NodeJS实现图片文本分割

本文实例为大家分享了nodejs实现图片文本分割的具体代码，供大家参考，具体内容如下

var fs = require('fs');
var jpeg = require('jpeg-js')
 
 
function getsumrgb(data, i)
{
 var cr = data.data[i+0]
 var cg = data.data[i+1]
 var cb = data.data[i+2]
 var srgb = (cr+cg+cb)
 return srgb
}
 
function gettoprgb(data, i)
{
 var topindex = (data.width * 4 * -1)
 i= i + topindex;
 var cr = data.data[i+0]
 var cg = data.data[i+1]
 var cb = data.data[i+2]
 
 return [cr,cg,cb]
}
 
function getheightrgb(data, i, havergb)
{
 var width = data.width
 var height = data.height
 var len = width * height * 4
 var havenum = 0
 
 for(i=i;i<len;i+=width*4)
 {
  if(getsumrgb(data, i) == havergb)
  {
   havenum++
  }
 }
 
 return havenum
}
 
function clearbackground(data)
{ 
 var width = data.width
 var height = data.height
 var len = width * height * 4
 var i, tmp
 for(i=0;i<len;i+=4) 
 {
  tmp = getsumrgb(data, i)
  if(tmp > 120*3) {
   data.data[i+0]=255
   data.data[i+1]=255
   data.data[i+2]=255
  }
 }
 
 for(i=0;i<len;i+=4)
 {
  tmp = getsumrgb(data, i)
  if(tmp <= 32*3) {
   tmp = gettoprgb(data, i)
   data.data[i+0]=tmp[0]
   data.data[i+1]=tmp[1]
   data.data[i+2]=tmp[2]
  }
 }
 
 for(i=0;i<len;i+=4)
 {
  tmp = getsumrgb(data, i)
  if(tmp !=255*3) {
   data.data[i+0]=0
   data.data[i+1]=0
   data.data[i+2]=0
  }
 }
 
 var maxwidth  = width * 4
 var arrlist = []
 arrlist[0]=[]
 arrlist[1]=[]
 arrlist[2]=[]
 arrlist[3]=[]
 arrnum = 0
 block = 0
 
 for(i=0;i<maxwidth;i+=4)
 {
  tmp= getheightrgb(data, i, 0)
  if(tmp==0) {
   if(block != 0) {
    arrlist[arrnum] = [block/4,i/4]
    block=0
    arrnum++
   }
  } else if(tmp >0 ) {
   if(block == 0) {
    block = i
   }
  }
 }
 
 console.log(arrlist)
 
 return data
}
 
 
var picname = "tmp.jpg"
var newpicname= "000.jpg"
var jpegdata = fs.readfilesync(picname)
var rawimagedata = jpeg.decode(jpegdata, {usetarray: true})
rawimagedata = clearbackground(rawimagedata)
var jpegimagedata = jpeg.encode(rawimagedata,100)
fs.writefilesync(newpicname, jpegimagedata.data)

再为大家分享js实现图片切割的方法：

//图片切割
var imgcropper = class.create();
imgcropper.prototype = {
  //容器对象,控制层,图片地址
  initialize: function(container, handle, url, options) {
    this._container = $(container);//容器对象
    this._layhandle = $(handle);//控制层
    this.url = url;//图片地址
    
    this._laybase = this._container.appendchild(document.createelement("img"));//底层
    this._laycropper = this._container.appendchild(document.createelement("img"));//切割层
    this._laycropper.onload = bind(this, this.setpos);
    //用来设置大小
    this._tempimg = document.createelement("img");
    this._tempimg.onload = bind(this, this.setsize);
    
    this.setoptions(options);
    
    this.opacity = math.round(this.options.opacity);
    this.color = this.options.color;
    this.scale = !!this.options.scale;
    this.ratio = math.max(this.options.ratio, 0);
    this.width = math.round(this.options.width);
    this.height = math.round(this.options.height);
    
    //设置预览对象
    var opreview = $(this.options.preview);//预览对象
    if(opreview){
        opreview.style.position = "relative";
        opreview.style.overflow = "hidden";
        this.viewwidth = math.round(this.options.viewwidth);
        this.viewheight = math.round(this.options.viewheight);
        //预览图片对象
        this._view = opreview.appendchild(document.createelement("img"));
        this._view.style.position = "absolute";
        this._view.onload = bind(this, this.setpreview);
    }
    //设置拖放
    this._drag = new drag(this._layhandle, { limit: true, onmove: bind(this, this.setpos), transparent: true });
    //设置缩放
    this.resize = !!this.options.resize;
    if(this.resize){
        var op = this.options, _resize = new resize(this._layhandle, { max: true, onresize: bind(this, this.setpos) });
        //设置缩放触发对象
        op.rightdown && (_resize.set(op.rightdown, "right-down"));
        op.leftdown && (_resize.set(op.leftdown, "left-down"));
        op.rightup && (_resize.set(op.rightup, "right-up"));
        op.leftup && (_resize.set(op.leftup, "left-up"));
        op.right && (_resize.set(op.right, "right"));
        op.left && (_resize.set(op.left, "left"));
        op.down && (_resize.set(op.down, "down"));
        op.up && (_resize.set(op.up, "up"));
        //最小范围限制
        this.min = !!this.options.min;
        this.minwidth = math.round(this.options.minwidth);
        this.minheight = math.round(this.options.minheight);
        //设置缩放对象
        this._resize = _resize;
    }
    //设置样式
    this._container.style.position = "relative";
    this._container.style.overflow = "hidden";
    this._layhandle.style.zindex = 200;
    this._laycropper.style.zindex = 100;
    this._laybase.style.position = this._laycropper.style.position = "absolute";
    this._laybase.style.top = this._laybase.style.left = this._laycropper.style.top = this._laycropper.style.left = 0;//对齐
    //初始化设置
    this.init();
  },
  //设置默认属性
  setoptions: function(options) {
    this.options = {//默认值
        opacity:    50,//透明度(0到100)
        color:        "",//背景色
        width:        0,//图片高度
        height:        0,//图片高度
        //缩放触发对象
        resize:        false,//是否设置缩放
        right:        "",//右边缩放对象
        left:        "",//左边缩放对象
        up:            "",//上边缩放对象
        down:        "",//下边缩放对象
        rightdown:    "",//右下缩放对象
        leftdown:    "",//左下缩放对象
        rightup:    "",//右上缩放对象
        leftup:        "",//左上缩放对象
        min:        false,//是否最小宽高限制(为true时下面min参数有用)
        minwidth:    50,//最小宽度
        minheight:    50,//最小高度
        scale:        false,//是否按比例缩放
        ratio:        0,//缩放比例(宽/高)
        //预览对象设置
        preview:    "",//预览对象
        viewwidth:    0,//预览宽度
        viewheight:    0//预览高度
    };
    extend(this.options, options || {});
  },
  //初始化对象
  init: function() {
    //设置背景色
    this.color && (this._container.style.backgroundcolor = this.color);
    //设置图片
    this._tempimg.src = this._laybase.src = this._laycropper.src = this.url;
    //设置透明
    if(isie){
        this._laybase.style.filter = "alpha(opacity:" + this.opacity + ")";
    } else {
        this._laybase.style.opacity = this.opacity / 100;
    }
    //设置预览对象
    this._view && (this._view.src = this.url);
    //设置缩放
    if(this.resize){
        with(this._resize){
            scale = this.scale; ratio = this.ratio; min = this.min; minwidth = this.minwidth; minheight = this.minheight;
        }
    }
  },
  //设置切割样式
  setpos: function() {
    //ie6渲染bug
    if(isie6){ with(this._layhandle.style){ zoom = .9; zoom = 1; }; };
    //获取位置参数
    var p = this.getpos();
    //按拖放对象的参数进行切割
    this._laycropper.style.clip = "rect(" + p.top + "px " + (p.left + p.width) + "px " + (p.top + p.height) + "px " + p.left + "px)";
    //设置预览
    this.setpreview();
  },
  //设置预览效果
  setpreview: function() {
    if(this._view){
        //预览显示的宽和高
        var p = this.getpos(), s = this.getsize(p.width, p.height, this.viewwidth, this.viewheight), scale = s.height / p.height;
        //按比例设置参数
        var pheight = this._laybase.height * scale, pwidth = this._laybase.width * scale, ptop = p.top * scale, pleft = p.left * scale;
        //设置预览对象
        with(this._view.style){
            //设置样式
            width = pwidth + "px"; height = pheight + "px"; top = - ptop + "px "; left = - pleft + "px";
            //切割预览图
            clip = "rect(" + ptop + "px " + (pleft + s.width) + "px " + (ptop + s.height) + "px " + pleft + "px)";
        }
    }
  },
  //设置图片大小
  setsize: function() {
    var s = this.getsize(this._tempimg.width, this._tempimg.height, this.width, this.height);
    //设置底图和切割图
    this._laybase.style.width = this._laycropper.style.width = s.width + "px";
    this._laybase.style.height = this._laycropper.style.height = s.height + "px";
    //设置拖放范围
    this._drag.mxright = s.width; this._drag.mxbottom = s.height;
    //设置缩放范围
    if(this.resize){ this._resize.mxright = s.width; this._resize.mxbottom = s.height; }
  },
  //获取当前样式
  getpos: function() {
    with(this._layhandle){
        return { top: offsettop, left: offsetleft, width: offsetwidth, height: offsetheight }
    }
  },
  //获取尺寸
  getsize: function(nowwidth, nowheight, fixwidth, fixheight) {
    var iwidth = nowwidth, iheight = nowheight, scale = iwidth / iheight;
    //按比例设置
    if(fixheight){ iwidth = (iheight = fixheight) * scale; }
    if(fixwidth && (!fixheight || iwidth > fixwidth)){ iheight = (iwidth = fixwidth) / scale; }
    //返回尺寸对象
    return { width: iwidth, height: iheight }
  }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。