常用图片处理技巧

1，掉链级图片的替代图片

<img src="no.jpg" onerror="this.src='images/logo.gif'">  [Ctrl+A 全选,提示:你可修改代码后运行]

2，自动缩小大图

经常看到一些图片很大，上传后显示会撑满屏幕
下面的例子通过检测
if(this.width>screen.width-350)then(this.width=screen.width-350)
如果该图片的宽度大于“屏幕宽度-350”，则让该图就显示“屏幕宽度-350”这么大小。

原图<br> <img src="jsimg/wallpaper.jpg"><br> 设定大小的图<br> <img src="jsimg/wallpaper.jpg" onload="javascript:if(this.width>screen.width-350)this.width=screen.width-350">  [Ctrl+A 全选,提示:你可修改代码后运行]

3，禁止IE6中大尺寸图片的自动缩小

原图,会自动缩小<br> <img src="jsimg/wallpaper.jpg"> <br> 设定不缩小<br> <img src="jsimg/wallpaper.jpg" galleryimg="no">  [Ctrl+A 全选,提示:你可修改代码后运行]

4，去掉用IE6.0浏览图片，当鼠标放到图片上时出现快捷工具（打印、邮寄、另存等）

方法一：
<META HTTP-EQUIV="imagetoolbar" CONTENT="no">
方法二：
<img galleryimg="no">
定义CSS：
<style>
img {nobar:expression(this.galleryImg='no')}
</style>

5，去掉热点地图上的区域线框与超链接的线框

<a href="#" onFocus=this.blur()><img src="jsimg/marylin.jpg" border=0></a>  [Ctrl+A 全选,提示:你可修改代码后运行]

6,可控制上传图片的大小

<script language="JavaScript"> function orsc() { if(img.readyState!="complete")return false; if(img.offsetWidth!=132&&img.offsetHeight!=99){ alert("您选择的图片大小："+img.offsetWidth+"X"+img.offsetHeight+"/n"+"请选择132X99大小的图片") imgT=true; } //alert("图片大小："+img.offsetWidth+"X"+img.offsetHeight); //alert("图片尺寸："+img.fileSize); } function mysubmit(theform) { if(theform.file1.value=="") { alert("请点击浏览按钮，选择您要上传的JPG或GIF文件!") theform.file1.focus; return (false); } else { str= theform.file1.value; strs=str.toLowerCase(); lens=strs.length; extname=strs.substring(lens-4,lens); if(extname!=".jpg" && extname!=".gif") { alert("请选择JPG或GIF格式的文件!"); return (false); }else{ document.all("loadImg").src=theform.file1.value if(document.all("loadImg").offsetWidth!=132&&document.all("loadImg").offsetHeight!=99){ alert("您选择的图片大小："+document.all("loadImg").offsetWidth+"X"+document.all("loadImg").offsetHeight+"/n"+"请选择132X99大小的图片") return (false) } } } } </script> <form onSubmit="return mysubmit(this)" name="form" method="post" enctype="multipart/form-data"> <table width="100%" border=0 cellspacing=0 cellpadding=0> <tr><td valign=top height=30> <input type="hidden" name="act" value="upload"> <input type="file" style="BORDER-TOP-WIDTH: 1px; BORDER-LEFT-WIDTH: 1px; FONT-SIZE: 12px; BORDER-BOTTOM-WIDTH: 1px; CURSOR: text; COLOR: #333333; FONT-FAMILY: "MS Shell Dlg", ","Tahoma", ","宋体"; HEIGHT: 20px; BORDER-RIGHT-WIDTH: 1px " name="file1" value=""> <input type="submit" name="Submit" value="上传" > </td> </tr> </table> <img id=loadImg> </form>  [Ctrl+A 全选,提示:你可修改代码后运行]

7,检测一个图片的长宽尺寸

<script> var img=null; function s() { if(img)img.removeNode(true); img=document.createElement("img"); img.style.position="absolute"; img.style.visibility="hidden"; img.attachEvent("onreadystatechange",orsc); img.attachEvent("onerror",oe); document.body.insertAdjacentElement("beforeend",img); img.src=inp.value; } function oe() { alert("cant load img"); } function orsc() { if(img.readyState!="complete")return false; alert("高:"+img.offsetHeight+"/n宽:"+img.offsetWidth); } </script> <input type="file" Name="file" id="inp" value="默认值"><br><input onclick="s()" type="button" value="点我一下给出要上传图片的大小及长、宽" name="button">  [Ctrl+A 全选,提示:你可修改代码后运行]

8,按比例缩小

<script defer> for (var i=0;i<document.images.length;i++){ document.images[i].width=document.images[i].width*0.5 } </script> <img src="jsimg/wallpaper.jpg">  [Ctrl+A 全选,提示:你可修改代码后运行]

9,类似Acdsee看大图的时的拖动

<html> <head> <title>Untitled Document</title> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <script language="JavaScript"> <!-- var scrollcount=0; var dragy; var scrollarrowtop; function initdrag() { scrollcount=1; dragy=event.clientY; document.body.setCapture(); } function startdrag() { if (scrollcount==1) { window.scrollBy(dragy-event.clientX,dragy-event.clientY); document.body.style.cursor='hand'; dragy=event.clientY; } } function enddrag() { document.body.style.cursor=''; scrollcount=0; document.body.releaseCapture(); } // --> </script> </head> <body bgcolor="#FFFFFF" text="#000000" onselectstart="return false;" onmousedown="initdrag()" onmousemove="startdrag()" onmouseup="enddrag()" scroll=yes> <img src="jsimg/wallpaper.jpg"> <img src="jsimg/whitney.jpg"> </body> </html>  [Ctrl+A 全选,提示:你可修改代码后运行]

10,选择图片产生缩略图，最多10个

<html> <head> <title>Upload Image</title> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <SCRIPT language=Javascript> gFlag=false; var gMaxSize,gCurrentSize,gUploadSize,gCurInputIndex,gCurImageSrc,gCurOFile; gMaxSize="10"; gCurrentSize=".18"; gMaxSize=parseFloat(gMaxSize)*1024*1024; //gMaxSize=parseFloat("1")*1024; gCurrentSize=parseFloat(gCurrentSize)*1024*1024; gErr=""; gUploadSize=0; //////////////////////////////////////////////////// function validate() { var lErr; lErr=""; if((gUploadSize+gCurrentSize)>gMaxSize){ if(form1.TempAlbum.value!=form1.OldAlbum.value){ lErr=".您要上传的图片尺寸大于您的剩余相册容量,请选择上传至/"临时相册/"/n"+lErr; } } if(form1.OldAlbum.value=="0"){ if(form1.NewAlbum.value.length==0){ lErr=".请输入新相册名称/n"+lErr; } } if(lErr.length>0){ alert("错误:/n"+lErr); if(lErr.indexOf("请输入新相册名称/n/n")!=-1){ form1.NewAlbum.focus(); } return false; } form1.submit(); /*进度条控制*/ //var winProgress=window.open("progress.htm","progress","width=300,height=250"); //winProgress.focus(); /*进度条控制*/ return true; } function handleBadImage() { alert('所选图片并非有效的JPG格式!/n请重新选择!'); eval("form1.file"+gCurInputIndex+".outerHTML=/"<input type=///"file///" name=///"file"+gCurInputIndex+"///" style=///"width:275///" value=///"///" onChange=///"FileChange(this);///">/""); eval("form1.file"+gCurInputIndex+".fireEvent(/"onChange/")"); return false; } function handleGoodImage() { imgsrc='<img src="'+gCurImageSrc+'" onload="DrawImage(this,'+gCurInputIndex+'); " width="0" height="0">'; gCurOFile.parentNode.previousSibling.innerHTML=imgsrc; return true; } ////////////////////////////////////////// function FileChange(oFile){ gErr=""; gUploadSize=0; str=''; gCurOFile=oFile; gCurImageSrc=oFile.value; inputname=oFile.name; i=inputname.substr((inputname.length-1),1); gCurInputIndex=i; if (gCurImageSrc.length>0){ //check for none jpg imgExt=new Image(); imgExt.onload=handleGoodImage; imgExt.onerror=handleBadImage; var fileName = gCurImageSrc.replace("//", "/"); // NN7 var imgURL = 'file:///' + fileName; if((navigator.appVersion.indexOf('Mac')>-1) && (navigator.appVersion.indexOf('MSIE')>-1)){ imgURL='file://' + fileName; } imgExt.src=imgURL; //finish check } } function ShowImgOfServer(NewPath,ImgD){ ImgD.src=NewPath; } ///////////////////////////////////// function DrawImage(ImgD,Index){ var flag=false; var image=new Image(); image.src=ImgD.src; ImgD.value=ImgD.src; if(image.fileSize>2048000){ image.outerHTML=""; gErr+="此图片尺寸过大,图片尺寸应小于2MB/n"; eval("form1.file"+Index+".outerHTML=/"<input type=///"file///" name=///"file"+Index+"///" style=///"width:275///" value=///"///" onChange=///"FileChange(this);///">/""); eval("form1.file"+Index+".fireEvent(/"onChange/")"); alert("此图片尺寸过大,图片尺寸应小于2MB/n"); return ; } if(image.src.substr(image.src.length-3,3).toLowerCase()!="jpg"){ image.outerHTML=""; gErr+="此图片类型不匹配,只能上传JPG(JPEG)格式文件/n"; eval("form1.file"+Index+".outerHTML=/"<input type=///"file///" name=///"file"+Index+"///" style=///"width:275///" value=///"///" onChange=///"FileChange(this);///">/""); eval("form1.file"+Index+".fireEvent(/"onChange/")"); alert("此图片类型不匹配,只能上传JPG(JPEG)格式文件/n"); return ; } tempFileName=image.src; var iLastDot; iLastLine=tempFileName.lastIndexOf('/'); if(iLastLine!=-1){ tempFileName=tempFileName.substring(iLastLine+1,tempFileName.length); } if(!CheckIfEnglish(tempFileName)){ image.outerHTML=""; gErr+="此图片文件名包含中文或其他不合法字符/n文件名只能由'a-z'、'A-Z'、'_'、'-'构成/n"; eval("form1.file"+Index+".outerHTML=/"<input type=///"file///" name=///"file"+Index+"///" style=///"width:275///" value=///"///" onChange=///"FileChange(this);///">/""); eval("form1.file"+Index+".fireEvent(/"onChange/")"); alert("此图片文件名包含中文或其他不合法字符/n文件名只能由'a-z'、'A-Z'、'_'、'-'构成/n"); return ; } if(gErr.length>0){ return; } if(image.width>0 && image.height>0){ flag=true; if(image.width/image.height>= 120/80){ if(image.width>120){ ImgD.width=120; ImgD.height=(image.height*120)/image.width; }else{ ImgD.width=image.width; ImgD.height=image.height; } ImgD.alt="图片大小(宽*高): "+image.width+"×"+image.height+"/n图片大小: "+image.fileSize+"/n图片路径: "+image.src; eval('document.all.width'+Index+'.value='+image.width); eval('document.all.height'+Index+'.value='+image.height); var oCreated=new Date(image.fileModifiedDate); eval('document.all.PicUpdateDate'+Index+'.value="'+oCreated.toLocaleString()+'"'); } else{ if(image.height>80){ ImgD.height=80; ImgD.width=(image.width*80)/image.height; }else{ ImgD.width=image.width; ImgD.height=image.height; } ImgD.alt="图片大小(宽*高): "+image.width+"×"+image.height+"/n图片大小: "+image.fileSize+"/n图片路径: "+image.src; eval('document.all.width'+Index+'.value='+image.width); eval('document.all.height'+Index+'.value='+image.height); var oCreated=new Date(image.fileModifiedDate); eval('document.all.PicUpdateDate'+Index+'.value="'+oCreated.toLocaleString()+'"'); } } if(parseInt(Index)==parseInt(form1.upcount.value)){ form1.upcount.value=parseInt(form1.upcount.value)+1; str+='<table width="100%" ><tr valign="middle" ><td align="center" id="tdimg" height="" width="120" ></td><td id="tdfile" >文件'+(parseInt(Index)+1)+':<input onpropertychange="FileChange(this);" type="file" name="file'+(parseInt(Index)+1)+'" style="width:275" ><input id="width'+(parseInt(Index)+1)+'" name="width'+(parseInt(Index)+1)+'" type="hidden" value=""><input id="height'+(parseInt(Index)+1)+'" name="height'+(parseInt(Index)+1)+'" type="hidden" value=""><input name="PicUpdateDate'+(parseInt(Index)+1)+'" type="hidden" id="PicUpdateDate'+(parseInt(Index)+1)+'"></td></tr></table>'; window.upid.insertAdjacentHTML("beforeEnd",str+'<br>'); } gUploadSize+=parseFloat(image.fileSize); } ////////////////////////////////////////// function AlbumChange(Value){ if(Value=='0'){ document.all.sNewAlbum.style.display='inline'; document.all.NewAlbum.focus(); } else{ document.all.sNewAlbum.style.display='none'; } return ; } function CheckIfEnglish( String ) { var Letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890-_."; var i; var c; if(String.charAt( 0 )=='-') return false; if( String.charAt( String.length - 1 ) == '-' ) return false; for( i = 0; i < String.length; i ++ ) { c = String.charAt( i ); if (Letters.indexOf( c ) < 0) return false; } return true; } </SCRIPT> </head> <body > <form name="form1" method="post" action=""> <TABLE align=center bgColor=#cccccc border=0 borderColorDark=#cccccc borderColorLight=#000000 cellPadding=5 cellSpacing=1 height=367 width="500"> <TBODY> <TR vAlign=center> <TD align=left bgColor=#ffffff colSpan=2 height=269 id=upid vAlign=top> <TABLE cellPadding=3 cellSpacing=1 width="100%"> <TBODY> <TR vAlign=center> <TD align=middle bgColor=#ffffff id=tdimg width=120></TD> <TD bgColor=#ffffff id=tdfile>文件1: <INPUT name=file1 onpropertychange=FileChange(this); style="WIDTH: 275px" type=file> <INPUT id=width1 name=width1 type=hidden> <INPUT id=height1 name=height1 type=hidden> <INPUT id=PicUpdateDate1 name=PicUpdateDate1 type=hidden></TD> </TR> </TBODY> </TABLE></TD> </TR> <TR bgColor=#eeeeee vAlign=center> <TD align=middle bgColor=#ebebeb colSpan=2 height=24> <DIV align=left>将图片上传至已有相册 <SELECT id=OldAlbum name=OldAlbum onchange=AlbumChange(this.value);> <OPTION value=0><新建相册></OPTION> <OPTION selected value=365>临时相册</OPTION> </SELECT> <INPUT id=TempAlbum name=TempAlbum type=hidden value=365> <SPAN id=sNewAlbum style="DISPLAY: none">或新建相册 <INPUT id=NewAlbum maxLength=50 name=NewAlbum onfocus=""> </SPAN></DIV></TD> </TR> <TR bgColor=#eeeeee vAlign=center> <TD align=middle bgColor=#ebebeb colSpan=2 height=24> <DIV align=center><FONT size=2> <INPUT class=bt name=Submit onclick=validate(); type=button value="· 上传已选图片 ·"> <INPUT id=upcount name=upcount type=hidden value=1> <INPUT id=from name=from type=hidden> </FONT></DIV></TD> </TR> </TBODY> </TABLE> </form> </body> </html>  [Ctrl+A 全选,提示:你可修改代码后运行]

11,不同的ALT

<SCRIPT language=JavaScript1.2> <!-- tPopWait=50; tPopShow=50000; showPopStep=10; popOpacity=100; sPop=null; curShow=null; tFadeOut=null; tFadeIn=null; tFadeWaiting=null; document.write("<style type='text/css'id='defaultPopStyle'>"); document.write(".cPopText { background-color: #FFFFFF; border: 1px #000000 solid; font-size: 12px; padding-right: 4px; padding-left: 4px; height: 20px; padding-top: 2px; padding-bottom: 2px; filter: Alpha(Opacity=0)}"); document.write("</style>"); document.write("<div id='dypopLayer' style='position:absolute;z-index:1000;' class='cPopText'></div>"); function showPopupText(){ var o=event.srcElement; MouseX=event.x; MouseY=event.y; if(o.alt!=null && o.alt!=""){o.dypop=o.alt;o.alt=""}; if(o.dypop!=sPop) { sPop=o.dypop; clearTimeout(curShow); clearTimeout(tFadeOut); clearTimeout(tFadeIn); clearTimeout(tFadeWaiting); if(sPop==null || sPop=="") { dypopLayer.innerHTML=""; dypopLayer.style.filter="Alpha()"; dypopLayer.filters.Alpha.opacity=0; } else { if(o.dyclass!=null) popStyle=o.dyclass else popStyle="cPopText"; curShow=setTimeout("showIt()",tPopWait); } } } function showIt(){ dypopLayer.className=popStyle; dypopLayer.innerHTML=sPop; popWidth=dypopLayer.clientWidth; popHeight=dypopLayer.clientHeight; if(MouseX+12+popWidth>document.body.clientWidth) popLeftAdjust=-popWidth-24 else popLeftAdjust=0; if(MouseY+12+popHeight>document.body.clientHeight) popTopAdjust=-popHeight-24 else popTopAdjust=0; dypopLayer.style.left=MouseX+12+document.body.scrollLeft+popLeftAdjust; dypopLayer.style.top=MouseY+12+document.body.scrollTop+popTopAdjust; dypopLayer.style.filter="Alpha(Opacity=0)"; fadeOut(); } function fadeOut(){ if(dypopLayer.filters.Alpha.opacity<popOpacity) { dypopLayer.filters.Alpha.opacity+=showPopStep; tFadeOut=setTimeout("fadeOut()",1); } else { dypopLayer.filters.Alpha.opacity=popOpacity; tFadeWaiting=setTimeout("fadeIn()",tPopShow); } } function fadeIn(){ if(dypopLayer.filters.Alpha.opacity>0) { dypopLayer.filters.Alpha.opacity-=1; tFadeIn=setTimeout("fadeIn()",1); } } document.onmouseover=showPopupText; //--> </script> <img src="images/logo.gif" alt="小雨在线">  [Ctrl+A 全选,提示:你可修改代码后运行]