Node.jsでFaceTime HDカメラを使う

こんばんは、トイレトレーニングが順調に進んでいる長男ですが、おしっこをギリギリまで溜めてしまうようで、毎度トイレで大人並みの量をしているので、何とか、途中でトイレに行けせたく、声かけても「でない！行きたくない」と拒否され、毎度ギリギリでトイレに駆け込むことが多々あります。@kjunichiです。

マルチプラットフォームで簡単にWebCamを使うには

OpenCVをつかうと、RustやGoでもわずか数行で、ウィンドウを開いて、WebCamのキャプチャー結果を表示することが出来る。

Node.jsから直接OpenCVを使う

OpenCVの複雑な画像処理をするわけでもないので、node-ffiを使って、直接libopencv_highguiを叩く

必要なモジュール

npm install ffi ref ref-array ref-struct

コード

File: webcam.js ------------------------- var ref = require('ref'); var ffi = require('ffi'); var ArrayType = require('ref-array'); var Struct = require('ref-struct'); var char = ref.types.char; var charPtr = ref.refType('char'); var IplROIVal = Struct({ 'coi': 'int', /* 0 - no COI (all channels are selected), 1 - 0th channel is selected ...*/ 'xOffset': 'int', 'yOffset': 'int', 'width': 'int', 'height': 'int' }); var IplROIPtr = ref.refType(IplROIVal); /* var IplTitleInfoVal = Struct({ }); val IplTitleInfoPtr = ref.refType(IplTitleInfoVal); */ var IplImageVal = Struct({ 'nSize': 'int', /* sizeof(IplImage) */ 'ID': 'int', /* version (=0)*/ 'nChannels': 'int', /* Most of OpenCV functions support 1,2,3 or 4 channels */ 'alphaChannel': 'int', /* Ignored by OpenCV */ 'depth': 'int', /* Pixel depth in bits: IPL_DEPTH_8U, IPL_DEPTH_8S, IPL_DEPTH_16S, IPL_DEPTH_32S, IPL_DEPTH_32F and IPL_DEPTH_64F are supported. */ 'colorModel': ArrayType('char', 4), /* Ignored by OpenCV */ 'channelSeq': ArrayType('char', 4), /* ditto */ 'dataOrder': 'int', /* 0 - interleaved color channels, 1 - separate color channels. cvCreateImage can only create interleaved images */ 'origin': 'int', /* 0 - top-left origin, 1 - bottom-left origin (Windows bitmaps style). */ 'align': 'int', /* Alignment of image rows (4 or 8). OpenCV ignores it and uses widthStep instead. */ 'width': 'int', /* Image width in pixels. */ 'height': 'int', /* Image height in pixels. */ 'roi': IplROIPtr, /* Image ROI. If NULL, the whole image is selected. */ 'maskROI': 'pointer', //ref.refType(IplImageVal), /* Must be NULL. */ 'imageId': 'pointer', /* " " */ 'tileInfo': 'pointer', //ref.refType(IplTitleInfoPtr), /* " " */ 'imageSize': 'int', /* Image data size in bytes (==image->height*image->widthStep in case of interleaved data)*/ 'imageData': charPtr, /* Pointer to aligned image data. */ 'widthStep': 'int', /* Size of aligned image row in bytes. */ 'BorderMode': ArrayType('int', 4), //[4]; /* Ignored by OpenCV. */ 'BorderConst': ArrayType('int', 4), //[4]; /* Ditto. */ 'imageDataOrigin': charPtr /* Pointer to very origin of image data (not necessarily aligned) - needed for correct deallocation */ }) var CaptureVal = Struct({ }); var CaptureValPtr = ref.refType(CaptureVal); //console.log(IplImageVal); var IplImagePtr = ref.refType(IplImageVal); var Capture = ref.types.void; var CapturePtr = ref.refType(Capture); var intPtr = ref.refType('int'); var libopencv_highgui = ffi.Library('libopencv_highgui', { 'cvDestroyAllWindows': ['void', []], 'cvNamedWindow': ['int', ['string', 'int']], 'cvShowImage': ['void', ['string', IplImagePtr]], 'cvWaitKey': ['int', ['int']], 'cvCreateCameraCapture': [CaptureValPtr, ['int']], 'cvQueryFrame': [IplImagePtr, [CaptureValPtr]], 'cvSaveImage': ['int', ['string', IplImagePtr, intPtr]] }); libopencv_highgui.cvNamedWindow("WebCam Capture", 1); var cap = libopencv_highgui.cvCreateCameraCapture(0); var loop = function() { var frame = libopencv_highgui.cvQueryFrame(cap); libopencv_highgui.cvShowImage("nao", frame); var c = libopencv_highgui.cvWaitKey(2); if (c == 0x1b) { libopencv_highgui.cvDestroyAllWindows(); return; } if(c == 0x20) { libopencv_highgui.cvSaveImage("snap.jpg",frame,ref.NULL); return; } setImmediate(loop); }; loop();