如何调整大图像的大小，例如大于1000x1000像素？
jQuery.fn.fancyZoom = function(options){
var options = options || {};
var directory = options && options.directory ? options.directory : 'images';
var zooming = false;
if ($('#zoom').length == 0) {
var ext = $.browser.msie ? 'gif' : 'png';
var html = '<div id="zoom" style="display:none;"> \
<table id="zoom_table" style="border-collapse:collapse; width:100%; height:100%;"> \
<tbody> \
<tr> \
<td class="tl" style="background:url(' + directory + '/tl.' + ext + ') 0 0 no-repeat; width:20px; height:20px; overflow:hidden;" /> \
<td class="tm" style="background:url(' + directory + '/tm.' + ext + ') 0 0 repeat-x; height:20px; overflow:hidden;" /> \
<td class="tr" style="background:url(' + directory + '/tr.' + ext + ') 100% 0 no-repeat; width:20px; height:20px; overflow:hidden;" /> \
</tr> \
<tr> \
<td class="ml" style="background:url(' + directory + '/ml.' + ext + ') 0 0 repeat-y; width:20px; overflow:hidden;" /> \
<td class="mm" style="vertical-align:top; padding:10px;"> \
<div id="zoom_content"> \
</div> \
</td> \
<td class="mr" style="background:url(' + directory + '/mr.' + ext + ') 100% 0 repeat-y; width:20px; overflow:hidden;" /> \
</tr> \
<tr> \
<td class="bl" style="background:url(' + directory + '/bl.' + ext + ') 0 100% no-repeat; width:20px; height:20px; overflow:hidden;" /> \
<td class="bm" style="background:url(' + directory + '/bm.' + ext + ') 0 100% repeat-x; height:20px; overflow:hidden;" /> \
<td class="br" style="background:url(' + directory + '/br.' + ext + ') 100% 100% no-repeat; width:20px; height:20px; overflow:hidden;" /> \
</tr> \
</tbody> \
</table> \
<a href="#" title="Close" id="zoom_close" style="position:absolute; top:0; right:0;"> \
<img src="' + closebutton + '" alt="Close" style="border:none; margin:0; padding:0;" /> \
</a> \
</div>';
$('body').append(html);
$('html').click(function(e){if($(e.target).parents('#zoom:visible').length == 0) hide();});
$(document).keyup(function(event){
if (event.keyCode == 27 && $('#zoom:visible').length > 0) hide();
});
$('#zoom_close').click(hide);
}
var zoom = $('#zoom');
var zoom_table = $('#zoom_table');
var zoom_close = $('#zoom_close');
var zoom_content = $('#zoom_content');
var middle_row = $('td.ml,td.mm,td.mr');
this.each(function(i) {
$($(this).attr('href')).hide();
$(this).click(show);
});
return this;
function show(e) {
if (zooming) return false;
zooming = true;
var content_div = $($(this).attr('href'));
var zoom_width = options.width;
var zoom_height = options.height;
var width = window.innerWidth || (window.document.documentElement.clientWidth || window.document.body.clientWidth);
var height = window.innerHeight || (window.document.documentElement.clientHeight || window.document.body.clientHeight);
var x = window.pageXOffset || (window.document.documentElement.scrollLeft || window.document.body.scrollLeft);
var y = window.pageYOffset || (window.document.documentElement.scrollTop || window.document.body.scrollTop);
var window_size = {'width':width, 'height':height, 'x':x, 'y':y}
var width = (zoom_width || content_div.width()) + 60;
var height = (zoom_height || content_div.height()) + 60;
var d = window_size;
// ensure that newTop is at least 0 so it doesn't hide close button
var newTop = Math.max((d.height/2) - (height/2) + y, 0);
var newLeft = (d.width/2) - (width/2);
var curTop = e.pageY;
var curLeft = e.pageX;
zoom_close.attr('curTop', curTop);
zoom_close.attr('curLeft', curLeft);
zoom_close.attr('scaleImg', options.scaleImg ? 'true' : 'false');
$('#zoom').hide().css({
position : 'absolute',
top : curTop + 'px',
left : curLeft + 'px',
width : '1px',
height : '1px'
});
fixBackgroundsForIE();
zoom_close.hide();
if (options.closeOnClick) {
$('#zoom').click(hide);
}
if (options.scaleImg) {
zoom_content.html(content_div.html());
$('#zoom_content img').css('width', '100%');
} else {
zoom_content.html('');
}
$('#zoom').animate({
top : newTop + 'px',
left : newLeft + 'px',
opacity : "show",
width : width,
height : height
}, 500, null, function() {
if (options.scaleImg != true) {
zoom_content.html(content_div.html());
}
unfixBackgroundsForIE();
zoom_close.show();
zooming = false;
})
return false;
}
function hide() {
if (zooming) return false;
zooming = true;
$('#zoom').unbind('click');
fixBackgroundsForIE();
if (zoom_close.attr('scaleImg') != 'true') {
zoom_content.html('');
}
zoom_close.hide();
$('#zoom').animate({
top : zoom_close.attr('curTop') + 'px',
left : zoom_close.attr('curLeft') + 'px',
opacity : "hide",
width : '1px',
height : '1px'
}, 500, null, function() {
if (zoom_close.attr('scaleImg') == 'true') {
zoom_content.html('');
}
unfixBackgroundsForIE();
zooming = false;
});
return false;
}
function switchBackgroundImagesTo(to) {
$('#zoom_table td').each(function(i) {
var bg = $(this).css('background-image').replace(/\.(png|gif|none)\"\)$/, '.' + to + '")');
$(this).css('background-image', bg);
});
var close_img = zoom_close.children('img');
var new_img = close_img.attr('src').replace(/\.(png|gif|none)$/, '.' + to);
close_img.attr('src', new_img);
}
function fixBackgroundsForIE() {
if ($.browser.msie && parseFloat($.browser.version) >= 7) {
switchBackgroundImagesTo('gif');
}
}
function unfixBackgroundsForIE() {
if ($.browser.msie && $.browser.version >= 7) {
switchBackgroundImagesTo('png');
}
}
}
答案 0 :(得分：1)
您可能希望在服务器上进行图像大小调整，而不是在JavaScript中执行此操作，因为图像越大，您必须发送的字节越多，因此页面加载速度就越慢。如果您使服务器接受图像宽度和高度的cgi参数并让服务器执行调整大小，那么您可以减少I / O量，并且还可以使用可以执行此操作的语言来实现调整大小更快（例如，使用C或C ++与OpenCV库）。
这意味着如果只是对图像执行适当的XHR请求，那么您的JavaScript就会包含在内。如果图像足够小，可以在JavaScript中放大，那么您可以使用已经获取的图像在JavaScript中进行后续缩放。