image_to_world_planeT_image_to_world_planeImageToWorldPlaneImageToWorldPlaneimage_to_world_plane（算子）

名称

image_to_world_planeT_image_to_world_planeImageToWorldPlaneImageToWorldPlaneimage_to_world_plane — 通过将图像变换到世界坐标系的平面 z=0 来校正图像。

签名

描述

image_to_world_planeimage_to_world_planeImageToWorldPlaneImageToWorldPlaneImageToWorldPlaneimage_to_world_plane rectifies an image ImageImageImageImageimageimage by transforming it into the plane z=0 (plane of measurements) in a world coordinate system. The resulting rectified image ImageWorldImageWorldImageWorldImageWorldimageWorldimage_world shows neither radial nor perspective distortions; it corresponds to an image acquired by a distortion-free camera that looks perpendicularly onto the plane of measurements. The world coordinate system is chosen by passing its 3D pose relative to the camera coordinate system in WorldPoseWorldPoseWorldPoseWorldPoseworldPoseworld_pose. Hence, latter one is expected in the form , where ccs denotes the camera coordinate system and wcs the world coordinate system (see Transformations / Poses and “Solution Guide III-C - 3D Vision”). In CameraParamCameraParamCameraParamCameraParamcameraParamcamera_param you must pass the internal camera parameters (see 标定 for the sequence of the parameters and the underlying camera model).

In many cases CameraParamCameraParamCameraParamCameraParamcameraParamcamera_param and WorldPoseWorldPoseWorldPoseWorldPoseworldPoseworld_pose are the result of calibrating the camera with the operator calibrate_camerascalibrate_camerasCalibrateCamerasCalibrateCamerasCalibrateCamerascalibrate_cameras。See below for an example.

The pixel position of the upper left corner of the output image ImageWorldImageWorldImageWorldImageWorldimageWorldimage_world is determined by the origin of the world coordinate system. The size of the output image ImageWorldImageWorldImageWorldImageWorldimageWorldimage_world can be chosen by the parameters WidthWidthWidthWidthwidthwidth, HeightHeightHeightHeightheightheight, and ScaleScaleScaleScalescalescale. WidthWidthWidthWidthwidthwidth and HeightHeightHeightHeightheightheight must be given in pixels.

The parameter ScaleScaleScaleScalescalescale can be used to specify the size of a pixel in the transformed image. There are two ways to use this parameter:

Scale pixels to metric units：

Scale the image such that one pixel in the transformed image corresponds to a metric unit, e.g., setting 'mm'"mm""mm""mm""mm""mm" determines that a pixel in the transformed image corresponds to the area 1mm x 1mm in the plane of measurements. For this, the original unit needs to be meters. This is the case if you use a standard calibration plate.

值列表： 'm'"m""m""m""m""m", 'cm'"cm""cm""cm""cm""cm", 'mm'"mm""mm""mm""mm""mm", 'microns'"microns""microns""microns""microns""microns", 'um'"um""um""um""um""um".

Default: 'm'"m""m""m""m""m".

Control scaling manually：

Scale the image by giving a number that determines the ratio of original unit length / desired number of pixels. E.g., if your original unit is meters and you want every pixel of your transformed image to represent 3mm x 3mm of the measuring plane, your scale is calculated . If you want to perform a task like shape-based matching on your transformed image, it is useful to scale the image such that its content appears in a size similar to the original image.

Restriction: ScaleScaleScaleScalescalescale > 0.

The parameter InterpolationInterpolationInterpolationInterpolationinterpolationinterpolation specifies, whether bilinear interpolation ('bilinear'"bilinear""bilinear""bilinear""bilinear""bilinear") should be applied between the pixels in the input image or whether the gray value of the nearest neighboring pixel ('nearest_neighbor'"nearest_neighbor""nearest_neighbor""nearest_neighbor""nearest_neighbor""nearest_neighbor") should be used.

If several images have to be rectified using the same parameters, gen_image_to_world_plane_mapgen_image_to_world_plane_mapGenImageToWorldPlaneMapGenImageToWorldPlaneMapGenImageToWorldPlaneMapgen_image_to_world_plane_map in combination with map_imagemap_imageMapImageMapImageMapImagemap_image is much more efficient than the operator image_to_world_planeimage_to_world_planeImageToWorldPlaneImageToWorldPlaneImageToWorldPlaneimage_to_world_plane because the mapping function needs to be computed only once.

注意

image_to_world_planeimage_to_world_planeImageToWorldPlaneImageToWorldPlaneImageToWorldPlaneimage_to_world_plane can be executed on OpenCL devices if the input image does not exceed the maximum size of image objects of the selected device. There can be slight differences in the output compared to the execution on the CPU.

执行信息

• 支持 OpenCL 计算设备。
• 多线程类型：可重入（与非独占算子并行运行）。
• 多线程作用域：全局（可从任何线程调用）。
• 在元组级别上自动并行化。

参数

示例（HDevelop）

* Calibrate camera.
calibrate_cameras (CalibDataID, Error)
* Obtain camera parameters.
get_calib_data (CalibDataID, 'camera', 0, 'params', CamParam)
* Example values, if no calibration data is available:
CamParam := ['area_scan_division', 0.0087, -1859, 8.65e-006, 8.6e-006, \
             362.5, 291.6, 768, 576]
* Get reference pose (pose 4 of calibration object 0).
get_calib_data (CalibDataID, 'calib_obj_pose',\
                [0,4], 'pose', Pose)
* Example values, if no calibration data is available:
Pose := [-0.11, -0.21, 2.51, 352.73, 346.73, 336.48, 0]
* Compensate thickness of plate.
set_origin_pose (Pose, -1.125, -1.0, 0, PoseNewOrigin)
* Transform the image into the world plane.
read_image (Image, 'calib/calib-3d-coord-04')
image_to_world_plane (Image, ImageWorld, CamParam, PoseNewOrigin,\
                      900, 800, 0.0025, 'bilinear')

结果

image_to_world_planeimage_to_world_planeImageToWorldPlaneImageToWorldPlaneImageToWorldPlaneimage_to_world_plane 在所有参数值正确时返回 2 (H_MSG_TRUE)。如有必要，则抛出异常。

可能的前趋

create_posecreate_poseCreatePoseCreatePoseCreatePosecreate_pose, hom_mat3d_to_posehom_mat3d_to_poseHomMat3dToPoseHomMat3dToPoseHomMat3dToPosehom_mat3d_to_pose, camera_calibrationcamera_calibrationCameraCalibrationCameraCalibrationCameraCalibrationcamera_calibration, hand_eye_calibrationhand_eye_calibrationHandEyeCalibrationHandEyeCalibrationHandEyeCalibrationhand_eye_calibration, set_origin_poseset_origin_poseSetOriginPoseSetOriginPoseSetOriginPoseset_origin_pose

替代

gen_image_to_world_plane_mapgen_image_to_world_plane_mapGenImageToWorldPlaneMapGenImageToWorldPlaneMapGenImageToWorldPlaneMapgen_image_to_world_plane_map, map_imagemap_imageMapImageMapImageMapImagemap_image

另见

contour_to_world_plane_xldcontour_to_world_plane_xldContourToWorldPlaneXldContourToWorldPlaneXldContourToWorldPlaneXldcontour_to_world_plane_xld, image_points_to_world_planeimage_points_to_world_planeImagePointsToWorldPlaneImagePointsToWorldPlaneImagePointsToWorldPlaneimage_points_to_world_plane

模块

标定

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