IJP-JavaCV intends to help in working with OpenCV and JavaCV from JVM languages, like Scala. It is focused on working with ImageJ, but can be used without it.
- Utilities for loading and displaying images using JavaCV
- Helper for converting between OpenCV and Scala/Java constructs
- API for conversion between ImageJ and OpenCV types
All of OpenCV/JavaCV can be accessed from ImageJ through scripting. You can use any ImageJ scripting language, including Scala, JavaScript, Python (Jython). Intention of IJP-JavaCV is to make that scripting less verbose, proving utilities to make interaction with OpenCV API simpler.
Sample Scala scripts can be found in Examples-ImageJ.
Here is an example of a ImageJ's Scala script that is using CCheckerDetector (ColorChecker calibration chart detector):
import ij.IJ
import ij_plugins.javacv.IJOpenCVConverters.toMat
import ij_plugins.javacv.mcc.Utils.*
import org.bytedeco.opencv.global.opencv_mcc.*
import org.bytedeco.opencv.opencv_mcc.*
// Load image
val imp = IJ.openImage("data/IMG_0903_025p-crop.png")
if (imp != null) {
imp.show()
// ColorChecker detector requires RGB image as input
val cp = toColorProcessor(imp)
// Convert RGB image to OpenCV representation
val mat = toMat(cp)
// Create chart detector
val detector = CCheckerDetector.create()
// Detect chart and display chart outline as ROI
if (detector.process(mat, MCC24)) {
val checker = detector.getBestColorChecker
imp.setRoi(toPolygonRoi(checker.getBox))
} else
IJ.showMessage("ColorChecker not detected")
} else
IJ.noImage()Many examples of using OpenCV and JavaCV can be found in OpenCV Cookbook Examples project.
The core functionality can be used as a library without ImageJ. You will need to add dependency on "net.sf.ij-plugins: ijp-javacv-core_3". For instance, for SBT:
libraryDependencies += "net.sf.ij-plugins" % "ijp-javacv-core_3" % versionSample Scala scripts can be found in [Examples-CLI]. Here is an example of a ImageJ's Scala script that is using CCheckerDetector (ColorChecker calibration chart detector):
import ij_plugins.javacv.mcc.Utils.*
import ij_plugins.javacv.util.OpenCVUtils.*
import org.bytedeco.opencv.global.opencv_imgcodecs.IMREAD_COLOR
import org.bytedeco.opencv.global.opencv_mcc.*
import org.bytedeco.opencv.opencv_core.*
import org.bytedeco.opencv.opencv_mcc.*
import java.io.File
// We force loading as color image (IMREAD_COLOR),
// as ColorChecker Detector expects only color images
val mat = loadAndShow(new File("data/IMG_0903_025p-crop.png"), IMREAD_COLOR)
// Create detector
val detector = CCheckerDetector.create()
// Detect chart and display tiles, if found
if (detector.process(mat, MCC24)) {
// Get detected chart
val checker = detector.getBestColorChecker
// Draw detected tiles
CCheckerDraw
.create(checker, scalar(255, 255, 255), 1)
.draw(mat)
show(mat, "Detected ColorChecker tiles")
} else
println("ColorChecker not detected")Some of the functionality of OpenCV/JavaCV is exposed through ImageJ plugins
- ColorChecker Detector
- Hough Circles
- Interactive segmentation using GrabCut algorithm
More information about plugins is in the Wiki
Plugin binaries are provided on the Releases page
