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  • ImageAlign
  • How to place it
  • Inputs and Outputs
  • How it works
  • Usage
  • Examples of functionality
  • Reference

ImageAlign

ImageAlign node is used for aligning sensor frames, like depth map (from ToF/Stereo) to color frame (RGB-D), or to align temperature/thermal frame to color frame (RGB-Thermal) when specifying depth plane.

How to place it

Python
C++

Python

Python
1with dai.Pipeline() as pipeline:
2    img_align = pipeline.create(dai.node.ImageAlign)

Inputs and Outputs

React Flow

How it works

ImageAlign aligns input frame and aligns it to inputAlignTo frame. The inputAlignTo is only read once to extract the frame metadata, then the input frame is reprojected and aligned to it based on the extrinsic calibration between the two sensors.

Usage

Python
C++

Python

Python
1with dai.Pipeline() as pipeline:
2    rgb_cam = pipeline.create(dai.node.Camera).build(dai.CameraBoardSocket.CAM_A)
3    video_stream = rgb_cam.requestOutput(size=(1280, 960))
4
5    # Create left/right stereo cameras & StereoDepth node
6    left = pipeline.create(dai.node.Camera).build(dai.CameraBoardSocket.CAM_B)
7    right = pipeline.create(dai.node.Camera).build(dai.CameraBoardSocket.CAM_C)
8    stereo = pipeline.create(dai.node.StereoDepth)
9
10    left.requestOutput(size=(640, 400)).link(stereo.left)
11    right.requestOutput(size=(640, 400)).link(stereo.right)
12
13    # Now create ImageAlign node and align stereo depth to RGB stream
14    img_align = pipeline.create(dai.node.ImageAlign)
15    stereo.depth.link(align.input)
16    video_stream.link(align.inputAlignTo)
17
18    # If you want to have synchronized aligned depth and color stream, you'd want to use Sync node
19    sync = pipeline.create(dai.node.Sync)
20    img_align.outputAligned.link(sync.inputs['aligned_depth'])
21    video_stream.link(sync.inputs["color"])
22
23    # Create an output queue, so you can get sycned frames to the host computer
24    queue = sync.out.createOutputQueue()
25
26    # ...

Examples of functionality

Reference

class

dai::node::ImageAlign

#include ImageAlign.hpp
variable
std::shared_ptr< ImageAlignConfig > initialConfig
Initial config to use when calculating spatial location data.
variable
Input inputConfig
Input message with ability to modify parameters in runtime. Default queue is non-blocking with size 4.
variable
Input input
Input message. Default queue is non-blocking with size 4.
variable
Input inputAlignTo
Input align to message. Default queue is non-blocking with size 1.
variable
Output outputAligned
Outputs ImgFrame message that is aligned to inputAlignTo.
variable
Output passthroughInput
Passthrough message on which the calculation was performed. Suitable for when input queue is set to non-blocking behavior.
function
ImageAlign & setOutputSize(int alignWidth, int alignHeight)
Specify the output size of the aligned image
function
ImageAlign & setOutKeepAspectRatio(bool keep)
Specify whether to keep aspect ratio when resizing
function
ImageAlign & setInterpolation(Interpolation interp)
Specify interpolation method to use when resizing
function
ImageAlign & setNumShaves(int numShaves)
Specify number of shaves to use for this node
function
ImageAlign & setNumFramesPool(int numFramesPool)
Specify number of frames in the pool
inline function
DeviceNodeCRTP()
inline function
DeviceNodeCRTP(const std::shared_ptr< Device > & device)
inline function
DeviceNodeCRTP(std::unique_ptr< Properties > props)
inline function
DeviceNodeCRTP(std::unique_ptr< Properties > props, bool confMode)
inline function
DeviceNodeCRTP(const std::shared_ptr< Device > & device, std::unique_ptr< Properties > props, bool confMode)

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