ppu-ocv/image-analysis.js

A type-safe, modular, chainable image processing library built on top of OpenCV.js with a fluent API leveraging pipeline processing.

import{ImageProcessor,cv}from"./index";export function calculateMeanNormalizedLabLightness(options){const{canvas,dimension}=options;let processor=null;let resized=null;let labImg=null;let channels=null;let L=null;let mask=null;let scalarMat=null;try{processor=new ImageProcessor(canvas);resized=processor.execute("resize",{width:dimension.width,height:dimension.height}).toMat();labImg=new cv.Mat;cv.cvtColor(resized,labImg,cv.COLOR_BGR2Lab);channels=new cv.MatVector;cv.split(labImg,channels);L=channels.get(0);mask=new cv.Mat;let maxLocResult=cv.minMaxLoc(L,mask);let maxPixelValue=maxLocResult.maxVal;if(maxPixelValue===0){return 0}scalarMat=new cv.Mat(L.rows,L.cols,L.type(),new cv.Scalar(maxPixelValue));cv.divide(L,scalarMat,L,1,-1);let meanL=cv.mean(L)[0];return meanL??0}finally{processor?.destroy();labImg?.delete();channels?.delete();L?.delete();mask?.delete();scalarMat?.delete()}}export function calculateMeanGrayscaleValue(canvas){let processor=null;let grayscaleImg=null;try{processor=new ImageProcessor(canvas);grayscaleImg=processor.blur().grayscale().toMat();let mean=cv.mean(grayscaleImg)[0];return mean??0}finally{processor?.destroy()}}