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js插件---图片裁剪cropImgBox（适合练习编写插件之用）

一、总结

一句话总结：无论是灰度还是高对比度的图片，都是先处理canvas的像素，使其变成灰度或者高对比度，然后再用canvas.toDataURL('image/png');输出出来

1、img获取图片来源的两种方式是什么？

a、src直接接图片地址

b、src接图片base64格式数据

<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAMYAAADGCAYAAACJmedZ42w6ICXmpjvKovOPKYwGVmCsB8xsp+rpF01eCriAy7eYqpTYtCXF8P43revYrfaxf8CrXnKcdq0FW0AAAAASUVORK5CYII=" align="absmiddle" style="128px;margin-top:4px;border-radius:128px;box-shadow:0px 0px 12px #7E7E7E;">

2、图片裁剪好的canvas是怎么输出图片数据的？

无论是灰度还是高对比度的图片，都是先处理canvas的像素，使其变成灰度或者高对比度，然后再用canvas.toDataURL('image/png');输出出来

 1 var arr_result = [], arr = obj.clipType.split('|');
 2 
 3 var context = canvas.getContext("2d");
 4 context.drawImage(this.image, 0, 0, sw, sh, dx, dy, dw, dh);
 5 var imageData = canvas.toDataURL('image/png');
 6 arr_result.push(imageData);
 7 
 8 var _param = 0, key = '';
 9 if (arr.length > 1 && arr[1] == '1') {
10     context.clearRect(0, 0, 10000, 10000);
11     key = 'gray';
12     var imgToGray = imgTrans(canvas, imageData, key, function () {
13         _param += 1;
14         imageData = canvas.toDataURL('image/png');
15         arr_result.push(imageData);
16     });
17 }
18 if (arr.length > 2 && arr[2] == '1') {
19     context.clearRect(0, 0, 10000, 10000);
20     key = 'bright';
21     var imgToGray = imgTrans(canvas, imageData, key, function () {
22         _param += 1;
23         imageData = canvas.toDataURL('image/png');
24         arr_result.push(imageData);
25     });
26 }

二、图片裁剪cropImgBox（适合练习）

百度盘下载地址：

链接：https://pan.baidu.com/s/1_gSUaEX23_b73tqHV0FwFQ 密码：1124

1、截图

2、代码

index.html

 1 <!DOCTYPE html>
 2 <html xmlns="http://www.w3.org/1999/xhtml">
 3 <head>
 4     <meta charset="utf-8">
 5     <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
 6     <meta name="description" content="图片裁剪并设置效果插件，暂时只设置了几种效果，后面会加更多效果，敬请期待...">
 7     <meta name="keywords" content="图片裁剪，crop,Image">
 8     <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
 9     <title>Amaze UI CorpImgBox</title>
10     <meta name="renderer" content="webkit">
11     <meta http-equiv="Cache-Control" content="no-siteapp" />
12     <link href="amazeui.css" rel="stylesheet" />
13     <link href="amazeui.cropimgbox.min.css" rel="stylesheet" />
14     <script type="text/javascript" src="jquery.min.js"></script>
15     <script src="cropimgbox.js"></script>
16     <script type="text/javascript">
17         (function ($) {
18             $(function () {
19                 var options =
20                     {
21                         thumbBox: '.cropimgbox-thumbBox',
22                         spinner: '.cropimgbox-spinner',
23                         imgSrc: ''
24                     }
25                 var cropper = $('.cropimgbox-imageBox').cropimgbox(options);
26                 var img = "";
27 
28                 $(document).on('change', '#upload-file', function () {
29                     var reader = new FileReader();
30                     reader.onload = function (e) {
31                         options.imgSrc = e.target.result;
32                         cropper = $('.cropimgbox-imageBox').cropimgbox(options);
33                         getImg();
34                     }
35                     reader.readAsDataURL(this.files[0]);
36                     this.files.length = 0;
37                 })
38                 .on('mouseup','.cropimgbox-imageBox', function () {
39                     getImg();
40                 })
41                 .on('click','#btnZoomIn', function () {
42                     cropper.zoomIn();
43                     cropper.getBlob
44                 })
45                 .on('click','#btnZoomOut', function () {
46                     cropper.zoomOut();
47                 })
48 
49                 function getImg() {
50                     cropper.getDataURL(function (imgs) {
51                         $('.cropimgbox-cropped').html('');
52                         $('.cropimgbox-cropped').append('<img src="' + imgs[0] + '" align="absmiddle" style="128px;margin-top:4px;border-radius:128px;box-shadow:0px 0px 12px #7E7E7E;"><p>原图</p>');
53                         $('.cropimgbox-cropped').append('<img src="' + imgs[1] + '" align="absmiddle" style="128px;margin-top:4px;border-radius:128px;box-shadow:0px 0px 12px #7E7E7E;"><p>灰化</p>');
54                         $('.cropimgbox-cropped').append('<img src="' + imgs[2] + '" align="absmiddle" style="128px;margin-top:4px;border-radius:128px;box-shadow:0px 0px 12px #7E7E7E;"><p>高亮高对比</p>');
55                     });
56                 }
57             })
58         })(jQuery);
59     </script>
60 </head>
61 <body>
62     <div class="cropimgbox">
63         <div class="cropimgbox-imageBox">
64             <div class="cropimgbox-thumbBox"></div>
65             <div class="cropimgbox-spinner" style="display: none"></div>
66         </div>
67 
68         <div class="cropimgbox-action">
69             <div class="am-btn-group am-btn-group-xs">
70                 <button type="button" id="btnZoomIn" class="am-btn am-btn-default am-btn-xs am-text-secondary"><span class="am-icon-plus"></span> 放大</button>
71                 <button type="button" id="btnZoomOut" class="am-btn am-btn-default am-btn-xs am-text-secondary"><span class="am-icon-minus"></span> 缩小</button>
72             </div>
73             <div class="cropimgbox-contentarea">
74                 <a href="javascript:void(0)" class="cropimgbox-upload-img">
75                     <label for="cropimgbox-upload-file">选择图片...</label>
76                 </a>
77                 <input type="file" class="" name="cropimgbox-upload-file" id="upload-file" />
78             </div>
79         </div>
80         <div class="cropimgbox-cropped"></div>
81     </div>
82 </body>
83 </html>

cropimgbox.js

  1 /*
  2  cropimgbox.js
  3  ------------------------------------------------------------
  4  |  Note:暂时提供了除原图外的2种效果（灰化、高亮高对比），可通过修改
  5  |  cvtColor、brightnessContrast函数在此基础上渐变多种效果。
  6  -------------------------------------------------------------
  7  *********注：基于cropbox修改 https://github.com/hongkhanh/cropbox *************
  8  Version: 1.0.0
  9  Author: lazyperson
 10  QQ: 564981089
 11  Website: https://github.com/lazyperson
 12  */
 13 (function (factory) {
 14     'use strict';
 15     if (typeof define === 'function' && define.amd) {
 16         define(['jquery'], factory);
 17     } else if (typeof exports !== 'undefined') {
 18         module.exports = factory(require('jquery'));
 19     } else {
 20         factory(jQuery);
 21     }
 22 }(function ($) {
 23     "use strict";
 24     var cropimgbox = function (options, el) {
 25         options.expandRatio = options.expandRatio || 1.1;
 26         options.narrowRatio = options.narrowRatio || 0.9;
 27         var el = el || $(options.imageBox),
 28             obj =
 29             {
 30                 state: {},
 31                 ratio: 1,
 32                 //clipType：裁剪后得到的效果图类型，1显示，0不显示。表示类型依次为 原图（必须有）|灰白图|高亮对比图
 33                 clipType: '1|1|1',
 34                 options: options,
 35                 imageBox: el,
 36                 thumbBox: el.find(options.thumbBox),
 37                 spinner: el.find(options.spinner),
 38                 image: new Image(),
 39                 getDataURL: function (callfun) {
 40                     var width = this.thumbBox.width(),
 41                         height = this.thumbBox.height(),
 42                         canvas = document.createElement("canvas"),
 43                         dim = el.css('background-position').split(' '),
 44                         size = el.css('background-size').split(' '),
 45                         dx = parseInt(dim[0]) - el.width() / 2 + width / 2,
 46                         dy = parseInt(dim[1]) - el.height() / 2 + height / 2,
 47                         dw = parseInt(size[0]),
 48                         dh = parseInt(size[1]),
 49                         sh = parseInt(this.image.height),
 50                         sw = parseInt(this.image.width);
 51 
 52                     canvas.width = width;
 53                     canvas.height = height;
 54 
 55                     var arr_result = [], arr = obj.clipType.split('|');
 56 
 57                     var context = canvas.getContext("2d");
 58                     context.drawImage(this.image, 0, 0, sw, sh, dx, dy, dw, dh);
 59                     var imageData = canvas.toDataURL('image/png');
 60                     arr_result.push(imageData);
 61 
 62                     var _param = 0, key = '';
 63                     if (arr.length > 1 && arr[1] == '1') {
 64                         context.clearRect(0, 0, 10000, 10000);
 65                         key = 'gray';
 66                         var imgToGray = imgTrans(canvas, imageData, key, function () {
 67                             _param += 1;
 68                             imageData = canvas.toDataURL('image/png');
 69                             arr_result.push(imageData);
 70                         });
 71                     }
 72                     if (arr.length > 2 && arr[2] == '1') {
 73                         context.clearRect(0, 0, 10000, 10000);
 74                         key = 'bright';
 75                         var imgToGray = imgTrans(canvas, imageData, key, function () {
 76                             _param += 1;
 77                             imageData = canvas.toDataURL('image/png');
 78                             arr_result.push(imageData);
 79                         });
 80                     }
 81 
 82 
 83                     function imgTrans(iCanvas, url, key, callback) {
 84                         var _th = this;
 85                         var canvas = iCanvas,
 86                         iCtx = canvas.getContext("2d"),
 87                         url = url;
 88 
 89                         var imread = function (_image) {
 90                             var width = _image.width,
 91                                 height = _image.height;
 92                             iResize(width, height);
 93                             iCtx.drawImage(_image, 0, 0);
 94                             var imageData = iCtx.getImageData(0, 0, width, height),
 95                                 tempMat = new Mat(height, width, imageData.data);
 96                             imageData = null;
 97                             iCtx.clearRect(0, 0, width, height);
 98                             return tempMat;
 99                         },
100                         iResize = function (_width, _height) {
101                             canvas.width = _width;
102                             canvas.height = _height;
103                         },
104                         RGBA2ImageData = function (_imgMat) {
105                             var width = _imgMat.col,
106                                 height = _imgMat.row,
107                                 imageData = iCtx.createImageData(width, height);
108                             imageData.data.set(_imgMat.data);
109                             return imageData;
110                         },
111                         render = function (key, callback) {
112                             var img = new Image();
113                             img.onload = function () {
114                                 var myMat = imread(img);
115                                 if (key == 'gray') {
116                                     var newImage = cvtColor(myMat, "CV_RGBA");
117                                     var newIamgeData = RGBA2ImageData(newImage);
118                                     iCtx.putImageData(newIamgeData, 0, 0);
119                                 }
120                                 if (key == 'bright') {
121                                     var newImage = brightnessContrast(myMat, 50, 50);
122                                     var newIamgeData = RGBA2ImageData(newImage);
123                                     iCtx.putImageData(newIamgeData, 0, 0);
124                                 }
125                                 callback();
126                             };
127                             img.src = url;
128                         };
129 
130                         render(key, callback);
131                     }
132 
133 
134                     function Mat(_row, _col, _data, _buffer) {
135                         this.row = _row || 0;
136                         this.col = _col || 0;
137                         this.channel = 4;
138                         this.buffer = _buffer || new ArrayBuffer(_row * _col * 4);
139                         this.data = new Uint8ClampedArray(this.buffer);
140                         _data && this.data.set(_data);
141                         this.bytes = 1;
142                         this.type = "CV_RGBA";
143                     }
144 
145                     function cvtColor(_src, _code) {
146                         var row = _src.row,
147                             col = _src.col;
148                         if (_src.type && _code === "CV_RGBA") {
149                             var dst = new Mat(row, col),
150                             data = dst.data,
151                             data2 = _src.data;
152                             var pix1, pix2, pix = _src.row * _src.col * 4;
153                             while (pix) {
154                                 data[pix -= 4] = data[pix1 = pix + 1] = data[pix2 = pix + 2] = (data2[pix] * 299 + data2[pix1] * 587 + data2[pix2] * 114) / 1000;
155                                 data[pix + 3] = data2[pix + 3];
156                             }
157                         } else if (_src.type && _code === "CV_RGBA2GRAY") {
158                             var dst = new Mat(row, col),
159                                     data = dst.data,
160                                     data2 = _src.data;
161                             var pix = row * col;
162                             while (pix) {
163                                 data[--pix] = (data2[4 * pix] * 9798 + data2[4 * pix + 1] * 19235 + data2[4 * pix + 2] * 3736) >> 15;
164                             }
165                         }
166                         return dst;
167                     }
168 
169                     var brightnessContrast = function (__src, __brightness, __contrast) {
170                         if (__src.type === "CV_RGBA") {
171                             var sData = __src.data,
172                                 width = __src.col,
173                                 height = __src.row,
174                                 dst = new Mat(height, width);
175                             var dData = dst.data,
176                              brightness = Math.max(-255, Math.min(255, __brightness || 0)),
177                              contrast = Math.max(-255, Math.min(255, __contrast || 0));
178 
179                             var gray = cvtColor(__src, "CV_RGBA2GRAY", 2),
180                                 allValue = 0,
181                                 gData = gray.data;
182                             var y, x, c;
183 
184                             for (y = height; y--;) {
185                                 for (x = width; x--;) {
186                                     allValue += gData[y * width + x];
187                                 }
188                             }
189 
190                             var r, g, b, offset, gAverage = (allValue / (height * width)) | 0;
191 
192                             for (y = height; y--;) {
193                                 for (x = width; x--;) {
194                                     offset = (y * width + x) * 4;
195                                     dData[offset] = sData[offset] + brightness;
196                                     dData[offset + 1] = sData[offset + 1] + brightness;
197                                     dData[offset + 2] = sData[offset + 2] + brightness;
198 
199                                     if (contrast >= 0) {
200                                         for (c = 3; c--;) {
201                                             if (dData[offset + c] >= gAverage) {
202                                                 dData[offset + c] = dData[offset + c] + (255 - gAverage) * contrast / 255;
203                                             } else {
204                                                 dData[offset + c] = dData[offset + c] - (gAverage * contrast / 255);
205                                             }
206                                         }
207                                     } else {
208                                         dData[offset] = dData[offset] + (dData[offset] - gAverage) * contrast / 255;
209                                         dData[offset + 1] = dData[offset + 1] + (dData[offset + 1] - gAverage) * contrast / 255;
210                                         dData[offset + 2] = dData[offset + 2] + (dData[offset + 2] - gAverage) * contrast / 255;
211                                     }
212                                     dData[offset + 3] = 255;
213                                 }
214                             }
215                         }
216                         return dst;
217                     };
218 
219                     var num = arr.length > 1 && arr[1] == '1' || arr.length > 2 && arr[2] == '1' ? (arr.length > 1 && arr[1] == '1' && arr.length > 2 && arr[2] == '1' ? 2 : 1) : 0;
220                     if (arr.length > 1 && arr[1] == '1' || arr.length > 2 && arr[2] == '1') {
221                         if (_param > 0)
222                             return arr_result;
223                         else {
224                             (function func() {
225                                 if (_param >= num) {
226                                     _param = 0;
227                                     callfun(arr_result);
228                                 }
229                                 else
230                                     setTimeout(func, 500);
231                             })();
232                         }
233                     }
234                 },
235                 getBlob: function (i) {
236                     var imageData = this.getDataURL()[i];
237                     var b64 = imageData.replace('data:image/png;base64,', '');
238                     var binary = atob(b64);
239                     var array = [];
240                     for (var i = 0; i < binary.length; i++) {
241                         array.push(binary.charCodeAt(i));
242                     }
243                     return new Blob([new Uint8Array(array)], { type: 'image/png' });
244                 },
245                 zoomIn: function () {
246                     this.ratio *= options.expandRatio;
247                     setBackground();
248                 },
249                 zoomOut: function () {
250                     this.ratio *= options.narrowRatio;
251                     setBackground();
252                 }
253             },
254             setBackground = function () {
255                 var w = parseInt(obj.image.width) * obj.ratio;
256                 var h = parseInt(obj.image.height) * obj.ratio;
257 
258                 var pw = (el.width() - w) / 2;
259                 var ph = (el.height() - h) / 2;
260                 el.css({
261                     'background-image': 'url(' + obj.image.src + ')',
262                     'background-size': w + 'px ' + h + 'px',
263                     'background-position': pw + 'px ' + ph + 'px',
264                     'background-repeat': 'no-repeat'
265                 });
266             },
267             imgMouseDown = function (e) {
268                 e.stopImmediatePropagation();
269 
270                 obj.state.dragable = true;
271                 obj.state.mouseX = e.clientX;
272                 obj.state.mouseY = e.clientY;
273             },
274             imgMouseMove = function (e) {
275                 e.stopImmediatePropagation();
276 
277                 if (obj.state.dragable) {
278                     var x = e.clientX - obj.state.mouseX;
279                     var y = e.clientY - obj.state.mouseY;
280 
281                     var bg = el.css('background-position').split(' ');
282 
283                     var bgX = x + parseInt(bg[0]);
284                     var bgY = y + parseInt(bg[1]);
285 
286                     el.css('background-position', bgX + 'px ' + bgY + 'px');
287 
288                     obj.state.mouseX = e.clientX;
289                     obj.state.mouseY = e.clientY;
290                 }
291             },
292             imgMouseUp = function (e) {
293                 e.stopImmediatePropagation();
294                 obj.state.dragable = false;
295             },
296             zoomImage = function (e) {
297                 e.originalEvent.wheelDelta > 0 || e.originalEvent.detail < 0 ? obj.ratio *= options.expandRatio : obj.ratio *=options.narrowRatio;
298                 setBackground();
299             }
300 
301         obj.spinner.show();
302 
303         obj.image.onload = function () {
304             obj.spinner.hide();
305             setBackground();
306             el.bind('mousedown', imgMouseDown);
307             el.bind('mousemove', imgMouseMove);
308             $(window).bind('mouseup', imgMouseUp);
309             el.bind('mousewheel DOMMouseScroll', zoomImage);
310         };
311 
312         obj.image.src = options.imgSrc;
313         el.on('remove', function () { $(window).unbind('mouseup', imgMouseUp) });
314 
315         return obj;
316     };
317 
318     jQuery.fn.cropimgbox = function (options) {
319         return new cropimgbox(options, this);
320     };
321 }));

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原文地址：https://www.cnblogs.com/Renyi-Fan/p/9591364.html