這次帶給大家vue2.0呼叫攝影機步驟詳解,使用vue2.0呼叫攝影機的注意事項有哪些,下面就是實戰案例,一起來看一下。
可以在github 上下載demo連結
vue元件程式碼
<template> <p> <p style="padding:20px;"> <p class="show"> <p class="picture" :style="'backgroundImage:url('+headerImage+')'"></p> </p> <p style="margin-top:20px;"> <input type="file" id="upload" accept="image/jpg" @change="upload"> <label for="upload"></label> </p> </p> </p> </template> <script> import {Exif} from './exif.js' export default { data () { return { headerImage:'',picValue:'' } }, mounted () { }, methods: { upload (e) { let files = e.target.files || e.dataTransfer.files; if (!files.length) return; this.picValue = files[0]; this.imgPreview(this.picValue); console.log(this.picValue) }, imgPreview (file) { let self = this; let Orientation; //去获取拍照时的信息,解决拍出来的照片旋转问题 Exif.getData(file, function(){ Orientation = Exif.getTag(this, 'Orientation'); }); // 看支持不支持FileReader if (!file || !window.FileReader) return; if (/^image/.test(file.type)) { // 创建一个reader let reader = new FileReader(); // 将图片2将转成 base64 格式 reader.readAsDataURL(file); // 读取成功后的回调 reader.onloadend = function () { let result = this.result; let img = new Image(); img.src = result; //判断图片是否大于100K,是就直接上传,反之压缩图片 if (this.result.length <= (100 * 1024)) { self.headerImage = this.result; self.postImg(); }else { img.onload = function () { let data = self.compress(img,Orientation); self.headerImage = data; self.postImg(); } } } } }, postImg () { //这里写接口 }, rotateImg (img, direction,canvas) { //最小与最大旋转方向,图片旋转4次后回到原方向 const min_step = 0; const max_step = 3; if (img == null)return; //img的高度和宽度不能在img元素隐藏后获取,否则会出错 let height = img.height; let width = img.width; let step = 2; if (step == null) { step = min_step; } if (direction == 'right') { step++; //旋转到原位置,即超过最大值 step > max_step && (step = min_step); } else { step--; step < min_step && (step = max_step); } //旋转角度以弧度值为参数 let degree = step * 90 * Math.PI / 180; let ctx = canvas.getContext('2d'); switch (step) { case 0: canvas.width = width; canvas.height = height; ctx.drawImage(img, 0, 0); break; case 1: canvas.width = height; canvas.height = width; ctx.rotate(degree); ctx.drawImage(img, 0, -height); break; case 2: canvas.width = width; canvas.height = height; ctx.rotate(degree); ctx.drawImage(img, -width, -height); break; case 3: canvas.width = height; canvas.height = width; ctx.rotate(degree); ctx.drawImage(img, -width, 0); break; } }, compress(img,Orientation) { let canvas = document.createElement("canvas"); let ctx = canvas.getContext('2d'); //瓦片canvas let tCanvas = document.createElement("canvas"); let tctx = tCanvas.getContext("2d"); let initSize = img.src.length; let width = img.width; let height = img.height; //如果图片大于四百万像素,计算压缩比并将大小压至400万以下 let ratio; if ((ratio = width * height / 4000000) > 1) { console.log("大于400万像素") ratio = Math.sqrt(ratio); width /= ratio; height /= ratio; } else { ratio = 1; } canvas.width = width; canvas.height = height; // 铺底色 ctx.fillStyle = "#fff"; ctx.fillRect(0, 0, canvas.width, canvas.height); //如果图片像素大于100万则使用瓦片绘制 let count; if ((count = width * height / 1000000) > 1) { console.log("超过100W像素"); count = ~~(Math.sqrt(count) + 1); //计算要分成多少块瓦片 // 计算每块瓦片的宽和高 let nw = ~~(width / count); let nh = ~~(height / count); tCanvas.width = nw; tCanvas.height = nh; for (let i = 0; i < count; i++) { for (let j = 0; j < count; j++) { tctx.drawImage(img, i * nw * ratio, j * nh * ratio, nw * ratio, nh * ratio, 0, 0, nw, nh); ctx.drawImage(tCanvas, i * nw, j * nh, nw, nh); } } } else { ctx.drawImage(img, 0, 0, width, height); } //修复ios上传图片的时候 被旋转的问题 if(Orientation != "" && Orientation != 1){ switch(Orientation){ case 6://需要顺时针(向左)90度旋转 this.rotateImg(img,'left',canvas); break; case 8://需要逆时针(向右)90度旋转 this.rotateImg(img,'right',canvas); break; case 3://需要180度旋转 this.rotateImg(img,'right',canvas);//转两次 this.rotateImg(img,'right',canvas); break; } } //进行最小压缩 let ndata = canvas.toDataURL('image/jpeg', 0.1); console.log('压缩前:' + initSize); console.log('压缩后:' + ndata.length); console.log('压缩率:' + ~~(100 * (initSize - ndata.length) / initSize) + "%"); tCanvas.width = tCanvas.height = canvas.width = canvas.height = 0; return ndata; }, } } </script> <style> *{ margin: 0; padding: 0; } .show { width: 100px; height: 100px; overflow: hidden; position: relative; border-radius: 50%; border: 1px solid #d5d5d5; } .picture { width: 100%; height: 100%; overflow: hidden; background-position: center center; background-repeat: no-repeat; background-size: cover; } </style>
引用的exif.js程式碼
(function() { var debug = false; var root = this; var EXIF = function(obj) { if (obj instanceof EXIF) return obj; if (!(this instanceof EXIF)) return new EXIF(obj); this.EXIFwrapped = obj; }; if (typeof exports !== 'undefined') { if (typeof module !== 'undefined' && module.exports) { exports = module.exports = EXIF; } exports.EXIF = EXIF; } else { root.EXIF = EXIF; } var ExifTags = EXIF.Tags = { // version tags 0x9000 : "ExifVersion", // EXIF version 0xA000 : "FlashpixVersion", // Flashpix format version // colorspace tags 0xA001 : "ColorSpace", // Color space information tag // image configuration 0xA002 : "PixelXDimension", // Valid width of meaningful image 0xA003 : "PixelYDimension", // Valid height of meaningful image 0x9101 : "ComponentsConfiguration", // Information about channels 0x9102 : "CompressedBitsPerPixel", // Compressed bits per pixel // user information 0x927C : "MakerNote", // Any desired information written by the manufacturer 0x9286 : "UserComment", // Comments by user // related file 0xA004 : "RelatedSoundFile", // Name of related sound file // date and time 0x9003 : "DateTimeOriginal", // Date and time when the original image was generated 0x9004 : "DateTimeDigitized", // Date and time when the image was stored digitally 0x9290 : "SubsecTime", // Fractions of seconds for DateTime 0x9291 : "SubsecTimeOriginal", // Fractions of seconds for DateTimeOriginal 0x9292 : "SubsecTimeDigitized", // Fractions of seconds for DateTimeDigitized // picture-taking conditions 0x829A : "ExposureTime", // Exposure time (in seconds) 0x829D : "FNumber", // F number 0x8822 : "ExposureProgram", // Exposure program 0x8824 : "SpectralSensitivity", // Spectral sensitivity 0x8827 : "ISOSpeedRatings", // ISO speed rating 0x8828 : "OECF", // Optoelectric conversion factor 0x9201 : "ShutterSpeedValue", // Shutter speed 0x9202 : "ApertureValue", // Lens aperture 0x9203 : "BrightnessValue", // Value of brightness 0x9204 : "ExposureBias", // Exposure bias 0x9205 : "MaxApertureValue", // Smallest F number of lens 0x9206 : "SubjectDistance", // Distance to subject in meters 0x9207 : "MeteringMode", // Metering mode 0x9208 : "LightSource", // Kind of light source 0x9209 : "Flash", // Flash status 0x9214 : "SubjectArea", // Location and area of main subject 0x920A : "FocalLength", // Focal length of the lens in mm 0xA20B : "FlashEnergy", // Strobe energy in BCPS 0xA20C : "SpatialFrequencyResponse", // 0xA20E : "FocalPlaneXResolution", // Number of pixels in width direction per FocalPlaneResolutionUnit 0xA20F : "FocalPlaneYResolution", // Number of pixels in height direction per FocalPlaneResolutionUnit 0xA210 : "FocalPlaneResolutionUnit", // Unit for measuring FocalPlaneXResolution and FocalPlaneYResolution 0xA214 : "SubjectLocation", // Location of subject in image 0xA215 : "ExposureIndex", // Exposure index selected on camera 0xA217 : "SensingMethod", // Image sensor type 0xA300 : "FileSource", // Image source (3 == DSC) 0xA301 : "SceneType", // Scene type (1 == directly photographed) 0xA302 : "CFAPattern", // Color filter array geometric pattern 0xA401 : "CustomRendered", // Special processing 0xA402 : "ExposureMode", // Exposure mode 0xA403 : "WhiteBalance", // 1 = auto white balance, 2 = manual 0xA404 : "DigitalZoomRation", // Digital zoom ratio 0xA405 : "FocalLengthIn35mmFilm", // Equivalent foacl length assuming 35mm film camera (in mm) 0xA406 : "SceneCaptureType", // Type of scene 0xA407 : "GainControl", // Degree of overall image gain adjustment 0xA408 : "Contrast", // Direction of contrast processing applied by camera 0xA409 : "Saturation", // Direction of saturation processing applied by camera 0xA40A : "Sharpness", // Direction of sharpness processing applied by camera 0xA40B : "DeviceSettingDescription", // 0xA40C : "SubjectDistanceRange", // Distance to subject // other tags 0xA005 : "InteroperabilityIFDPointer", 0xA420 : "ImageUniqueID" // Identifier assigned uniquely to each image }; var TiffTags = EXIF.TiffTags = { 0x0100 : "ImageWidth", 0x0101 : "ImageHeight", 0x8769 : "ExifIFDPointer", 0x8825 : "GPSInfoIFDPointer", 0xA005 : "InteroperabilityIFDPointer", 0x0102 : "BitsPerSample", 0x0103 : "Compression", 0x0106 : "PhotometricInterpretation", 0x0112 : "Orientation", 0x0115 : "SamplesPerPixel", 0x011C : "PlanarConfiguration", 0x0212 : "YCbCrSubSampling", 0x0213 : "YCbCrPositioning", 0x011A : "XResolution", 0x011B : "YResolution", 0x0128 : "ResolutionUnit", 0x0111 : "StripOffsets", 0x0116 : "RowsPerStrip", 0x0117 : "StripByteCounts", 0x0201 : "JPEGInterchangeFormat", 0x0202 : "JPEGInterchangeFormatLength", 0x012D : "TransferFunction", 0x013E : "WhitePoint", 0x013F : "PrimaryChromaticities", 0x0211 : "YCbCrCoefficients", 0x0214 : "ReferenceBlackWhite", 0x0132 : "DateTime", 0x010E : "ImageDescription", 0x010F : "Make", 0x0110 : "Model", 0x0131 : "Software", 0x013B : "Artist", 0x8298 : "Copyright" }; var GPSTags = EXIF.GPSTags = { 0x0000 : "GPSVersionID", 0x0001 : "GPSLatitudeRef", 0x0002 : "GPSLatitude", 0x0003 : "GPSLongitudeRef", 0x0004 : "GPSLongitude", 0x0005 : "GPSAltitudeRef", 0x0006 : "GPSAltitude", 0x0007 : "GPSTimeStamp", 0x0008 : "GPSSatellites", 0x0009 : "GPSStatus", 0x000A : "GPSMeasureMode", 0x000B : "GPSDOP", 0x000C : "GPSSpeedRef", 0x000D : "GPSSpeed", 0x000E : "GPSTrackRef", 0x000F : "GPSTrack", 0x0010 : "GPSImgDirectionRef", 0x0011 : "GPSImgDirection", 0x0012 : "GPSMapDatum", 0x0013 : "GPSDestLatitudeRef", 0x0014 : "GPSDestLatitude", 0x0015 : "GPSDestLongitudeRef", 0x0016 : "GPSDestLongitude", 0x0017 : "GPSDestBearingRef", 0x0018 : "GPSDestBearing", 0x0019 : "GPSDestDistanceRef", 0x001A : "GPSDestDistance", 0x001B : "GPSProcessingMethod", 0x001C : "GPSAreaInformation", 0x001D : "GPSDateStamp", 0x001E : "GPSDifferential" }; var StringValues = EXIF.StringValues = { ExposureProgram : { 0 : "Not defined", 1 : "Manual", 2 : "Normal program", 3 : "Aperture priority", 4 : "Shutter priority", 5 : "Creative program", 6 : "Action program", 7 : "Portrait mode", 8 : "Landscape mode" }, MeteringMode : { 0 : "Unknown", 1 : "Average", 2 : "CenterWeightedAverage", 3 : "Spot", 4 : "MultiSpot", 5 : "Pattern", 6 : "Partial", 255 : "Other" }, LightSource : { 0 : "Unknown", 1 : "Daylight", 2 : "Fluorescent", 3 : "Tungsten (incandescent light)", 4 : "Flash", 9 : "Fine weather", 10 : "Cloudy weather", 11 : "Shade", 12 : "Daylight fluorescent (D 5700 - 7100K)", 13 : "Day white fluorescent (N 4600 - 5400K)", 14 : "Cool white fluorescent (W 3900 - 4500K)", 15 : "White fluorescent (WW 3200 - 3700K)", 17 : "Standard light A", 18 : "Standard light B", 19 : "Standard light C", 20 : "D55", 21 : "D65", 22 : "D75", 23 : "D50", 24 : "ISO studio tungsten", 255 : "Other" }, Flash : { 0x0000 : "Flash did not fire", 0x0001 : "Flash fired", 0x0005 : "Strobe return light not detected", 0x0007 : "Strobe return light detected", 0x0009 : "Flash fired, compulsory flash mode", 0x000D : "Flash fired, compulsory flash mode, return light not detected", 0x000F : "Flash fired, compulsory flash mode, return light detected", 0x0010 : "Flash did not fire, compulsory flash mode", 0x0018 : "Flash did not fire, auto mode", 0x0019 : "Flash fired, auto mode", 0x001D : "Flash fired, auto mode, return light not detected", 0x001F : "Flash fired, auto mode, return light detected", 0x0020 : "No flash function", 0x0041 : "Flash fired, red-eye reduction mode", 0x0045 : "Flash fired, red-eye reduction mode, return light not detected", 0x0047 : "Flash fired, red-eye reduction mode, return light detected", 0x0049 : "Flash fired, compulsory flash mode, red-eye reduction mode", 0x004D : "Flash fired, compulsory flash mode, red-eye reduction mode, return light not detected", 0x004F : "Flash fired, compulsory flash mode, red-eye reduction mode, return light detected", 0x0059 : "Flash fired, auto mode, red-eye reduction mode", 0x005D : "Flash fired, auto mode, return light not detected, red-eye reduction mode", 0x005F : "Flash fired, auto mode, return light detected, red-eye reduction mode" }, SensingMethod : { 1 : "Not defined", 2 : "One-chip color area sensor", 3 : "Two-chip color area sensor", 4 : "Three-chip color area sensor", 5 : "Color sequential area sensor", 7 : "Trilinear sensor", 8 : "Color sequential linear sensor" }, SceneCaptureType : { 0 : "Standard", 1 : "Landscape", 2 : "Portrait", 3 : "Night scene" }, SceneType : { 1 : "Directly photographed" }, CustomRendered : { 0 : "Normal process", 1 : "Custom process" }, WhiteBalance : { 0 : "Auto white balance", 1 : "Manual white balance" }, GainControl : { 0 : "None", 1 : "Low gain up", 2 : "High gain up", 3 : "Low gain down", 4 : "High gain down" }, Contrast : { 0 : "Normal", 1 : "Soft", 2 : "Hard" }, Saturation : { 0 : "Normal", 1 : "Low saturation", 2 : "High saturation" }, Sharpness : { 0 : "Normal", 1 : "Soft", 2 : "Hard" }, SubjectDistanceRange : { 0 : "Unknown", 1 : "Macro", 2 : "Close view", 3 : "Distant view" }, FileSource : { 3 : "DSC" }, Components : { 0 : "", 1 : "Y", 2 : "Cb", 3 : "Cr", 4 : "R", 5 : "G", 6 : "B" } }; function addEvent(element, event, handler) { if (element.addEventListener) { element.addEventListener(event, handler, false); } else if (element.attachEvent) { element.attachEvent("on" + event, handler); } } function imageHasData(img) { return !!(img.exifdata); } function base64ToArrayBuffer(base64, contentType) { contentType = contentType || base64.match(/^data\:([^\;]+)\;base64,/mi)[1] || ''; // e.g. 'data:image/jpeg;base64,...' => 'image/jpeg' base64 = base64.replace(/^data\:([^\;]+)\;base64,/gmi, ''); var binary = atob(base64); var len = binary.length; var buffer = new ArrayBuffer(len); var view = new Uint8Array(buffer); for (var i = 0; i 4 ? valueOffset : (entryOffset + 8); vals = []; for (n=0;n<numvalues> 4 ? valueOffset : (entryOffset + 8); return getStringFromDB(file, offset, numValues-1); case 3: // short, 16 bit int if (numValues == 1) { return file.getUint16(entryOffset + 8, !bigEnd); } else { offset = numValues > 2 ? valueOffset : (entryOffset + 8); vals = []; for (n=0;n<numvalues><p>相信看了本文案例你已經掌握了方法,更多精彩請關注php中文網其它相關文章! </p> <p>推薦閱讀:</p> <p style="text-align: left;"><a href="http://www.php.cn/js-tutorial-396234.html" target="_blank">layui動態與靜態分頁實作步驟詳解</a><br></p> <p style="text-align: left;"><a href="http://www.php.cn/js-tutorial-396233.html" target="_blank">vue彈窗訊息元件使用步驟詳解</a><br></p> <p style="text-align: left;"><a href="http://www.php.cn/js-tutorial-396224.html" target="_blank">vue jquery lodash滑動時頂部懸浮固定功能實作詳解</a><br></p>#</numvalues></numvalues>
以上是vue2.0調用攝影機步驟詳解的詳細內容。更多資訊請關注PHP中文網其他相關文章!

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