zOpenCV API Reference

Complete Zig bindings for OpenCV 4.13.0 with opencv_contrib modules.

Version: 0.1.0 | Zig: 0.16.0-dev.2510+bcb5218a2 | OpenCV: 4.13.0 | Functions: 651 | Tests: 560

Module Summary

Core Modules (15)

Module	Zig File	Functions	OpenCV Module	Status
core	`core.zig`	171	`opencv2/core.hpp`	✅ Complete
imgproc	`imgproc.zig`	115	`opencv2/imgproc.hpp`	✅ Complete
calib3d	`calib3d.zig`	37	`opencv2/calib3d.hpp`	✅ Complete
features2d	`features2d.zig`	41	`opencv2/features2d.hpp`	✅ Complete
photo	`photo.zig`	39	`opencv2/photo.hpp`	✅ Complete
videoio	`videoio.zig`	29	`opencv2/videoio.hpp`	✅ Complete
video	`video.zig`	27	`opencv2/video.hpp`	✅ Complete
dnn	`dnn.zig`	21	`opencv2/dnn.hpp`	✅ Complete
highgui	`highgui.zig`	19	`opencv2/highgui.hpp`	✅ Complete
objdetect	`objdetect.zig`	19	`opencv2/objdetect.hpp`	✅ Complete
ml	`ml.zig`	17	`opencv2/ml.hpp`	✅ Complete
stitching	`stitching.zig`	13	`opencv2/stitching.hpp`	✅ Complete
imgcodecs	`imgcodecs.zig`	9	`opencv2/imgcodecs.hpp`	✅ Complete
flann	`flann.zig`	5	`opencv2/flann.hpp`	✅ Complete

Contrib Modules (13)

Module	Zig File	Functions	OpenCV Module	Status
xphoto	`contrib/xphoto.zig`	10	`opencv2/xphoto.hpp`	✅ Complete
ximgproc	`contrib/ximgproc.zig`	9	`opencv2/ximgproc.hpp`	✅ Complete
img_hash	`contrib/img_hash.zig`	9	`opencv2/img_hash.hpp`	✅ Complete
face	`contrib/face.zig`	8	`opencv2/face.hpp`	✅ Complete
bgsegm	`contrib/bgsegm.zig`	8	`opencv2/bgsegm.hpp`	✅ Complete
text	`contrib/text.zig`	7	`opencv2/text.hpp`	✅ Complete
dnn_superres	`contrib/dnn_superres.zig`	7	`opencv2/dnn_superres.hpp`	✅ Complete
xfeatures2d	`contrib/xfeatures2d.zig`	6	`opencv2/xfeatures2d.hpp`	✅ Complete
tracking	`contrib/tracking.zig`	6	`opencv2/tracking.hpp`	✅ Complete
bioinspired	`contrib/bioinspired.zig`	6	`opencv2/bioinspired.hpp`	✅ Complete
aruco	`contrib/aruco.zig`	6	`opencv2/aruco.hpp`	✅ Complete
saliency	`contrib/saliency.zig`	4	`opencv2/saliency.hpp`	✅ Complete
optflow	`contrib/optflow.zig`	3	`opencv2/optflow.hpp`	✅ Complete

API Cross-Reference: Zig ↔ OpenCV C++

Core Types

Zig Type	OpenCV C++ Type	Description
`cv.Mat`	`cv::Mat`	N-dimensional dense array (image container)
`cv.Mats`	`std::vector<cv::Mat>`	Vector of Mat objects
`cv.Point`	`cv::Point`	2D integer point
`cv.Point2f`	`cv::Point2f`	2D float point
`cv.Point3f`	`cv::Point3f`	3D float point
`cv.Rect`	`cv::Rect`	Rectangle (x, y, width, height)
`cv.Size`	`cv::Size`	2D size (width, height)
`cv.Scalar`	`cv::Scalar`	4-element vector (for colors, etc.)
`cv.PointVector`	`std::vector<cv::Point>`	Vector of points
`cv.Point2fVector`	`std::vector<cv::Point2f>`	Vector of 2D float points
`cv.PointsVector`	`std::vector<std::vector<cv::Point>>`	Vector of point vectors (contours)
`cv.RectVector`	`std::vector<cv::Rect>`	Vector of rectangles
`cv.RotatedRect`	`cv::RotatedRect`	Rotated rectangle
`cv.TermCriteria`	`cv::TermCriteria`	Iteration termination criteria
`cv.RNG`	`cv::RNG`	Random number generator

Core Module — Mat Operations

Zig Function	OpenCV C++	Description
`Mat.init()`	`cv::Mat()`	Create empty Mat
`Mat.initWithSize(r, c, t)`	`cv::Mat(r, c, t)`	Create sized Mat
`Mat.zeros(r, c, t)`	`cv::Mat::zeros(r, c, t)`	Create zero-filled Mat
`Mat.ones(r, c, t)`	`cv::Mat::ones(r, c, t)`	Create ones-filled Mat
`Mat.eye(r, c, t)`	`cv::Mat::eye(r, c, t)`	Create identity Mat
`mat.clone()`	`mat.clone()`	Deep copy
`mat.copyTo(dst)`	`mat.copyTo(dst)`	Copy to destination
`mat.convertTo(dst, t, a, b)`	`mat.convertTo(dst, t, a, b)`	Convert type
`mat.reshape(cn, rows)`	`mat.reshape(cn, rows)`	Reshape without copy
`mat.t()`	`mat.t()`	Transpose
`mat.inv(method)`	`mat.inv(method)`	Matrix inverse
`mat.mul(other, scale)`	`mat.mul(other, scale)`	Element-wise multiply
`mat.dot(other)`	`mat.dot(other)`	Dot product
`mat.cross(other)`	`mat.cross(other)`	Cross product
`mat.submat(roi)`	`mat(roi)`	ROI submatrix
`mat.rowAt(y)`	`mat.row(y)`	Single row
`mat.colAt(x)`	`mat.col(x)`	Single column
`mat.setTo(value)`	`mat.setTo(value)`	Set all elements
`mat.getDouble(r, c)`	`mat.at<double>(r, c)`	Get element
`mat.setDouble(r, c, v)`	`mat.at<double>(r, c) = v`	Set element

Image Processing (imgproc)

Zig Function	OpenCV C++	Description
`cvtColor(src, dst, code)`	`cv::cvtColor()`	Color space conversion
`resize(src, dst, ...)`	`cv::resize()`	Resize image
`gaussianBlur(src, dst, ...)`	`cv::GaussianBlur()`	Gaussian smoothing
`medianBlur(src, dst, k)`	`cv::medianBlur()`	Median smoothing
`blur(src, dst, ksize)`	`cv::blur()`	Box filter
`bilateralFilter(...)`	`cv::bilateralFilter()`	Edge-preserving smoothing
`canny(src, dst, ...)`	`cv::Canny()`	Edge detection
`sobel(src, dst, ...)`	`cv::Sobel()`	Gradient (Sobel)
`laplacian(src, dst, ...)`	`cv::Laplacian()`	Gradient (Laplacian)
`erode(src, dst, ...)`	`cv::erode()`	Morphological erosion
`dilate(src, dst, ...)`	`cv::dilate()`	Morphological dilation
`morphologyEx(src, dst, ...)`	`cv::morphologyEx()`	Advanced morphology
`threshold(src, dst, ...)`	`cv::threshold()`	Thresholding
`adaptiveThreshold(...)`	`cv::adaptiveThreshold()`	Adaptive thresholding
`findContours(img, m, mth)`	`cv::findContours()`	Contour detection
`drawContours(img, ...)`	`cv::drawContours()`	Contour drawing
`boundingRect(contour)`	`cv::boundingRect()`	Bounding rectangle
`minAreaRect(pts)`	`cv::minAreaRect()`	Minimum area rectangle
`contourArea(c, oriented)`	`cv::contourArea()`	Contour area
`arcLength(c, closed)`	`cv::arcLength()`	Contour perimeter
`approxPolyDP(c, eps, cl)`	`cv::approxPolyDP()`	Polygon approximation
`convexHull(pts, cw)`	`cv::convexHull()`	Convex hull
`equalizeHist(src, dst)`	`cv::equalizeHist()`	Histogram equalization
`matchTemplate(i, t, r, m)`	`cv::matchTemplate()`	Template matching
`line(img, pt1, pt2, ...)`	`cv::line()`	Draw line
`rectangle(img, rect, ...)`	`cv::rectangle()`	Draw rectangle
`circle(img, c, r, ...)`	`cv::circle()`	Draw circle
`ellipse(img, ...)`	`cv::ellipse()`	Draw ellipse
`putText(img, text, ...)`	`cv::putText()`	Draw text
`warpAffine(...)`	`cv::warpAffine()`	Affine transform
`warpPerspective(...)`	`cv::warpPerspective()`	Perspective transform
`houghLines(...)`	`cv::HoughLines()`	Line detection
`houghCircles(...)`	`cv::HoughCirclesf()`	Circle detection
`moments(src, binary)`	`cv::moments()`	Image moments
`filter2D(...)`	`cv::filter2D()`	Custom convolution
`goodFeaturesToTrack(...)`	`cv::goodFeaturesToTrack()`	Corner detection
`pyrDown(src, dst, ...)`	`cv::pyrDown()`	Downsample
`pyrUp(src, dst, ...)`	`cv::pyrUp()`	Upsample

Image Codecs (imgcodecs)

Zig Function	OpenCV C++	Description
`imread(file, flags)`	`cv::imread()`	Read image from file
`imwrite(file, img)`	`cv::imwrite()`	Write image to file
`imwriteWithParams(...)`	`cv::imwrite()`	Write with compression params
`imencode(ext, img, params)`	`cv::imencode()`	Encode to memory buffer
`imdecode(buf, flags)`	`cv::imdecode()`	Decode from memory buffer
`imreadMulti(file, flags)`	`cv::imreadmulti()`	Read multi-page image
`haveImageReader(file)`	`cv::haveImageReader()`	Check reader support
`haveImageWriter(file)`	`cv::haveImageWriter()`	Check writer support
`imcount(file, flags)`	`cv::imcount()`	Count pages in file

DNN

Zig Function	OpenCV C++	Description
`Net.readNetFromDarknet(...)`	`cv::dnn::readNetFromDarknet()`	Load Darknet model
`Net.readNetFromCaffe(...)`	`cv::dnn::readNetFromCaffe()`	Load Caffe model
`Net.readNetFromTensorflow(...)`	`cv::dnn::readNetFromTensorflow()`	Load TF model
`Net.readNetFromONNX(...)`	`cv::dnn::readNetFromONNX()`	Load ONNX model
`Net.readNetFromTorch(...)`	`cv::dnn::readNetFromTorch()`	Load Torch model
`Net.readNetFromTFLite(...)`	`cv::dnn::readNetFromTFLite()`	Load TFLite model
`net.forward(name)`	`net.forward()`	Run forward pass
`net.setInput(blob, name)`	`net.setInput()`	Set network input
`net.setPreferableBackend(b)`	`net.setPreferableBackend()`	Set compute backend
`net.setPreferableTarget(t)`	`net.setPreferableTarget()`	Set compute target
`net.dump()`	`net.dump()`	Dump network structure
`blobFromImage(...)`	`cv::dnn::blobFromImage()`	Create 4D blob from image
`nmsBoxes(...)`	`cv::dnn::NMSBoxes()`	Non-maximum suppression

Video Analysis (video)

Zig Function	OpenCV C++	Description
`BackgroundSubtractorMOG2.init()`	`cv::createBackgroundSubtractorMOG2()`	MOG2 background subtractor
`BackgroundSubtractorKNN.init()`	`cv::createBackgroundSubtractorKNN()`	KNN background subtractor
`calcOpticalFlowPyrLK(...)`	`cv::calcOpticalFlowPyrLK()`	Sparse optical flow
`calcOpticalFlowFarneback(...)`	`cv::calcOpticalFlowFarneback()`	Dense optical flow
`Tracker.initMIL()`	`cv::TrackerMIL::create()`	MIL tracker

Video I/O (videoio)

Zig Function	OpenCV C++	Description
`VideoCapture.init()`	`cv::VideoCapture()`	Create capture
`VideoCapture.initFromFile(f)`	`cv::VideoCapture(f)`	Open file
`VideoCapture.initFromIndex(i)`	`cv::VideoCapture(i)`	Open camera
`vc.read(frame)`	`vc.read(frame)`	Read next frame
`vc.get(prop)`	`vc.get(prop)`	Get property
`vc.set(prop, val)`	`vc.set(prop, val)`	Set property
`VideoWriter.initWithParams(...)`	`cv::VideoWriter(...)`	Create writer
`vw.write(img)`	`vw.write(img)`	Write frame
`fourcc(c1,c2,c3,c4)`	`cv::VideoWriter::fourcc()`	Create FourCC code

Features2D

Zig Function	OpenCV C++	Description
`ORB.init()`	`cv::ORB::create()`	ORB detector
`SIFT.init()`	`cv::SIFT::create()`	SIFT detector
`AKAZE.init()`	`cv::AKAZE::create()`	AKAZE detector
`detector.detect(img, kps)`	`detector->detect()`	Detect keypoints
`detector.compute(img, kps, desc)`	`detector->compute()`	Compute descriptors
`detector.detectAndCompute(...)`	`detector->detectAndCompute()`	Detect + compute
`BFMatcher.init()`	`cv::BFMatcher()`	Brute-force matcher
`matcher.knnMatch(q, t, k)`	`matcher.knnMatch()`	KNN matching

Object Detection (objdetect)

Zig Function	OpenCV C++	Description
`CascadeClassifier.init()`	`cv::CascadeClassifier()`	Create classifier
`cc.load(file)`	`cc.load(file)`	Load cascade file
`cc.detectMultiScale(...)`	`cc.detectMultiScale()`	Multi-scale detection
`HOGDescriptor.init()`	`cv::HOGDescriptor()`	HOG detector
`hog.setSVMDetector(type)`	`hog.setSVMDetector()`	Set people detector
`hog.detectMultiScale(...)`	`hog.detectMultiScale()`	Detect objects
`QRCodeDetector.init()`	`cv::QRCodeDetector()`	QR code detector
`qr.detectAndDecode(...)`	`qr.detectAndDecode()`	Detect and decode QR

Photo

Zig Function	OpenCV C++	Description
`fastNlMeansDenoising(...)`	`cv::fastNlMeansDenoising()`	Grayscale denoising
`fastNlMeansDenoisingColored(...)`	`cv::fastNlMeansDenoisingColored()`	Color denoising
`inpaint(src, mask, dst, ...)`	`cv::inpaint()`	Image inpainting
`detailEnhance(src, dst, ...)`	`cv::detailEnhance()`	Detail enhancement
`pencilSketch(src, ...)`	`cv::pencilSketch()`	Pencil sketch effect
`stylization(src, dst, ...)`	`cv::stylization()`	Stylization
`seamlessClone(src, dst, ...)`	`cv::seamlessClone()`	Seamless cloning
`decolorization(src, ...)`	`cv::decolor()`	Decolorization
`MergeMertens.init()`	`cv::createMergeMertens()`	HDR merge (Mertens)
`Tonemap.init(gamma)`	`cv::createTonemap()`	Tone mapping
`AlignMTB.init(...)`	`cv::createAlignMTB()`	Exposure alignment

Calibration & 3D (calib3d)

Zig Function	OpenCV C++	Description
`calibrateCamera(...)`	`cv::calibrateCamera()`	Camera calibration
`undistort(src, dst, ...)`	`cv::undistort()`	Lens undistortion
`findChessboardCorners(...)`	`cv::findChessboardCorners()`	Chessboard detection
`solvePnP(...)`	`cv::solvePnP()`	PnP pose estimation
`findHomography(...)`	`cv::findHomography()`	Homography estimation
`findFundamentalMat(...)`	`cv::findFundamentalMat()`	Fundamental matrix
`findEssentialMat(...)`	`cv::findEssentialMat()`	Essential matrix
`stereoCalibrate(...)`	`cv::stereoCalibrate()`	Stereo calibration
`drawFrameAxes(...)`	`cv::drawFrameAxes()`	Draw 3D coordinate axes

Machine Learning (ml)

Zig Function	OpenCV C++	Description
`SVM.init()`	`cv::ml::SVM::create()`	Create SVM
`svm.train(samples, layout, responses)`	`svm->train()`	Train model
`svm.predict(samples, results, flags)`	`svm->predict()`	Predict
`svm.setType(type)` / `setKernel(k)`	`svm->setType()`	Configure SVM
`KNearest.init()`	`cv::ml::KNearest::create()`	Create KNN
`knn.train(samples, layout, responses)`	`knn->train()`	Train model
`knn.predict(samples, ...)`	`knn->predict()`	Predict
`knn.setDefaultK(k)`	`knn->setDefaultK()`	Set K value

Contrib Modules Cross-Reference

Zig API	OpenCV C++	Description
`contrib.aruco.ArucoDetector`	`cv::aruco::ArucoDetector`	ArUco marker detection
`contrib.tracking.TrackerKCF`	`cv::TrackerKCF`	KCF object tracking
`contrib.face.LBPHFaceRecognizer`	`cv::face::LBPHFaceRecognizer`	Face recognition
`contrib.text.OCRTesseract`	`cv::text::OCRTesseract`	OCR via Tesseract
`contrib.xfeatures2d.SURF`	`cv::xfeatures2d::SURF`	SURF features
`contrib.ximgproc.thinning(...)`	`cv::ximgproc::thinning()`	Skeletonization
`contrib.ximgproc.niBlackThreshold(...)`	`cv::ximgproc::niBlackThreshold()`	Niblack threshold
`contrib.xphoto.WhiteBalancer`	`cv::xphoto::WhiteBalancer`	White balance
`contrib.xphoto.oilPainting(...)`	`cv::xphoto::oilPainting()`	Oil painting effect
`contrib.img_hash.PHash`	`cv::img_hash::PHash`	Perceptual hash
`contrib.img_hash.AverageHash`	`cv::img_hash::AverageHash`	Average hash
`contrib.bgsegm.BackgroundSubtractorCNT`	`cv::bgsegm::*BackgroundSubtractorCNT`	CNT bg subtraction
`contrib.bgsegm.BackgroundSubtractorGMG`	`cv::bgsegm::*BackgroundSubtractorGMG`	GMG bg subtraction
`contrib.dnn_superres.DnnSuperResImpl`	`cv::dnn_superres::DnnSuperResImpl`	DNN super resolution
`contrib.bioinspired.Retina`	`cv::bioinspired::Retina`	Bio-inspired retina
`contrib.optflow.DualTVL1OpticalFlow`	`cv::optflow::DualTVL1OpticalFlow`	TV-L1 optical flow
`contrib.saliency.StaticSaliency`	`cv::saliency::StaticSaliency*`	Saliency detection

Error Handling

All fallible functions return Zig error unions:

pub const Error = error{
    NullPointer,        // C API returned NULL (e.g., failed file load)
    MatCreationFailed,  // Mat allocation failed
    MatIsEmpty,         // Operation on empty Mat
    InvalidMatType,     // Wrong Mat type for operation
    InvalidIndex,       // Index out of bounds
    ImWriteFailed,      // Image write failed
};

Memory Management

zOpenCV uses RAII-style resource management with defer:

var mat = try cv.Mat.init();
defer mat.deinit();  // Freed at scope exit

var detector = try cv.features2d.ORB.init();
defer detector.deinit();

Building

zig build                           # Build library
zig build test                      # Run core tests
zig build test -Dcontrib=true       # Run all tests (including contrib)
zig build examples                  # Build core examples
zig build examples -Dcontrib=true   # Build all examples
zig build example-<name>            # Build specific example

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zOpenCV API Reference

Module Summary

Core Modules (15)

Contrib Modules (13)

API Cross-Reference: Zig ↔ OpenCV C++

Core Types

Core Module — Mat Operations

Image Processing (imgproc)

Image Codecs (imgcodecs)

DNN

Video Analysis (video)

Video I/O (videoio)

Features2D

Object Detection (objdetect)

Photo

Calibration & 3D (calib3d)

Machine Learning (ml)

Contrib Modules Cross-Reference

Error Handling

Memory Management

Building

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zOpenCV API Reference

Module Summary

Core Modules (15)

Contrib Modules (13)

API Cross-Reference: Zig ↔ OpenCV C++

Core Types

Core Module — Mat Operations

Image Processing (imgproc)

Image Codecs (imgcodecs)

DNN

Video Analysis (video)

Video I/O (videoio)

Features2D

Object Detection (objdetect)

Photo

Calibration & 3D (calib3d)

Machine Learning (ml)

Contrib Modules Cross-Reference

Error Handling

Memory Management

Building