse width and the return light energy.
  • the target object may be a black-and-white foam or other material with a known true reflectivity value.
  • a cubic polynomial piecewise fitting is used under each of the above conditions.
  • the stretched waveform needs to be corrected before it can be applied to the pulse width-return energy curve.
  • the difference between the actual measured pulse width and the pulse width corrected by the height information can be used as a parameter to correct it, and the final output pulse width can be determined according to the measured pulse width and the corrected pulse width. And limit the output pulse width within a range.
  • the return light energy values at different points in the point cloud can be calculated. Then multiply the calculated return light energy value with the square of the distance from the point to obtain the reflectivity value at the point, as shown in formula (2):
  • pulse_width is the pulse width of the echo.
  • the calculation of reflectivity is transformed into a function of distance and pulse width.
  • Table 1 shows the reflectance values obtained by measuring different reflectance materials at the same position by different lidars. It can be seen from Table 1 that the reflectivity measured by different lidars for materials of the same color is quite different, that is, the consistency between different devices is poor. Therefore, after the reflectance is obtained by the above-mentioned method, the reflectance of different lidars still needs to be further corrected for the consistency of individual differences.
  • the linear factor correction method can be used in the consistency correction, that is, the reflectance is corrected by the linear factor calibrated for the lidar, so that the reflectance is closer to the true value as a whole.
  • the corrected reflectance is shown in Table 2:
  • the point cloud is divided into at least two positional point clouds according to the position information of the point cloud in the point cloud data.
  • the target area in the point cloud may be determined first, and the target area may be divided into at least two location intervals.
  • the target area may be uncertain, and the position interval may be segmented for the entire point cloud of the current frame.
  • the target area can be selected according to application requirements. For example, for a moving vehicle, the target area can be a road area.
  • the division of the location interval can also be set according to actual application requirements.
  • the above-mentioned location interval may be an above-ground interval and a ground interval
  • the point cloud in the above-ground interval is an above-ground point, such as a point cloud including vehicles, trees, etc.
  • points in the ground interval Clouds are ground points.
  • any suitable method can be used to segment the above-ground points and the ground points in the point cloud. For example, you can first segment the ground points from the point cloud, and consider the point cloud points other than the ground points as above-ground points.
  • the step of segmenting ground points from the point cloud may include: firstly, determining at least part of the ground points according to the height of the point cloud points in the point cloud data; then, performing plane fitting on the remaining point cloud points and filtering Divide the point cloud points whose distance from the fitted plane is greater than the threshold. After that, the remaining point cloud points are the ground points.
  • determining at least part of the ground points may include: first, rasterize the horizontal plane of the point cloud space, and for each grid, take the height of the point cloud point with the lowest height among all the point cloud points as the reference for the grid Height, the minimum height distribution map of the point cloud space is obtained; then based on the minimum height distribution map, a certain height threshold is set, and the height difference between each grid and the reference height of the corresponding grid is filtered out. Threshold point cloud points. Then, on this basis, according to the absolute height of all the point cloud points in the point cloud space, remove the point cloud points whose absolute height is greater than a certain threshold. The point cloud points retained afterwards are ground points. After the ground point is determined, the point cloud points other than the ground point are the ground points.
  • the embodiment of the present invention is not limited by the specific point cloud segmentation method used. Whether it is an existing point cloud segmentation method or a point cloud segmentation method developed in the future, it can be applied to the point cloud coloring according to the embodiment of the present invention. Method.
  • step S330 the reflectivity of the point cloud in each position interval is adjusted respectively to reduce the difference in the reflectivity of at least part of the point cloud in the same position interval.
  • the adjustment performed in step S330 may include reducing the difference in reflectivity of at least part of the above-ground points, and reducing the difference in the reflectivity of at least part of the ground points.
  • the difference in reflectivity may specifically include reducing the difference in reflectivity of the point cloud of the same object in the same position interval.
  • the reflectance calculation deviation may be affected by the influence of the surface of the object, such as in In the road scene, the vehicle body, the reflectivity of the road surface, and the reflectivity of the trees are messy and noisy, which affects the visual perception, and will affect the subsequent tasks such as detection, recognition, and segmentation based on reflectivity characteristics.
  • the embodiment of the present invention after adjusting the reflectivity of the point cloud in each position interval, the difference in the reflectivity of at least part of the point cloud in the same position interval is reduced.
  • the adjustment made reduces the difference between the ground points or the difference between the ground points, thereby reducing the problem that the point cloud reflectivity of the same object is too large due to the different incident angles, so that the processed point cloud The reflectivity is more uniform.
  • the adjustment of the reflectivity of the point cloud also includes increasing the difference of the reflectivity of the point cloud between different location intervals.
  • the adjustment of the point cloud reflectivity includes increasing the difference between the reflectivity of the above-ground point and the ground point.
  • reducing the difference in reflectivity of point clouds in the same position interval and increasing the difference in reflectivity of point clouds between different position intervals includes, but is not limited to, changing the reflectivity of point clouds in different position intervals according to different trends. Perform normalization processing. By increasing the difference in reflectivity between different location intervals, it is possible to make the point cloud difference in different location intervals more obvious when the point cloud is subsequently colored by using reflectivity.
  • each position interval it can also be divided into multiple sub-position intervals, and the reflectivity can be further adjusted in the unit of the sub-position interval, so as to reduce the difference in the reflectivity of the point cloud of the same object and expand the difference.
  • the difference in reflectivity of the point cloud of the object can also be divided into multiple sub-position intervals, and the reflectivity can be further adjusted in the unit of the sub-position interval, so as to reduce the difference in the reflectivity of the point cloud of the same object and expand the difference.
  • the difference in reflectivity of the point cloud of the object can also be divided into multiple sub-position intervals, and the reflectivity can be further adjusted in the unit of the sub-position interval, so as to reduce the difference in the reflectivity of the point cloud of the same object and expand the difference. The difference in reflectivity of the point cloud of the object.
  • the ground point may be divided into a plurality of ground points in the first sub-location interval, and the reflectivity of the ground point in each first sub-location interval may be adjusted respectively.
  • the first sub-location interval may be divided according to the distance between the point cloud and the distance measuring device that generates the point cloud.
  • the ground points can be divided into multiple two-dimensional grids of ground points, and each first sub-location interval includes at least one grid, that is, each grid may form a first sub-location interval, or Multiple grids together form a first sub-location interval. Since the actual ground is not a regular plane, it is possible to map the ground points to the horizontal plane and divide the horizontal plane into multiple two-dimensional grids, and the ground points mapped to each two-dimensional grid are divided into corresponding grids Ground point.
  • the grids divided in the horizontal plane can have the same shape and size.
  • ground points In a road scene, ground points generally include ground points on ordinary roads and ground points with road markings such as lane lines and zebra crossings.
  • the point cloud in each first sub-location interval may include only ordinary road points, only road marking points, or both ordinary road points and road marking points. .
  • the embodiment of the present invention adjusts the reflectivity of the ground points in the multiple first sub-location intervals to reduce the difference between the internal reflectivity of the ordinary road point and the road marking point, and make the ordinary road point and the road marking point different from each other. The difference between is more obvious.
  • the reflectivity of the ground points in each first sub-location interval can be adjusted as follows:
  • the first sub-location interval includes ground points on the same surface, for example, only ordinary road points or road marking points are included. Therefore, the reflectivity of the ground point in the first sub-location interval is adjusted according to the same trend. For example, the reflectivity of all ground points in the first sub-location interval may be adjusted to a larger value interval or a smaller value interval of the reflectivity in the first sub-location interval. At this time, multiple first sub-location intervals can be integrated to determine the adjustment direction.
  • the reflectivity can be adjusted toward a larger value interval; when the first sub-location interval is determined When the reflectivity of the position interval is small, the reflectivity can be adjusted toward the smaller numerical interval.
  • the first sub-location interval when the difference between the reflectances of the ground points in the first sub-location interval exceeds the preset threshold, it is considered that the first sub-location interval includes ground points on different surfaces, for example, it includes both ordinary road points and road surfaces. Therefore, the reflectivity of the ground point in the first sub-location interval is adjusted according to different trends, so as to expand the difference in reflectivity of different surfaces, and at the same time, can reduce the difference in reflectivity of the same surface. Specifically, the reflectivity of the ground point in the first sub-location interval may be adjusted toward two numerical ranges where the reflectivity of the ground point in the first sub-location interval is located at both ends.
  • the first sub-location interval includes both the ground points of the ordinary road surface and the ground points of the road sign, where the reflectivity of the ordinary road surface is small, and the reflectivity of the road marking marking line is large.
  • the difference between the two Exceeding the preset threshold, at this time, the reflectivity of the ground points with lower reflectivity in the first sub-location interval (that is, the ground points on the ordinary road surface) are all converged toward the numerical interval with the smallest reflectivity in the first sub-location interval Adjustment, so as to reduce the difference between the reflectivity of the ground points on the ordinary road; at the same time, the reflectivity of the ground points with greater reflectivity in the first sub-location interval (that is, the ground points of the road markings) are all directed toward the first sub-location.
  • Convergence adjustment is carried out for the numerical interval with the highest reflectivity in the position interval, thereby reducing the difference between the reflectivity of the ground points of the road markings; in addition, after the convergent adjustments are made to the numerical intervals at the two ends, it is obvious that the ordinary road surface is also increased. The difference between the ground point and the ground point of the road marking.
  • the above-mentioned larger numerical interval of the reflectance of the ground points in different first sub-location intervals may also be convergently adjusted, and the above-mentioned adjustment of the reflectance of the ground points in different first sub-location intervals may be performed.
  • the smaller numerical interval is adjusted for convergence to make the reflectance of different first sub-position intervals more uniform.
  • the ground points of the ordinary road surface and the ground points of the road markings in each first sub-location interval, whether the first sub-location interval includes the same kind of ground points or different ground points, they will be ordinary Adjust the smaller numerical interval of the reflectivity of the ground points of the road surface, and adjust the numerical interval of the super-large reflectivity of the ground points of the road marking. Therefore, after the above adjustment, the difference between the ordinary road point and the road marking point between different first sub-location intervals can be reduced.
  • an above-ground point it can be divided into at least two above-ground points in the second sub-location interval, and the reflectivity of the above-ground point in each second sub-location interval can be adjusted respectively.
  • the above-ground points can be divided according to height.
  • the above-ground point may be divided into at least two above-ground points in the second sub-location interval according to the height of the above-ground point above the plane where the ground point is located based on the plane where the ground point is located.
  • the ground point when applied to automatic driving, the height of the more concerned vehicles in the road scene is generally distributed within a certain height range above the road surface, and the attention to objects higher than this height range is low, so the ground point can be
  • the above-ground point within the first height above the plane where it is located is determined as the above-ground point in the first and second sub-location interval
  • the above-ground point between the first height and the second height above the plane where the ground point is located is determined as the second The aboveground point of the second sub-location interval.
  • the height range of the first and second sub-location intervals may be 0-2 meters
  • the height range of the second and second sub-location intervals may be 2-5 meters.
  • the height interval of the above-ground point can be set reasonably according to needs, and it is not specifically limited here.
  • the ground point may also include more than two height intervals, which is not specifically limited here.
  • the adjustment of the reflectivity of the second sub-location interval may include reducing the difference in reflectivity of the above-ground points in the same second sub-location interval, and expanding the difference in the reflectivity of the above-ground points in different second sub-location intervals.
  • the above-ground points in the first and second sub-location intervals generally include the point cloud of the vehicle
  • the above-ground points in the second and second sub-location interval generally include the point clouds of the trees on both sides of the road. Therefore, the above adjustment can reduce the point cloud of the vehicle.
  • the difference between the point cloud of the interior and the interior of the tree expands the difference between the point cloud of the vehicle and the point cloud of the tree.
  • the adjustment of the reflectivity of the second sub-location interval may be similar to the adjustment of the reflectivity of the first sub-location interval above, for example, a plurality of second sub-location intervals may be divided, respectively. It is determined that each second sub-location interval includes the point cloud of the same object or the point cloud of different objects, and the difference between the point clouds of the same object is reduced, and the difference between the point clouds of different objects is enlarged.
  • the incident angle of the light emitted by the distance measuring device on the surface of the measured object is also affected by the position of the measured object in the field of view, for example, the incident angle near the road surface is small, and the incident angle at a distance is relatively large.
  • the angle of incidence near the center of the field of view is smaller, and the angle of incidence near the edge of the field of view is larger; for the same building, the angle of incidence is smaller at a lower position, and the angle of incidence is larger at a higher position.
  • the different incident angles will affect the return light energy, which in turn affects the reflectivity measured based on the return light energy.
  • the point cloud coloring method 300 may further include: determining an adjustment coefficient according to the position information in the point cloud data, and using the adjustment coefficient to adjust the reflectivity of the point cloud, wherein at least two The adjustment coefficients of the point cloud at different positions are different.
  • the position information includes at least one of the following: distance information, height information, and horizontal position information in the current field of view.
  • the adjustment coefficient may change with the change of the position information, for example, it may change gradiently or linearly with the change of the distance, height, or horizontal position information. Multiple adjustment coefficients can be determined according to different location information, and multiple adjustments can be performed. The adjustment of the reflectance using the adjustment coefficient related to the distance information may be performed before or after the adjustment described in step S330 is performed.
  • the reflectivity of the point cloud can be normalized and adjusted according to the following formula (3) at different heights:
  • point.z is the height value of the current point
  • z max and z_min respectively refer to the maximum and minimum point cloud height of the current frame
  • R is the height normalization The reflectance value afterwards.
  • step S340 the point cloud is colored according to the adjusted reflectance.
  • the pixel parameter corresponding to the reflectivity interval is assigned to the point cloud point.
  • the pixel parameter corresponding to each reflectivity interval may include at least one of pixel color and pixel grayscale.
  • the color of a pixel may be represented by three-channel color values, and the three-channel color values corresponding to different pixel colors are different. If a point cloud point belongs to a certain reflectivity interval, the three-channel color value corresponding to the reflectivity interval is assigned to the point cloud point, so that the color displayed by the point cloud point is the color corresponding to the three-channel color value. Since different measured objects have different reflectivities, different measured objects will be displayed in different colors.
  • the distribution of reflectivity can be made uniform in the entire space, so that the reflectivity of the same object in the scene is more consistent, and the contrast between different objects is more obvious, which is more conducive to detection. Improve the stability and accuracy of algorithms such as segmentation.
  • the point cloud coloring system can be implemented as an electronic device such as a computer, a server, or a vehicle-mounted terminal.
  • the point cloud shading system 400 as shown in FIG. 4 further includes one or more processors 410, one or more memories 420, and one or more processors 410 work together or individually.
  • the point cloud coloring system 400 may further include at least one of an input device (not shown), an output device (not shown), and an image sensor (not shown), and these components are connected through a bus system and/or other forms.
  • the connecting mechanism (not shown) is interconnected.
  • the memory 420 is used to store program instructions executable by the processor, for example, used to store corresponding steps and program instructions for implementing the point cloud coloring method according to the embodiments of the present invention. It may include one or more computer program products, and the computer program products may include various forms of computer-readable storage media, such as volatile memory and/or non-volatile memory.
  • the volatile memory may include random access memory (RAM) and/or cache memory (cache), for example.
  • the non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, and the like.
  • the input device may be a device used by a user to input instructions, and may include one or more of a keyboard, a mouse, a microphone, and a touch screen.
  • the output device may output various information (for example, images or sounds) to the outside (for example, a user), and may include one or more of a display, a speaker, etc., for outputting the colored point cloud as an image or video.
  • the communication interface (not shown) is used to communicate with other devices, including wired or wireless communication.
  • the ranging device can access a wireless network based on a communication standard, such as WiFi, 2G, 3G, 4G, 5G, or a combination thereof.
  • the communication interface receives a broadcast signal or broadcast related information from an external broadcast management system via a broadcast channel.
  • the communication interface further includes a near field communication (NFC) module to facilitate short-range communication.
  • the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.
  • RFID radio frequency identification
  • IrDA infrared data association
  • UWB ultra-wideband
  • Bluetooth Bluetooth
  • the processor 410 may be a central processing unit (CPU), an image processing unit (GPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other forms of processing with data processing capabilities and/or instruction execution capabilities Unit, and can control other components in the point cloud shading system to perform desired functions.
  • the processor can execute the instructions stored in the memory to execute the point cloud coloring method of the embodiment of the present invention described herein. For these methods, refer to the description in the foregoing embodiment, and details are not repeated here.
  • the processor can include one or more embedded processors, processor cores, microprocessors, logic circuits, hardware finite state machines (FSM), digital signal processors (DSP), or combinations thereof.
  • the processor includes a field programmable gate array (FPGA), wherein the arithmetic circuit of the distance measuring device may be a part of the field programmable gate array (FPGA).
  • the point cloud shading system 400 includes one or more processors that work together or separately.
  • the memory is used to store program instructions; the processor is used to execute the program instructions stored in the memory. When the program instructions are executed
  • the processor is used to implement the corresponding steps in the point cloud coloring method according to the embodiment of the present invention, in order to avoid repetition, the specific description of these methods can refer to the related description of the foregoing embodiment.
  • the point cloud coloring system of the embodiment of the present invention can be applied to a movable platform.
  • a movable platform with a point cloud coloring system can measure the external environment, for example, measuring the distance between the mobile platform and obstacles for obstacle avoidance and other purposes, and for two-dimensional or three-dimensional surveying and mapping of the external environment.
  • the movable platform includes an unmanned vehicle or a vehicle equipped with an Advanced Driving Assistance System (ADAS).
  • ADAS Advanced Driving Assistance System
  • the movable platform may also include at least one of an unmanned aerial vehicle, a robot, a boat, and a camera.
  • the point cloud coloring system in the embodiment of the present invention is used to execute the foregoing method, and the mobile platform includes the point cloud coloring system, both the point cloud coloring system and the mobile platform have the same advantages as the foregoing method.
  • the embodiment of the present invention also provides a computer storage medium on which a computer program is stored.
  • One or more computer program instructions may be stored on the computer-readable storage medium, and the processor may run the program instructions stored in the memory to implement the functions (implemented by the processor) in the embodiments of the present invention described herein And/or other desired functions, for example, to perform the corresponding steps of the point cloud coloring method according to the embodiment of the present invention, various application programs and various data may also be stored in the computer-readable storage medium, such as the application Various data used and/or generated by the program, etc.
  • the computer storage medium may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), and a portable compact disk. Read only memory (CD-ROM), USB memory, or any combination of the above storage media.
  • the computer-readable storage medium may be any combination of one or more computer-readable storage media.
  • a computer-readable storage medium contains program codes for adjusting the reflectivity of the point cloud.
  • each part of this application can be implemented by hardware, software, firmware, or a combination thereof.
  • multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system.
  • Discrete logic gate circuits with logic functions for data signals Logic circuits, dedicated integrated circuits with suitable combinational logic gate circuits, programmable gate array (Programmable Gate Array; hereinafter referred to as PGA), Field Programmable Gate Array (Field Programmable Gate Array; referred to as FPGA), etc.
  • the disclosed device and method may be implemented in other ways.
  • the device embodiments described above are only illustrative.
  • the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or It can be integrated into another device, or some features can be ignored or not implemented.
  • the various component embodiments of the present invention may be implemented by hardware, or by software modules running on one or more processors, or by a combination of them.
  • a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all of the functions of some modules according to the embodiments of the present invention.
  • DSP digital signal processor
  • the present invention can also be implemented as a device program (for example, a computer program and a computer program product) for executing part or all of the methods described herein.
  • Such a program for realizing the present invention may be stored on a computer-readable medium, or may have the form of one or more signals.
  • Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

Abstract

一种点云着色方法、点云着色系统和计算机存储介质，所述点云着色方法包括：获取点云数据，所述点云数据包括点云的位置信息和反射率信息；根据所述位置信息将所述点云分割为至少两个位置区间的点云；分别对每个位置区间中点云的反射率进行调整，以减小相同位置区间内至少部分点云的反射率的差异；根据经过所述调整后的反射率对所述点云进行着色。该点云着色方法、点云着色系统和计算机存储介质能够使得着色后的点云更接近实际场景，有助于后续的检测、分割等应用。

Description

点云着色方法、点云着色系统和计算机存储介质 技术领域
本发明涉及激光测距技术领域，具体而言涉及一种点云着色方法、点云着色系统和计算机存储介质。
背景技术
激光雷达(LiDAR)通过主动发射激光脉冲信号并获得其由被测物反射回来的脉冲信号来感知到周围物体的距离信息、位置信息、反射率信息等。其中，反射率信息可以提供关于被测物表面的重要信息，从而优化基于点云的分割、聚类、可视化等算法，在将扫描得到的三维点云进行空间显示时一般采用反射率对点云进行着色。
现有的激光雷达产品的着色方案大多是基于计算出的反射率或根据回波宽度进行着色，空间中物体表面的反射率越高或者回波宽度越宽，那么在进行着色时该点的颜色就越深。然而，在实际的应用中，这种点云着色方式会面临很多实际问题。首先，实际应用场景中的同一物体的同一表面会受到表面脏污或凹凸不平的影响而导致计算得到的反射率不同；其次，在进行反射率的计算过程中，由于只考虑到回光脉宽以及距离两个因素，没有考虑到实际的激光入射角度等因素，导致反射率计算不准确。因此，仅采用反射率进行着色的方案会对后续的视觉观感以及后续的检测分割等操作造成很大的影响。
发明内容
在发明内容部分中引入了一系列简化形式的概念，这将在具体实施方式部分中进一步详细说明。本发明的发明内容部分并不意味着要试图限定出所要求保护的技术方案的关键特征和必要技术特征，更不意味着试图确定所要求保护的技术方案的保护范围。
针对现有技术的不足，本发明实施例第一方面提供一种点云着色方法，所述点云着色方法包括：
获取点云数据，所述点云数据包括点云的位置信息和反射率信息；
根据所述位置信息将所述点云分割为至少两个位置区间的点云；
分别对每个位置区间中点云的反射率进行调整，以减小相同位置区间内至少部分点云的反射率的差异；
根据经过所述调整后的反射率对所述点云进行着色。
本发明实施例第二方面提供一种点云着色系统，所述点云着色系统包括：
存储器，用于存储可执行指令；
处理器，用于执行所述存储器中存储的所述指令，使得所述处理器执行以下步骤：
获取点云数据，所述点云数据包括点云的位置信息和反射率信息；
根据所述位置信息将所述点云分割为至少两个位置区间的点云；
分别对每个位置区间中点云的反射率进行调整，以减小相同位置区间内至少部分点云的反射率的差异；
根据经过所述调整后的反射率对所述点云进行着色。
本发明实施例第三方面提供一种计算机存储介质，其上存储有计算机程序，所述程序被处理器执行时实现本发明实施例第一方面提供的点云着色方法。
本发明实施例的点云着色方法、点云着色系统和计算机存储介质能够使得点云在显示的过程中着色更加均匀，更接近实际场景。
附图说明
为了更清楚地说明本发明实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。
图1示出了本发明一实施例中的测距装置的架构框图；
图2示出了本发明一实施例中的测距装置的结构示意图；
图3示出了根据本发明一个实施例的点云着色方法的示意性流程图；
图4示出了根据本发明一个实施例的点云着色系统的结构框图。
具体实施方式
为了使得本发明的目的、技术方案和优点更为明显，下面将参照附图详细描述根据本发明的示例实施例。显然，所描述的实施例仅仅是本发明的一部分实施例，而不是本发明的全部实施例，应理解，本发明不受这里描述的 示例实施例的限制。基于本发明中描述的本发明实施例，本领域技术人员在没有付出创造性劳动的情况下所得到的所有其它实施例都应落入本发明的保护范围之内。
在下文的描述中，给出了大量具体的细节以便提供对本发明更为彻底的理解。然而，对于本领域技术人员而言显而易见的是，本发明可以无需一个或多个这些细节而得以实施。在其他的例子中，为了避免与本发明发生混淆，对于本领域公知的一些技术特征未进行描述。
应当理解的是，本发明能够以不同形式实施，而不应当解释为局限于这里提出的实施例。相反地，提供这些实施例将使公开彻底和完全，并且将本发明的范围完全地传递给本领域技术人员。
在此使用的术语的目的仅在于描述具体实施例并且不作为本发明的限制。在此使用时，单数形式的“一”、“一个”和“所述/该”也意图包括复数形式，除非上下文清楚指出另外的方式。还应明白术语“组成”和/或“包括”，当在该说明书中使用时，确定所述特征、整数、步骤、操作、元件和/或部件的存在，但不排除一个或更多其它的特征、整数、步骤、操作、元件、部件和/或组的存在或添加。在此使用时，术语“和/或”包括相关所列项目的任何及所有组合。
为了彻底理解本发明，将在下列的描述中提出详细的结构，以便阐释本发明提出的技术方案。本发明的可选实施例详细描述如下，然而除了这些详细描述外，本发明还可以具有其他实施方式。
首先参考图1和图2对本发明实施例所涉及的一种测距装置的结构做详细的示例性地描述。所述测距装置可以包括激光雷达，该测距装置仅作为示例，对于其他适合的测距装置也可以应用于本申请。
测距装置用于感测外部环境信息，例如，环境目标的距离信息、方位信息、反射强度信息、速度信息等。一种实现方式中，测距装置可以通过测量测距装置和被测物之间光传播的时间，即光飞行时间(Time-of-Flight，TOF)，来探测被测物到测距装置的距离。或者，测距装置也可以通过其他技术来探测被测物到测距装置的距离，例如基于相位移动(phase shift)测量的测距方法，或者基于频率移动(frequency shift)测量的测距方法等，在此不做限制。
为了便于理解，以下将结合图1所示的测距装置100对测距的工作流程进行举例描述。
作为示例，测距装置100包括发射模块、扫描模块和探测模块，发射模块用于发射光脉冲序列，以探测目标场景；扫描模块用于将所述发射模块发 射的光脉冲序列的传播路径依次改变至不同方向出射，形成一个扫描视场；探测模块用于接收经物体反射回的光脉冲序列，以及根据所述反射回的光脉冲序列确定所述物体相对所述测距装置的距离和/或方位，以生成所述点云点。
具体地，如图1所示，发射模块包括发射电路110；探测模块包括接收电路120、采样电路130和运算电路140。
发射电路110可以出射光脉冲序列(例如激光脉冲序列)。接收电路120可以接收经过被探测物反射的光脉冲序列，也即通过其获得回波信号的脉冲波形，并对该光脉冲序列进行光电转换，以得到电信号，再对电信号进行处理之后可以输出给采样电路130。采样电路130可以对电信号进行采样，以获取采样结果。运算电路140可以基于采样电路130的采样结果，以确定测距装置100与被探测物之间的距离，也即深度。
可选地，该测距装置100还可以包括控制电路150，该控制电路150可以实现对其他电路的控制，例如，可以控制各个电路的工作时间和/或对各个电路进行参数设置等。
应理解，虽然图1示出的测距装置中包括一个发射电路、一个接收电路、一个采样电路和一个运算电路，用于出射一路光束进行探测，但是本申请实施例并不限于此，发射电路、接收电路、采样电路、运算电路中的任一种电路的数量也可以是至少两个，用于沿相同方向或分别沿不同方向出射至少两路光束；其中，该至少两束光路可以是同时出射，也可以是分别在不同时刻出射。一个示例中，该至少两个发射电路中的发光芯片封装在同一个模块中。例如，每个发射电路包括一个激光发射芯片，该至少两个发射电路中的激光发射芯片中的die封装到一起，容置在同一个封装空间中。
一些实现方式中，除了图1所示的电路，测距装置100还可以包括扫描模块，用于将发射电路出射的至少一路光脉冲序列(例如激光脉冲序列)改变传播方向出射，以对视场进行扫描。示例性地，所述扫描模块在测距装置的视场内的扫描区域随着时间的累积而增加。
其中，可以将包括发射电路110、接收电路120、采样电路130和运算电路140的模块，或者，包括发射电路110、接收电路120、采样电路130、运算电路140和控制电路150的模块称为测距模块，该测距模块可以独立于其他模块，例如，扫描模块。
测距装置中可以采用同轴光路，也即测距装置出射的光束和经反射回来的光束在测距装置内共用至少部分光路。例如，发射电路出射的至少一路激 光脉冲序列经扫描模块改变传播方向出射后，经探测物反射回来的激光脉冲序列经过扫描模块后入射至接收电路。或者，测距装置也可以采用异轴光路，也即测距装置出射的光束和经反射回来的光束在测距装置内分别沿不同的光路传输。图2示出了本发明的测距装置采用同轴光路的一种实施例的示意图。
测距装置200包括测距模块210，测距模块210包括发射器203(可以包括上述的发射电路)、准直元件204、探测器205(可以包括上述的接收电路、采样电路和运算电路)和光路改变元件206。测距模块210用于发射光束，且接收回光，将回光转换为电信号。其中，发射器203可以用于发射光脉冲序列。在一个实施例中，发射器203可以发射激光脉冲序列。可选的，发射器203发射出的激光束为波长在可见光范围之外的窄带宽光束。准直元件204设置于发射器的出射光路上，用于准直从发射器203发出的光束，将发射器203发出的光束准直为平行光出射至扫描模块。准直元件还用于会聚经探测物反射的回光的至少一部分。该准直元件204可以是准直透镜或者是其他能够准直光束的元件。
在图2所示实施例中，通过光路改变元件206来将测距装置内的发射光路和接收光路在准直元件204之前合并，使得发射光路和接收光路可以共用同一个准直元件，使得光路更加紧凑。在其他的一些实现方式中，也可以是发射器203和探测器205分别使用各自的准直元件，将光路改变元件206设置在准直元件之后的光路上。
在图2所示实施例中，由于发射器203出射的光束的光束孔径较小，测距装置所接收到的回光的光束孔径较大，所以光路改变元件可以采用小面积的反射镜来将发射光路和接收光路合并。在其他的一些实现方式中，光路改变元件也可以采用带通孔的反射镜，其中该通孔用于透射发射器203的出射光，反射镜用于将回光反射至探测器205。这样可以减小采用小反射镜的情况中小反射镜的支架会对回光的遮挡。
在图2所示实施例中，光路改变元件偏离了准直元件204的光轴。在其他的一些实现方式中，光路改变元件也可以位于准直元件204的光轴上。
测距装置200还包括扫描模块202。扫描模块202放置于测距模块210的出射光路上，扫描模块202用于改变经准直元件204出射的准直光束219的传输方向并投射至外界环境，并将回光投射至准直元件204。回光经准直元件204汇聚到探测器205上。
在一个实施例中，扫描模块202可以包括至少一个光学元件，用于改变 光束的传播路径，其中，该光学元件可以通过对光束进行反射、折射、衍射等等方式来改变光束传播路径，例如所述光学元件包括至少一个具有非平行的出射面和入射面的光折射元件。例如，扫描模块202包括透镜、反射镜、棱镜、振镜、光栅、液晶、光学相控阵(Optical Phased Array)或上述光学元件的任意组合。一个示例中，至少部分光学元件是运动的，例如通过驱动模块来驱动该至少部分光学元件进行运动，该运动的光学元件可以在不同时刻将光束反射、折射或衍射至不同的方向。在一些实施例中，扫描模块202的多个光学元件可以绕共同的轴209旋转或振动，每个旋转或振动的光学元件用于不断改变入射光束的传播方向。在一个实施例中，扫描模块202的多个光学元件可以以不同的转速旋转，或以不同的速度振动。在另一个实施例中，扫描模块202的至少部分光学元件可以以基本相同的转速旋转。在一些实施例中，扫描模块的多个光学元件也可以是绕不同的轴旋转。在一些实施例中，扫描模块的多个光学元件也可以是以相同的方向旋转，或以不同的方向旋转；或者沿相同的方向振动，或者沿不同的方向振动，在此不作限制。
在一个实施例中，扫描模块202包括第一光学元件214和与第一光学元件214连接的驱动器216，驱动器216用于驱动第一光学元件214绕转动轴209转动，使第一光学元件214改变准直光束219的方向。第一光学元件214将准直光束219投射至不同的方向。在一个实施例中，准直光束219经第一光学元件改变后的方向与转动轴209的夹角随着第一光学元件214的转动而变化。在一个实施例中，第一光学元件214包括相对的非平行的一对表面，准直光束219穿过该对表面。在一个实施例中，第一光学元件214包括厚度沿至少一个径向变化的棱镜。在一个实施例中，第一光学元件214包括楔角棱镜，对准直光束219进行折射。
在一个实施例中，扫描模块202还包括第二光学元件215，第二光学元件215绕转动轴209转动，第二光学元件215的转动速度与第一光学元件214的转动速度不同。第二光学元件215用于改变第一光学元件214投射的光束的方向。在一个实施例中，第二光学元件215与另一驱动器217连接，驱动器217驱动第二光学元件215转动。第一光学元件214和第二光学元件215可以由相同或不同的驱动器驱动，使第一光学元件214和第二光学元件215的转速和/或转向不同，从而将准直光束219投射至外界空间不同的方向，可以扫描较大的空间范围。在一个实施例中，控制器218控制驱动器216和217，分别驱动第一光学元件214和第二光学元件215。第一光学元件214和第二 光学元件215的转速可以根据实际应用中预期扫描的区域和样式确定。驱动器216和217可以包括电机或其他驱动器。
在一个实施例中，第二光学元件215包括相对的非平行的一对表面，光束穿过该对表面。在一个实施例中，第二光学元件215包括厚度沿至少一个径向变化的棱镜。在一个实施例中，第二光学元件215包括楔角棱镜。
一个实施例中，扫描模块202还包括第三光学元件(图未示)和用于驱动第三光学元件运动的驱动器。可选地，该第三光学元件包括相对的非平行的一对表面，光束穿过该对表面。在一个实施例中，第三光学元件包括厚度沿至少一个径向变化的棱镜。在一个实施例中，第三光学元件包括楔角棱镜。第一、第二和第三光学元件中的至少两个光学元件以不同的转速和/或转向转动。
在一个实施例中，所述扫描模块包括在所述光脉冲序列的出射光路上依次排布的2个或3个所述光折射元件。可选地，所述扫描模块中的至少2个所述光折射元件在扫描过程中旋转，以改变所述光脉冲序列的方向。
所述扫描模块在至少部分不同时刻的扫描路径不同，扫描模块202中的各光学元件旋转可以将光投射至不同的方向，例如投射的光211的方向和方向213，如此对测距装置200周围的空间进行扫描。当扫描模块202投射出的光211打到探测物201时，一部分光被探测物201沿与投射的光211相反的方向反射至测距装置200。探测物201反射的回光212经过扫描模块202后入射至准直元件204。
探测器205与发射器203放置于准直元件204的同一侧，探测器205用于将穿过准直元件204的至少部分回光转换为电信号。
一个实施例中，各光学元件上镀有增透膜。可选的，增透膜的厚度与发射器203发射出的光束的波长相等或接近，能够增加透射光束的强度。
一个实施例中，测距装置中位于光束传播路径上的一个元件表面上镀有滤光层，或者在光束传播路径上设置有滤光器，用于至少透射发射器所出射的光束所在波段，反射其他波段，以减少环境光给接收器带来的噪音。
在一些实施例中，发射器203可以包括激光二极管，通过激光二极管发射纳秒级别的激光脉冲。进一步地，可以确定激光脉冲接收时间，例如，通过探测电信号脉冲的上升沿时间和/或下降沿时间确定激光脉冲接收时间。如此，测距装置200可以利用脉冲接收时间信息和脉冲发出时间信息计算TOF，从而确定探测物201到测距装置200的距离。测距装置200探测到的距离和 方位可以用于遥感、避障、测绘、建模、导航等。
现有的测距装置在显示点云时通常基于反射率对点云进行着色。对于反射率的计算，通常根据预先标定的脉宽与回光能量的关系计算回光能量值，能量值再乘以距离的平方即为反射率。然而，事实上回光能量不仅与距离和反射率有关，还收到入射角度、激光光斑大小等的影响，而入射角度和激光光斑大小无法直接获得，因此在计算反射率时会引入一些随机误差。直接利用反射率进行点云着色会引入噪声，导致视觉效果差，且对后续的点云应用造成不良影响。
鉴于上述问题的存在，本发明实施例中提供一种点云着色方法，下面，首先参考附图3对本发明的点云着色方法进行描述。如图3所示，点云着色方法300包括以下步骤：
在步骤S310，获取点云数据，所述点云数据包括点云的位置信息和反射率信息；
在步骤S320，根据所述位置信息将所述点云分割为至少两个位置区间的点云；
在步骤S330，分别对每个位置区间中点云的反射率进行调整，以减小相同位置区间内至少部分点云的反射率的差异；
在步骤S340，根据经过所述调整后的反射率对所述点云进行着色。
本发明实施例的点云着色方法300能够减小相同位置区间内至少部分点云的反射率的差异，避免由于入射角度不同等原因导致的对同一物体测得的反射率不同的问题，使得点云在显示的过程中着色更加均匀，更接近实际场景，提高视觉效果，且有利于后续的检测、分割等应用。
示例性地，在步骤S310中，可以通过上述测距装置主动对被测物发射激光脉冲，捕捉激光回波信号并根据回波信号获取被测物的信息，例如根据激光发射和接收之间的时间差计算出被测物的距离，基于激光的已知发射方向，获得被测对象的角度信息等。通过高频率的发射和接收，可以获取海量的探测点的距离及角度信息等空间位置信息，称为点云，而探测点则可以称为点云点。
在一个实施例中，步骤S310中所获取的测距装置采集的原始点云数据包括脉冲宽度信息(即脉冲信号上升沿及下降沿达到某电压值的时间之差)和距离信息，点云数据中的反射率信息可以根据所述脉冲宽度信息和所述距离信息计算得到。
具体地，脉冲宽度信息用于计算反射信号的回光能量，回光能量与被测物的距离、反射率、入射角度、激光光斑大小等有关。由于入射角度和激光光斑大小无法直接获得，因而激光雷达接收的回光能量只考虑受到距离和反射率两个因素的影响，即认为回光能量与反射率成正比，与距离的平方成反比，如公式(1)所示：
E intensity＝k*r/R 2                        (1)
其中，E intensity为能量值，r为反射率，R为激光雷达与被测物的距离，k为与激光雷达相关的系数。
其中，对于回光能量的计算，可以预先由定点采集激光雷达在不同距离正入射时的数据，标定出脉冲宽度与回光能量的关系。在获取到点云数据中的脉冲宽度信息以后，可以根据预先标定的上述关系计算得到回光能量。除了脉冲宽度以外，也可以预先标定回光能量与回波高度、回波面积等特征的关系，并根据预先标定的上述特征与回光能量之间的关系计算回光能量。
作为示例，在标定脉冲宽度与能量关系的过程中，只考虑正入射，不考虑斜入射。在标定时，可以将激光雷达的转速设置为0，单点瞄准目标物，在不同距离(例如，10m内以0.5m为间隔，20m内以1m为间隔，20m外以2m为间隔)处由激光雷达向多个已知反射率真值的目标物发射光脉冲信号，接收目标物反射的反射脉冲信号，并对反射脉冲信号进行采样得到采样结果。之后，基于采样结果确定反射脉冲信号的脉冲宽度，基于每个目标物的反射率真值与每个目标物距离测距装置的距离真值的平方的比值得到回光能量，并基于脉冲宽度和回光能量拟合关系曲线，以得到脉冲宽度与回光能量的关系。其中，目标物可以为黑白泡棉或者其他材质的已知反射率真值的目标物。示例性地，为了提高标定的准确度和加快计算速度，在以上每种条件下都采用三次多项式分段拟合。
示例性地，在每次计算反射率之前，首先判断该脉冲宽度是否被展宽，被展宽的波形需要经过校正才能应用到脉冲宽度-回光能量曲线。对于被展宽的波形，可以以实际测量的脉冲宽度与以高度信息校正的脉冲宽度之差作为参数对其进行校正，根据测量所得的脉冲宽度和校正后的脉冲宽度来确定最终的输出脉冲宽度，并把输出的脉冲宽度限制在一个范围内。
根据上述脉冲宽度的选择与校正模型以及上述拟合所得的脉冲宽度与回光能量的关系，可以计算得出点云中不同点所在位置的回光能量值。再由计算得出的回光能量值与该点位置距离的平方相乘，即可得出该点所在位置的 反射率的值，如公式(2)所示：
r＝R 2/k*E intensity＝R 2/k*f(pulse_width)                 (2)
其中，pulse_width为回波的脉冲宽度。由此，反射率的计算转化为了距离与脉冲宽度的函数。
进一步地，例如激光雷达的测距装置在选材、生产、装备的过程中不可避免的会存在部分误差，而这些误差最终会体现在点云数据的深度、角度、反射率计算上，如表1所示：
表1
激光雷达序列号 黑色 灰色 绿色 白色
475 4.9 33.1 61.4 64.2
480 6.0 67.4 87.2 107.2
481 6.7 51.8 69 75.7
482 6.6 72.6 100.2 117.2
表1示出了不同的激光雷达在相同位置对不同反射率的材料进行测量得到的反射率值。由表1可以看出，不同激光雷达对同种颜色的材料测得的反射率相差较大，即不同设备间一致性较差。因此，在通过上文所述的方式得出反射率后，仍需对不同激光雷达的反射率进行进一步的个体差异一致性校正。在一致性校正时可以使用线性因子校正的方式，即使用针对激光雷达预先标定的线性因子对反射率进行校正，使反射率总体上更接近真实值，校正后的反射率如表2所示：
表2
激光雷达序列号 黑色 灰色 绿色 白色
475 7.0 47.5 88.1 92.1
480 4.3 48.4 62.3 76.6
481 6.9 53.6 71.3 78.3
482 4.7 51.2 70.7 82.7
由表2可以看出，在进行了个体差异一致性校正以后，降低了不同激光雷达测得的反射率之间的差异，且降低了与真实反射率之间的误差。
接着，在步骤S320中，根据点云数据中点云的位置信息将点云分割为至少两个位置区间的点云。其中，可以首先确定点云中的目标区域，并将目标区域分割为至少两个位置区间。或者，也可以不确定目标区域，而针对当前帧点云的整体进行位置区间的分割。目标区域可以根据应用需求来进行选择 例如对于行驶的车辆来说，目标区域可以是道路区域。
对位置区间的划分同样可以根据实际应用需求来进行设置。在一个实施例中，例如，针对路面场景来说，上述位置区间可以为地上区间和地面区间，地上区间中的点云为地上点，例如包括车辆、树木等的点云；地面区间中的点云为地面点。
其中，可以采用任意合适的方式分割出点云中的地上点和地面点。例如，可以首先从点云中分割出地面点，并将地面点以外的点云点认为是地上点。
作为示例，从点云中分割出地面点的步骤可以包括：首先，根据点云数据中点云点的高度确定出至少部分地面点；接着，对剩余的点云点进行平面拟合，并滤除与拟合所得的平面之间的距离大于阈值的点云点。之后，剩余的点云点则为所述地面点。
其中，确定至少部分地面点可以包括：首先，将点云空间的水平面栅格化，对于每一个栅格，以其中所有点云点的中高度最低的点云点的高度作为该栅格的参考高度，从而得到了点云空间的最小高度分布图；然后基于该最小高度分布图，设定一定的高度阈值，滤除每个栅格中与相应栅格的参考高度之间的高度差大于该阈值的点云点。之后，在此基础上，根据所有点云点在点云空间中的绝对高度，去除绝对高度大于某一阈值的点云点。之后保留的点云点即为地面点。确定出地面点之后，除地面点以外的点云点即为地上点。
应了解，本发明实施例不受具体采用的点云分割方法的限制，无论是现有的点云分割方法还是将来开发的点云分割方法，都可以应用于根据本发明实施例的点云着色方法中。
在步骤S330中，分别对每个位置区间中点云的反射率进行调整，以减小相同位置区间内至少部分点云的反射率的差异。通过减小相同位置区间内至少部分点云的反射率的差异，可以减少同一物体反射率不均匀的现象。
如上所述，当在点云中分割出的位置区间包括地上点和地面点时，步骤S330中进行的调整可以包括减小至少部分地上点的反射率的差异，以及减小至少部分地面点的反射率的差异。其中，减小相同位置区间内至少部分点云的反射率的差异具体可以包括减小相同位置区间内同一物体的点云的反射率的差异。
由于在进行反射率的计算和拟合时仅考虑到了正入射的方式，没有考虑到入射面的角度问题，因此在实际的应用中可能会受到物体表面的影响导致 的反射率计算偏差，例如在路面场景下，车辆的车身、路面的反射率、树木的反射率较为杂乱，噪声较多，影响视觉观感，并会对后续的基于反射率特征的检测、识别、分割等任务造成影响。根据本发明实施例，在对每个位置区间中点云的反射率进行调整以后，减小了相同位置区间内至少部分点云的反射率的差异，例如，在目标区域为道路区域时，所进行的调整减小了地面点之间的差异或地上点之间的差异，从而减小了由于入射角不同所导致的同一物体的点云反射率相差过大的问题，使处理后的点云的反射率更加均匀。
进一步地，对点云的反射率进行的调整还包括增大不同位置区间之间点云的反射率的差异。当在点云中分割出的位置区间包括地上点和地面点时，对点云反射率进行的调整包括增大地上点和地面点的反射率之间的差异。作为示例，减小相同位置区间内点云的反射率的差异、增大不同位置区间之间点云的反射率的差异包括但不限于将不同位置区间的点云的反射率分别按照不同的趋向进行归一化处理。通过增大不同位置区间之间的反射率的差异，可以使得后续利用反射率对点云进行着色时，不同位置区间的点云区别更加明显。
进一步地，对于每个位置区间，还可以将其分割为多个子位置区间，并以子位置区间为单位对反射率进行进一步的调整，以缩小相同物体的点云的反射率的差异，扩大不同物体的点云的反射率的差异。
例如，对于地面点来说，可以将地面点分割为多个第一子位置区间的地面点，并分别对每个第一子位置区间中地面点的反射率进行调整。作为示例，第一子位置区间可以根据点云与产生点云的测距装置之间的距离进行分割。
具体地，可以将地面点分割为多个二维网格的地面点，每个第一子位置区间包括至少一个网格，即可以由每一个网格构成一个第一子位置区间，也可以由多个网格共同构成一个第一子位置区间。由于现实的地面并非规则的平面，因而可以将地面点映射到水平面上，并将水平面划分为多个二维网格，映射到每个二维网格中的地面点被划分为相应网格中的地面点。在水平面中划分的网格可以具有相同的形状和尺寸。
在道路场景下，地面点一般包括普通路面的地面点和车道线、斑马线等路面标识的地面点。则将地面点分割为多个第一子位置区间后，每个第一子位置区间内的点云可能只包括普通路面点、只包括路面标识点、或者既包括普通路面点又包括路面标识点。本发明实施例对多个第一子位置区间的地面点的反射率进行的调整，以减小普通路面点与路面标识点内部反射率之间的 差异，并使普通路面点与路面标识点之间的区别更加明显。
为了实现增加不同表面的地面点的反射率之间的差异、减小相同表面的地面点的反射率之间的差异，可以对每个第一子位置区间中地面点的反射率进行如下调整：
当第一子位置区间中地面点的反射率之间的差异不超过预设阈值时，认为该第一子位置区间中包括相同表面的地面点，例如只包括普通路面点或只包括路面标识点，因而按照相同趋向调整该第一子位置区间中地面点的反射率。例如，可以将该第一子位置区间内所有地面点的反射率趋向于该第一子位置区间内反射率的较大的数值区间或较小的数值区间进行调整。此时可以综合多个第一子位置区间进行判断调整方向，当判断该第一子位置区间的反射率较大时，可以趋向较大的数值区间对反射率进行调整；当判断该第一子位置区间的反射率较小时，可以趋向较小的数值区间对反射率进行调整。
相应地，当第一子位置区间中的地面点的反射率之间的差异超过预设阈值时，认为该第一子位置区间中包括不同表面的地面点，例如既包括普通路面点又包括路面标识点，因而按照不同趋向调整所述第一子位置区间中地面点的反射率，以扩大不同表面反射率的区别，同时还能够减小相同表面反射率的区别。具体地，可以分别趋向于该第一子位置区间中地面点的反射率位于两端的两个数值区间调整该第一子位置区间中地面点的反射率。
例如，假设该第一子位置区间中既包括普通路面的地面点、又包括路标标识的地面点，其中普通路面的反射率较小，路标标识线的反射率较大，二者之间的差异超过预设阈值，此时将该第一子位置区间中反射率较小的地面点(即普通路面的地面点)的反射率均朝向该第一子位置区间中反射率最小的数值区间进行趋同调整，从而降低普通路面的地面点的反射率之间的差异；同时将该第一子位置区间中反射率较大的地面点(即路面标识的地面点)的反射率均朝向该第一子位置区间中反射率最大的数值区间进行趋同调整，从而降低路面标识的地面点的反射率之间的差异；此外，在分别向位于两端的数值区间进行趋同调整以后，显然也增大了普通路面的地面点与路面标识的地面点之间的差异。
此外，在一些实施例中，还可以对不同第一子位置区间中地面点的反射率的上述较大的数值区间进行趋同调整，以及对不同第一子位置区间中地面点的反射率的上述较小的数值区间进行趋同调整，以使不同第一子位置区间的反射率更为均匀。例如，根据以上描述，对于普通路面的地面点和路面标 识的地面点，在每个第一子位置区间中，无论该第一子位置区间中包括同种地面点或不同地面点，均将普通路面的地面点反射率的较小的数值区间进行调整，将路面标识的地面点的反射率超较大的数值区间进行调整。因而经过上述调整，可以减小不同第一子位置区间之间普通路面点内部和路面标识点内部的差异。
对于地上点来说，可以将其分割为至少两个第二子位置区间的地上点，并分别对每个第二子位置区间中的地上点的反射率进行调整。
作为示例，由于地上点中不同类别的物体一般分布于不同的高度区间，因而可以按照高度对地上点进行划分。具体地，可以以地面点所在的平面为基准，根据地上点在地面点所在的平面以上的高度将地上点分割为至少两个第二子位置区间的地上点。例如，当应用于自动驾驶时，由于路面场景下较为关注的车辆的高度一般分布在路面上方的一定高度范围内，而对高于此高度范围的物体的关注度较低，因而可以将地面点所在的平面以上第一高度内的地上点确定为第一第二子位置区间的地上点，将所述地面点所在的平面以上第一高度至第二高度之间的地上点确定为第二第二子位置区间的地上点。例如，第一第二子位置区间的高度范围可以为0-2米，第二第二子位置区间的高度范围可以为2-5米。地上点的高度区间可以根据需要进行合理的设置，在此不对其进行具体限定。当然，地上点还可以包括多于两个的高度区间，在此不做具体限定。
对第二子位置区间的反射率进行的调整可以包括缩小相同第二子位置区间内地上点的反射率的差异，扩大不同第二子位置区间内地上点的反射率的差异。例如，第一第二子位置区间内的地上点一般包括车辆的点云，第二第二子位置区间内的地上点一般包括道路两旁的树木的点云，因而上述调整可以缩小车辆的点云内部和树木的点云内部的差异，扩大车辆的点云与树木的点云之间的差异。在一些实施例中，也可以对第二子位置区间的反射率进行的调整可以类似于上文中对第一子位置区间的反射率进行的调整，例如可以划分多个第二子位置区间，分别判断每个第二子位置区间内包括相同物体的点云或不同物体的点云，并减小相同物体的点云之间的差异，扩大不同物体的点云之间的差异。
此外，由于测距装置的出射光在被测物表面的入射角还受到被测物在视场中的位置的影响，例如路面近处的入射角较小，远处的入射角相对较大，靠近视场中心区域的入射角较小，靠近视场边缘区域的入射角较大；对于同 一个建筑物，较低位置处入射角较小，较高位置处入射角较大。入射角不同将影响回光能量，进而影响根据回光能量测得的反射率。因而在一个实施例中，点云着色方法300还可以包括：根据点云数据中的位置信息确定调整系数，并使用所述调整系数对所述点云的反射率进行调整，其中，至少两个不同位置处的点云的调整系数不同。其中，所述位置信息包括以下至少一项：距离信息，高度信息，在当前视场中的水平位置信息。
具体地，调整系数可以随位置信息的变化而变化，例如，可以随着距离、高度或水平位置信息的变化而呈梯度变化或线性变化。可以根据不同的位置信息确定多个调整系数，并执行多次调整。采用与距离信息相关的调整系数对反射率进行的调整可以在执行步骤S330所述的调整之前或之后进行。
以高度为例，不同高度下可以按照如下公式(3)对点云的反射率进行归一化调整：
Figure PCTCN2020091091-appb-000001
其中r是归一化之前解算出的反射率值，point.z为当前点的高度值，z max和z_min分别指的是当前帧的点云高度最大值和最小值，R为高度归一化之后的反射率值。
在步骤S340，根据经过上述调整后的反射率对点云进行着色。
示例性地，对于每一个点云点来说，若检测到该点的反射率属于某一预设的反射率区间，则将该反射率区间所对应的像素参数赋予该点云点。
其中，每个反射率区间所对应的像素参数可以包括像素颜色和像素灰度中的至少一项。示例性的，像素颜色可以采用三通道色值表示，不同的像素颜色对应的三通道色值不同。若某个点云点属于某一反射率区间，则将该反射率区间对应的三通道色值赋予该点云点，使得该点云点显示的颜色为该三通道色值对应的颜色。由于不同的被测物具有不同的反射率，则不同的被测物会显示为不同的颜色。
在未对点云的反射率进行调整之前，由于点云反射率计算过程中的随机误差以及雷达设备生产过程中的不一致性导致同一物体的不同位置所测得的反射率不同，在进行识别和分割时会导致识别及分割的结果由于受到反射率的影响而产生错误。
而根据本发明实施例的点云着色方法300，可以使得反射率的分布在整个空间中变得均匀，使得场景中的相同物体的反射率更加一致，不同物体对比更加的明显，更加有利于检测、分割等算法稳定性及准确性的提升。
下面，参考图4对本发明一个实施例的点云着色系统做描述，其中，前述测距装置的特征可以结合到本实施例中。所述点云着色系统可实现为计算机、服务器或车载终端等电子设备。
在一些实施例中，如图4所述的点云着色系统400还包括一个或多个处理器410，一个或多个存储器420，一个或多个处理器410共同地或单独地工作。可选地，点云着色系统400还可以包括输入装置(未示出)、输出装置(未示出)以及图像传感器(未示出)中的至少一个，这些组件通过总线系统和/或其它形式的连接机构(未示出)互连。
存储器420用于存储处理器可执行的程序指令，例如用于存储用于实现根据本发明实施例的点云着色方法的相应步骤和程序指令。可以包括一个或多个计算机程序产品，所述计算机程序产品可以包括各种形式的计算机可读存储介质，例如易失性存储器和/或非易失性存储器。所述易失性存储器例如可以包括随机存取存储器(RAM)和/或高速缓冲存储器(cache)等。所述非易失性存储器例如可以包括只读存储器(ROM)、硬盘、闪存等。
所述输入装置可以是用户用来输入指令的装置，并且可以包括键盘、鼠标、麦克风和触摸屏等中的一个或多个。
所述输出装置可以向外部(例如用户)输出各种信息(例如图像或声音)，并且可以包括显示器、扬声器等中的一个或多个，用于将着色后的点云输出为图像或视频。
通信接口(未示出)用于与其他设备之间进行通信，包括有线或者无线方式的通信。测距装置可以接入基于通信标准的无线网络，如WiFi、2G、3G、4G、5G或它们的组合。在一个示例性实施例中，通信接口经由广播信道接收来自外部广播管理系统的广播信号或广播相关信息。在一个示例性实施例中，所述通信接口还包括近场通信(NFC)模块，以促进短程通信。例如，在NFC模块可基于射频识别(RFID)技术，红外数据协会(IrDA)技术，超宽带(UWB)技术，蓝牙(BT)技术和其他技术来实现。
处理器410可以是中央处理单元(CPU)、图像处理单元(GPU)、专用集成电路(ASIC)、现场可编程门阵列(FPGA)或者具有数据处理能力和/或指令执行能力的其它形式的处理单元，并且可以控制点云着色系统中的其它组件以执行期望的功能。所述处理器能够执行所述存储器中存储的指令，以执行本文描述的本发明实施例的点云着色方法，该些方法参考前述实施例 中的描述，在此不再重复赘述。例如，处理器能够包括一个或多个嵌入式处理器、处理器核心、微型处理器、逻辑电路、硬件有限状态机(FSM)、数字信号处理器(DSP)或它们的组合。在本实施例中，所述处理器包括现场可编程门阵列(FPGA)，其中，测距装置的运算电路可以是现场可编程门阵列(FPGA)的一部分。
所述点云着色系统400包括一个或多个处理器，共同地或单独地工作，存储器用于存储程序指令；所述处理器用于执行所述存储器存储的程序指令，当所述程序指令被执行时，所述处理器用于实现根据本发明实施例的点云着色方法中的相应步骤，为避免重复，对该些方法的具体描述可以参考前述实施例的相关描述。
在一种实施方式中，本发明实施方式的点云着色系统可应用于可移动平台。具有点云着色系统的可移动平台可对外部环境进行测量，例如，测量移动平台与障碍物的距离用于避障等用途，和对外部环境进行二维或三维的测绘。在某些实施方式中，可移动平台包括无人驾驶车辆或安装有高级驾驶辅助系统(Advanced Driving Assistance System，ADAS)的车辆。可移动平台还可以包括无人飞行器、机器人、船、相机中的至少一种。
本发明实施例中的点云着色系统由于用于执行前述的方法，而移动平台包括该点云着色系统，因此点云着色系统和移动平台均具有和前述方法相同的优点。
另外，本发明实施例还提供了一种计算机存储介质，其上存储有计算机程序。在所述计算机可读存储介质上可以存储一个或多个计算机程序指令，处理器可以运行存储器存储的所述程序指令，以实现本文所述的本发明实施例中(由处理器实现)的功能以及/或者其它期望的功能，例如以执行根据本发明实施例的点云着色方法的相应步骤，在所述计算机可读存储介质中还可以存储各种应用程序和各种数据，例如所述应用程序使用和/或产生的各种数据等。
例如，所述计算机存储介质例如可以包括智能电话的存储卡、平板电脑的存储部件、个人计算机的硬盘、只读存储器(ROM)、可擦除可编程只读存储器(EPROM)、便携式紧致盘只读存储器(CD-ROM)、USB存储器、或者上述存储介质的任意组合。所述计算机可读存储介质可以是一个或多个计算机可读存储介质的任意组合。例如一个计算机可读存储介质包含用于对点云的反射率进行调整的程序代码等。
应当理解，本申请的各部分可以用硬件、软件、固件或它们的组合来实现。在上述实施方式中，多个步骤或方法可以用存储在存储器中且由合适的指令执行系统执行的软件或固件来实现。如，如果用硬件来实现和在另一实施方式中一样，可用本领域公知的下列技术中的任一项或他们的组合来实现：具有用于对数据信号实现逻辑功能的逻辑门电路的离散逻辑电路，具有合适的组合逻辑门电路的专用集成电路，可编程门阵列(Programmable Gate Array；以下简称：PGA)，现场可编程门阵列(Field Programmable Gate Array；简称：FPGA)等。
尽管这里已经参考附图描述了示例实施例，应理解上述示例实施例仅仅是示例性的，并且不意图将本发明的范围限制于此。本领域普通技术人员可以在其中进行各种改变和修改，而不偏离本发明的范围和精神。所有这些改变和修改意在被包括在所附权利要求所要求的本发明的范围之内。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本发明的范围。
在本申请所提供的几个实施例中，应该理解到，所揭露的设备和方法，可以通过其它的方式实现。例如，以上所描述的设备实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个设备，或一些特征可以忽略，或不执行。
在此处所提供的说明书中，说明了大量具体细节。然而，能够理解，本发明的实施例可以在没有这些具体细节的情况下实践。在一些实例中，并未详细示出公知的方法、结构和技术，以便不模糊对本说明书的理解。
类似地，应当理解，为了精简本发明并帮助理解各个发明方面中的一个或多个，在对本发明的示例性实施例的描述中，本发明的各个特征有时被一起分组到单个实施例、图、或者对其的描述中。然而，并不应将该本发明的方法解释成反映如下意图：即所要求保护的本发明要求比在每个权利要求中所明确记载的特征更多的特征。更确切地说，如相应的权利要求书所反映的那样，其发明点在于可以用少于某个公开的单个实施例的所有特征的特征来解决相应的技术问题。因此，遵循具体实施方式的权利要求书由此明确地并 入该具体实施方式，其中每个权利要求本身都作为本发明的单独实施例。
本领域的技术人员可以理解，除了特征之间相互排斥之外，可以采用任何组合对本说明书(包括伴随的权利要求、摘要和附图)中公开的所有特征以及如此公开的任何方法或者设备的所有过程或单元进行组合。除非另外明确陈述，本说明书(包括伴随的权利要求、摘要和附图)中公开的每个特征可以由提供相同、等同或相似目的替代特征来代替。
此外，本领域的技术人员能够理解，尽管在此所述的一些实施例包括其它实施例中所包括的某些特征而不是其它特征，但是不同实施例的特征的组合意味着处于本发明的范围之内并且形成不同的实施例。例如，在权利要求书中，所要求保护的实施例的任意之一都可以以任意的组合方式来使用。
本发明的各个部件实施例可以以硬件实现，或者以在一个或者多个处理器上运行的软件模块实现，或者以它们的组合实现。本领域的技术人员应当理解，可以在实践中使用微处理器或者数字信号处理器(DSP)来实现根据本发明实施例的一些模块的一些或者全部功能。本发明还可以实现为用于执行这里所描述的方法的一部分或者全部的装置程序(例如，计算机程序和计算机程序产品)。这样的实现本发明的程序可以存储在计算机可读介质上，或者可以具有一个或者多个信号的形式。这样的信号可以从因特网网站上下载得到，或者在载体信号上提供，或者以任何其他形式提供。
应该注意的是上述实施例对本发明进行说明而不是对本发明进行限制，并且本领域技术人员在不脱离所附权利要求的范围的情况下可设计出替换实施例。在权利要求中，不应将位于括号之间的任何参考符号构造成对权利要求的限制。本发明可以借助于包括有若干不同元件的硬件以及借助于适当编程的计算机来实现。在列举了若干装置的单元权利要求中，这些装置中的若干个可以是通过同一个硬件项来具体体现。单词第一、第二、以及第三等的使用不表示任何顺序。可将这些单词解释为名称。

Claims (37)

  1. 一种点云着色方法，其特征在于，所述方法包括：
    获取点云数据，所述点云数据包括点云的位置信息和反射率信息；
    根据所述位置信息将所述点云分割为至少两个位置区间的点云；
    分别对每个位置区间中点云的反射率进行调整，以减小相同位置区间内至少部分点云的反射率的差异；
    根据经过所述调整后的反射率对所述点云进行着色。
  2. 根据权利要求1所述的方法，其特征在于，所述调整还包括增大不同位置区间之间点云的反射率的差异。
  3. 根据权利要求1所述的方法，其特征在于，所述根据所述位置信息将所述点云分割为至少两个位置区间的点云，包括：
    确定位于目标区域中的点云，并将所述目标区域中的点云分割为至少两个位置区间的点云。
  4. 根据权利要求3所述的方法，其特征在于，所述目标区域包括道路区域。
  5. 根据权利要求1或2所述的方法，其特征在于，所述根据所述位置信息将所述点云分割为至少两个位置区间的点云，包括：从所述点云中分割出地面点和地上点，
    所述对每个位置区间中点云的反射率进行调整包括：扩大所述地面点的反射率与所述地上点的反射率之间的差异。
  6. 根据权利要求3所述的方法，其特征在于，所述分别对每个位置区间中点云的反射率进行调整还包括：
    将所述地面点分割为多个第一子位置区间的地面点；
    分别对每个所述第一子位置区间中地面点的反射率进行调整。
  7. 根据权利要求6所述的方法，其特征在于，所述第一子位置区间根据点云与产生所述点云的测距装置之间的距离进行分割。
  8. 根据权利要求6所述的方法，其特征在于，所述将所述地面点分割为多个第一子位置区间的地面点包括：将所述地面点分割为多个二维网格的地面点。
  9. 根据权利要求8所述的方法，其特征在于，每个所述第一子位置区间包括至少一个网格。
  10. 根据权利要求6-9之一所述的方法，其特征在于，所述分别对每个 所述第一子位置区间中地面点的反射率进行调整，包括：
    当所述第一子位置区间中地面点的反射率之间的差异不超过预设阈值时，按照相同趋向调整所述第一子位置区间中地面点的反射率；和/或，
    当所述第一子位置区间中的地面点的反射率之间的差异超过预设阈值时，按照不同趋向调整所述第一子位置区间中地面点的反射率。
  11. 根据权利要求10所述的方法，其特征在于，所述按照不同趋向调整所述第一子位置区间中地面点的反射率，包括：
    分别趋向于所述第一子位置区间中地面点的反射率位于两端的两个数值区间调整该第一子位置区间中地面点的反射率。
  12. 根据权利要求11所述的方法，其特征在于，所述分别对每个所述第一子位置区间中地面点的反射率进行调整，还包括：
    对不同第一子位置区间中地面点的反射率的较大的所述数值区间进行趋同调整，以及对不同第一子位置区间中地面点的反射率的较小的所述数值区间进行趋同调整。
  13. 根据权利要求5所述的方法，其特征在于，所述分别对每个位置区间中点云的反射率进行调整还包括：
    将所述地上点分割为至少两个第二子位置区间的地上点；
    对每个所述第二子位置区间中的地上点的反射率进行调整，以缩小相同第二子位置区间内地上点的反射率的差异，和/或，扩大不同第二子位置区间之间地上点的反射率的差异。
  14. 根据权利要求13所述的方法，其特征在于，所述将所述地上点分割为至少两个第二子位置区间的地上点，包括：
    以所述地面点所在的平面为基准，根据所述地上点在所述地面点所在的平面以上的高度将所述地上点分割为至少两个第二子位置区间的地上点。
  15. 根据权利要求14所述的方法，其特征在于，所述根据所述地上点在所述地面点所在的平面以上的高度将所述地上点分割为至少两个第二子位置区间的地上点，包括：
    将所述地面点所在的平面以上第一高度内的地上点确定为第一第二子位置区间的地上点，将所述地面点所在的平面以上第一高度至第二高度之间的地上点确定为第二第二子位置区间的地上点。
  16. 根据权利要求1所述的方法，其特征在于，所述方法还包括：
    根据所述位置信息确定调整系数，并使用所述调整系数对所述点云的反 射率进行调整，其中，至少两个不同位置处的点云的所述调整系数不同。
  17. 根据权利要求16所述的方法，其特征在于，所述位置信息包括以下至少一项：距离信息，高度信息，在当前视场中的水平位置信息。
  18. 根据权利要求1所述的方法，其特征在于，所述获取点云数据包括：
    获取测距装置采集的原始点云数据，所述原始点云数据包括脉冲宽度信息和距离信息；
    根据所述脉冲宽度信息和所述距离信息计算得到所述反射率信息；
    根据预先标定的所述测距装置的校正因子对所述反射率信息进行校正。
  19. 一种点云着色系统，其特征在于，所述系统包括：
    存储器，用于存储可执行指令；
    处理器，用于执行所述存储器中存储的所述指令，使得所述处理器执行以下步骤：
    获取点云数据，所述点云数据包括点云的位置信息和反射率信息；
    根据所述位置信息将所述点云分割为至少两个位置区间的点云；
    分别对每个位置区间中点云的反射率进行调整，以减小相同位置区间内至少部分点云的反射率的差异；
    根据经过所述调整后的反射率对所述点云进行着色。
  20. 根据权利要求19所述的系统，其特征在于，所述调整还包括增大不同位置区间之间点云的反射率的差异。
  21. 根据权利要求19所述的系统，其特征在于，所述根据所述位置信息将所述点云分割为至少两个位置区间的点云，包括：
    确定位于目标区域中的点云，并将所述目标区域分割为至少两个位置区间的点云。
  22. 根据权利要求21所述的系统，其特征在于，所述目标区域包括道路区域。
  23. 根据权利要求19或20所述的系统，其特征在于，所述根据所述位置信息将所述点云分割为至少两个位置区间的点云，包括：从所述点云中分割出地面点和地上点，
    所述对点云的反射率进行调整包括：扩大所述地面点的反射率与所述地上点的反射率之间的差异。
  24. 根据权利要求21所述的系统，其特征在于，所述分别对每个位置区间中点云的反射率进行调整还包括：
    将所述地面点分割为多个第一子位置区间的地面点；
    分别对每个所述第一子位置区间中地面点的反射率进行调整。
  25. 根据权利要求24所述的系统，其特征在于，所述第一子位置区间根据点云与产生所述点云的测距装置之间的距离进行分割。
  26. 根据权利要求24所述的系统，其特征在于，所述将所述地面点分割为多个第一子位置区间的地面点包括：将所述地面点分割为多个二维网格的地面点。
  27. 根据权利要求26所述的系统，其特征在于，每个所述第一子位置区间包括至少一个网格。
  28. 根据权利要求24-27之一所述的系统，其特征在于，所述分别对每个所述第一子位置区间中地面点的反射率进行调整，包括：
    当所述第一子位置区间中地面点的反射率之间的差异不超过预设阈值时，按照相同趋向调整所述第一子位置区间中地面点的反射率；和/或，
    当所述第一子位置区间中的地面点的反射率之间的差异超过预设阈值时，按照不同趋向调整所述第一子位置区间中地面点的反射率。
  29. 根据权利要求28所述的系统，其特征在于，所述按照不同趋向调整所述第一子位置区间中地面点的反射率，包括：
    分别趋向于所述第一子位置区间中地面点的反射率位于两端的两个数值区间调整该第一子位置区间中地面点的反射率。
  30. 根据权利要求29所述的系统，其特征在于，所述分别对每个所述第一子位置区间中地面点的反射率进行调整，还包括：
    对不同第一子位置区间中地面点的反射率的较大的所述数值区间进行趋同调整，以及对不同第一子位置区间中地面点的反射率的较小的所述数值区间进行趋同调整。
  31. 根据权利要求23所述的系统，其特征在于，所述分别对每个位置区间中点云的反射率进行调整还包括：
    将所述地上点分割为至少两个第二子位置区间的地上点；
    对每个所述第二子位置区间中的地上点的反射率进行调整，以缩小相同第二子位置区间内地上点的反射率的差异，和/或，扩大不同第二子位置区间之间地上点的反射率的差异。
  32. 根据权利要求31所述的系统，其特征在于，所述将所述地上点分割为至少两个第二子位置区间的地上点，包括：
    以所述地面点所在的平面为基准，根据所述地上点在所述地面点所在的平面以上的高度将所述地上点分割为至少两个第二子位置区间的地上点。
  33. 根据权利要求32所述的系统，其特征在于，所述根据所述地上点在所述地面点所在的平面以上的高度将所述地上点分割为至少两个第二子位置区间的地上点，包括：
    将所述地面点所在的平面以上第一高度内的地上点确定为第一第二子位置区间的地上点，将所述地面点所在的平面以上第一高度至第二高度之间的地上点确定为第二第二子位置区间的地上点。
  34. 根据权利要求19所述的系统，其特征在于，所述处理器还用于：
    根据所述位置信息确定调整系数，并使用所述调整系数对所述点云的反射率进行调整，其中，至少两个不同位置处的点云的所述调整系数不同。
  35. 根据权利要求34所述的系统，其特征在于，所述位置信息包括以下至少一项：距离信息，高度信息，在当前视场中的水平位置信息。
  36. 根据权利要求19所述的系统，其特征在于，所述获取点云数据包括：
    获取测距装置采集的原始点云数据，所述原始点云数据包括脉冲宽度信息和距离信息；
    根据所述脉冲宽度信息和所述距离信息计算得到所述反射率信息；
    根据预先标定的所述测距装置的校正因子对所述反射率信息进行校正。
  37. 一种计算机存储介质，其上存储有计算机程序，其特征在于，所述程序被处理器执行时实现权利要求1至18中任一项所述的点云着色方法。
PCT/CN2020/091091 2020-05-19 2020-05-19 点云着色方法、点云着色系统和计算机存储介质 WO2021232247A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CN2020/091091 WO2021232247A1 (zh) 2020-05-19 2020-05-19 点云着色方法、点云着色系统和计算机存储介质
CN202080005200.XA CN114026410A (zh) 2020-05-19 2020-05-19 点云着色方法、点云着色系统和计算机存储介质

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2020/091091 WO2021232247A1 (zh) 2020-05-19 2020-05-19 点云着色方法、点云着色系统和计算机存储介质

Publications (1)

Publication Number Publication Date
WO2021232247A1 true WO2021232247A1 (zh) 2021-11-25

Family

ID=78709019

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/091091 WO2021232247A1 (zh) 2020-05-19 2020-05-19 点云着色方法、点云着色系统和计算机存储介质

Country Status (2)

Country Link
CN (1) CN114026410A (zh)
WO (1) WO2021232247A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114529652A (zh) * 2022-04-24 2022-05-24 深圳思谋信息科技有限公司 点云补偿方法、装置、设备、存储介质和计算机程序产品

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104374780A (zh) * 2014-12-04 2015-02-25 上海岩土工程勘察设计研究院有限公司 隧道内三维激光扫描反射率的校正方法
WO2016134321A1 (en) * 2015-02-20 2016-08-25 Apple Inc. Actuated optical element for light beam scanning device
CN107851176A (zh) * 2015-02-06 2018-03-27 阿克伦大学 光学成像系统及其方法
CN109506672A (zh) * 2017-09-15 2019-03-22 高德软件有限公司 一种路面标记激光点云的获取方法及装置
CN110132130A (zh) * 2019-03-05 2019-08-16 上海宾通智能科技有限公司 激光雷达位置标定方法、系统及其数据处理方法、系统

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6686921B1 (en) * 2000-08-01 2004-02-03 International Business Machines Corporation Method and apparatus for acquiring a set of consistent image maps to represent the color of the surface of an object
US11041957B2 (en) * 2018-06-25 2021-06-22 Toyota Motor Engineering & Manufacturing North America, Inc. Systems and methods for mitigating effects of high-reflectivity objects in LiDAR data
CN109191553B (zh) * 2018-08-29 2023-07-25 百度在线网络技术（北京）有限公司 点云渲染方法、装置、终端及存储介质
CN110031822B (zh) * 2019-04-22 2020-05-22 上海禾赛光电科技有限公司 可用于激光雷达的噪点识别方法以及激光雷达系统

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104374780A (zh) * 2014-12-04 2015-02-25 上海岩土工程勘察设计研究院有限公司 隧道内三维激光扫描反射率的校正方法
CN107851176A (zh) * 2015-02-06 2018-03-27 阿克伦大学 光学成像系统及其方法
WO2016134321A1 (en) * 2015-02-20 2016-08-25 Apple Inc. Actuated optical element for light beam scanning device
CN109506672A (zh) * 2017-09-15 2019-03-22 高德软件有限公司 一种路面标记激光点云的获取方法及装置
CN110132130A (zh) * 2019-03-05 2019-08-16 上海宾通智能科技有限公司 激光雷达位置标定方法、系统及其数据处理方法、系统

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114529652A (zh) * 2022-04-24 2022-05-24 深圳思谋信息科技有限公司 点云补偿方法、装置、设备、存储介质和计算机程序产品
CN114529652B (zh) * 2022-04-24 2022-07-19 深圳思谋信息科技有限公司 点云补偿方法、装置、设备和存储介质

Also Published As

Publication number Publication date
CN114026410A (zh) 2022-02-08

Similar Documents

Publication Publication Date Title
WO2022126427A1 (zh) 点云处理方法、点云处理装置、可移动平台和计算机存储介质
CN107861113B (zh) 标定方法及装置
WO2020243962A1 (zh) 物体检测方法、电子设备和可移动平台
WO2021051281A1 (zh) 点云滤噪的方法、测距装置、系统、存储介质和移动平台
WO2021189794A1 (zh) 飞行时间测距系统及其测距方法
WO2020177077A1 (zh) 一种标定板、深度参数标定方法、探测装置及标定系统
WO2021062581A1 (zh) 路面标识识别方法及装置
WO2022011974A1 (zh) 一种距离测量系统、方法及计算机可读存储介质
US20240103142A1 (en) Space measurement apparatus, method, and device, and computer-readable storage medium
WO2022198637A1 (zh) 点云滤噪方法、系统和可移动平台
WO2020215252A1 (zh) 测距装置点云滤噪的方法、测距装置和移动平台
WO2021232247A1 (zh) 点云着色方法、点云着色系统和计算机存储介质
CN108303702B (zh) 一种相位式激光测距系统及方法
CN110018491B (zh) 激光扫描方法、装置及激光雷达
WO2021232227A1 (zh) 构建点云帧的方法、目标检测方法、测距装置、可移动平台和存储介质
US20210255289A1 (en) Light detection method, light detection device, and mobile platform
CN115081240A (zh) 一种提升仿真激光雷达数据真实性的点云数据处理方法
WO2020237663A1 (zh) 一种多通道激光雷达点云插值的方法和测距装置
WO2020177076A1 (zh) 一种探测装置初始状态标定方法及装置
WO2020155159A1 (zh) 增加点云采样密度的方法、点云扫描系统、可读存储介质
WO2022256976A1 (zh) 稠密点云真值数据的构建方法、系统和电子设备
WO2022217520A1 (zh) 探测方法、装置、可移动平台及存储介质
CN115469331A (zh) Itof相机、标定方法及相关设备
WO2020107379A1 (zh) 应用于测距装置的反射率校正方法、测距装置
WO2021026766A1 (zh) 扫描模块的电机转速控制方法、装置和测距装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20936949

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20936949

Country of ref document: EP

Kind code of ref document: A1