cv2.findTransformECC (1/2)

Raw wrapper of cv2.findTransformECC(templateImage, inputImage, warpMatrix, motionType, criteria, inputMask, gaussFiltSize). Parameters marked '?' are optional; blank means OpenCV default. See the OpenCV documentation for details.

By bmad4ever·Created 3 months ago·Updated 2 days ago· 0

templateImage
inputImage
warpMatrix
inputMask

float
nparray

◄motionTypeMOTION_AFFINE►

◄criteria_typemax count or epsilon (whichever first)►

◄criteria_max_count30►

◄criteria_epsilon0.00►

◄gaussFiltSize0►

Categoryimage/CV/low-level/cv2 F

Inputs (9)

Name	Type	Default	Description
templateImage	NPARRAY,IMAGE,MASK		1 or 3 channel template image; CV_8U, CV_16U, CV_32F, CV_64F type. Accepts a ComfyUI IMAGE/MASK directly (frame 0 of a batch) or an NPARRAY. Arithmetic ops (add, multiply, etc.) process the full IMAGE batch when both inputs have the same batch size.
inputImage	NPARRAY,IMAGE,MASK		input image which should be warped with the final warpMatrix in order to provide an image similar to templateImage, same type as templateImage. Accepts a ComfyUI IMAGE/MASK directly (frame 0 of a batch) or an NPARRAY. Arithmetic ops (add, multiply, etc.) process the full IMAGE batch when both inputs have the same batch size.
warpMatrix	NPARRAY		floating-point $2\times 3$ or $3\times 3$ mapping matrix (warp). A data array (points / matrix), NOT an image - only an NPARRAY link is accepted here.
motionType	COMBO	MOTION_AFFINE	parameter, specifying the type of motion: - MOTION_TRANSLATION sets a translational motion model; warpMatrix is $2\times 3$ with the first $2\times 2$ part being the unity matrix and the rest two parameters being estimated. - MOTION_EUCLIDEAN sets a Euclidean (rigid) transformation as motion model; three parameters are estimated; warpMatrix is $2\times 3$. - MOTION_AFFINE sets an affine motion model (DEFAULT); six parameters are estimated; warpMatrix is $2\times 3$. - MOTION_HOMOGRAPHY sets a homography as a motion model; eight parameters are estimated;\`warpMatrix\` is $3\times 3$.
criteria_type	COMBO	max count or epsilon (whichever first)	When to stop iterating: after max_count iterations, when the change drops below epsilon, or whichever comes first.
criteria_max_count	INT	301–2147483647	Maximum iterations (ignored when 'epsilon only').
criteria_epsilon	FLOAT	0.000–1e+38	Target accuracy / smallest change worth continuing for (ignored when 'max count only').
inputMask	NPARRAY,IMAGE,MASK		An optional single channel mask to indicate valid values of inputImage. Accepts a ComfyUI IMAGE/MASK directly (frame 0 of a batch) or an NPARRAY. Arithmetic ops (add, multiply, etc.) process the full IMAGE batch when both inputs have the same batch size.
gaussFiltSize	INT	0-2147483648–2147483647	An optional value indicating size of gaussian blur filter; (DEFAULT: 5) The function estimates the optimum transformation (warpMatrix) with respect to ECC criterion (), that is $$\texttt{warpMatrix} = \arg\max_{W} \texttt{ECC}(\texttt{templateImage}(x,y),\texttt{inputImage}(x',y'))$$ where $$\begin{bmatrix} x' \ y' \end{bmatrix} = W \cdot \begin{bmatrix} x \ y \ 1 \end{bmatrix}$$ (the equation holds with homogeneous coordinates for homography). It returns the final enhanced correlation coefficient, that is the correlation coefficient between the template image and the final warped input image. When a $3\times 3$ matrix is given with motionType =0, 1 or 2, the third row is ignored. Unlike findHomography and estimateRigidTransform, the function findTransformECC implements an area-based alignment that builds on intensity similarities. In essence, the function updates the initial transformation that roughly aligns the images. If this information is missing, the identity warp (unity matrix) is used as an initialization. Note that if images undergo strong displacements/rotations, an initial transformation that roughly aligns the images is necessary (e.g., a simple euclidean/similarity transform that allows for the images showing the same image content approximately). Use inverse warping in the second image to take an image close to the first one, i.e. use the flag WARP_INVERSE_MAP with warpAffine or warpPerspective. See also the OpenCV sample image_alignment.cpp that demonstrates the use of the function. Note that the function throws an exception if algorithm does not converges.

Outputs (2)

Name	Type	Description
float	FLOAT	—
nparray	NPARRAY	—