Point Cloud to Depth Map

Operator Function

Convert the input 3D point cloud image into a 2D depth map. Map the z-value of each point to the grayscale value in the 2D depth map.

Parameter Introduction

Input Parameters

Parameter	Range	Default Value	Description	Illustration
Input Image	0-8	0	The IM number for image input

Calculation Parameters

Parameter	Range	Default Value	Description	Illustration
Output Depth Map Type	Grayscale Image/Floating Point Image	Grayscale Image	Grayscale Image: Each pixel value corresponds to the normalized grayscale value of height Floating Point Image: Each pixel value corresponds to the actual height value
Auto Detect Window	true/false	true	If selected, automatically calculate the point cloud range to be converted, which is the bounding box range of the point cloud image; if deselected, the Region option appears for manually setting the conversion area.
Region			Only effective when Auto Detect Window is deselected, requires manual setting of the conversion region.
Interpolation	None	None	Interpolation methods not currently provided
Precision	8-bit/16-bit	8-bit	Choose 8-bit or 16-bit. 8-bit grayscale range is [0, 255], 16-bit grayscale range is [0, 65535].
Auto Detect Z-value Range	true/false	true	If selected, automatically correspond the maximum height value in the current conversion region to black pixels, and the minimum height value to white pixels.
Height Value Corresponding to Black Pixel		0.000	Required when Auto Detect Z-value Range is deselected.
Height Value Corresponding to White Pixel		0.000	Required when Auto Detect Z-value Range is deselected.
Auto Detection	true/false	true	When enabled, the input point cloud must be an ordered point cloud, and the X Resolution and Y Resolution of the point cloud will be calculated based on the row and column count of the ordered point cloud.
X Resolution		0.100	Set the width of a single pixel in the converted depth map. The point spacing should be set as close as possible to the precision of the depth map camera's z-axis direction. Too small will cause many stripes in the image, too large will blur the image. Note: Requires manual setting when Auto Detection is turned off.
Y Resolution		0.100	Set the height of a single pixel in the converted depth map. The resolution should be set as close as possible to the point spacing set when the point cloud image was captured by the camera. Too small will cause many stripes in the image, too large will blur the image. Note: Requires manual setting when Auto Detection is turned off.
Output Image	0-8	0	The IM number for image output

Note: In manual mode, setting the resolution too small will cause black stripes in the output depth image, as shown below. Solution: adjust the resolution to be slightly larger than the actual point spacing.

Result Display

Parameter	Range	Default Value	Description	Illustration
ROI Point Set			Only effective when Auto Detect Window is deselected, displays the point set in the ROI-selected area if enabled

Output Parameters

Name	Type	Range	Description
Result	bool	true/false	true for success false for failure
Warning	bool	true/false	true indicates a warning false indicates none
Message	string		Output success, error, or warning messages. Empty if no error or warning
Time	float		Operator execution time, unit: ms
offset_x	float		X-axis offset
offset_y	float		Y-axis offset
resolution_x	float		X-axis resolution
resolution_y	float		Y-axis resolution

Mapping Relationship Between Height Value and Depth Value

Height Value	Depth Value
Invalid point (nan)	0
Height Value Corresponding to Black Pixel	2
Height Value Corresponding to White Pixel	$2^n-2$ n is bit depth
Greater than Height Value Corresponding to Black Pixel	1
Less than Height Value Corresponding to White Pixel	$2^n-1$ n is bit depth

Exception Troubleshooting

No.	Exception Information	Corresponding Parameter	Solution
1	Input point cloud is empty		Check if input point cloud is empty
2	Auto detection resolution mode requires ordered point cloud input		Auto detection resolution mode requires ordered point cloud input
3	Input value {0} is invalid output depth map type	Output Depth Map Type	Only supports grayscale image, floating image
4	Point cloud to depth map conversion failed		Check if both xy resolutions are greater than 0

Example Introduction

Engineering Design

1. Select the Load Point Cloud tool to load the required 3D point cloud image into IM0.

2. Select the Point Cloud to Depth Map tool.

Tool Usage

1. Select the input image for operation. The image number must match the IM number where the image is located in the project.

2. Select Auto Detect Window.

3. Set the parameters.

4. Check the desired display content in the Result Display section.

5. Click Test to check if the image window and parameters meet expectations.

6. If everything is correct, click Save, then run the operator in the run list. You can view the results in the corresponding IM.