marbin mysql_跨浏览器图像灰度(grayscale)解决方案
首先,你需要在一個svg里聲明濾鏡,該svg可以內嵌到html文件里,也可以單獨保存。
[html] view plaincopy
如果該文件保存成了單獨的文件gray.svg,我們可以在html文件里加以引用。
[css] view plaincopy
img{
filter:url('gray.svg#grayscale'); /*灰度濾鏡放在gray.svg文件的id叫做grayscale的濾鏡里*/
}
如果該文件內嵌入了html文件里,則是這樣引用
[css] view plaincopy
img{
filter:url('#grayscale'); /*svg濾鏡內嵌入了html文件*/
}
當然,我們也可以直接把svg文件打包嵌入到css里,如果你沒有代碼潔癖的話
[css] view plaincopy
img {
filter: url('url("data:image/svg+xml;utf8,
200.3333%200%200%200%200%200%201%200'/>
#grayscale");')}
上面的方式,我們可以兼容大部分的瀏覽器(除了IE10、IE11),兼容的grayscale代碼如下。
[css] view plaincopy
img{
-webkit-filter: grayscale(100%); ? ? ? ? ? ?/* CSS3 filter方式,webkit內核方式,firefox外的絕大部分的現代瀏覽器*/
-moz-filter: grayscale(100%); ? ? ? ? ? ?/* 目前沒有實現 */
-ms-filter: grayscale(100%);
-o-filter: grayscale(100%);
filter: grayscale(100%); ? ? ? ? ? ?/* CSS3 filter方式,標準寫法*/
filter: url(filters.svg#grayscale); /* Firefox 4+ */
filter: gray; ? ? ? ? ? ? ? ? ? ? ? /* IE 6-9 */
}
img:hover{
-webkit-filter: grayscale(0%);
-moz-filter: grayscale(0%);
-ms-filter: grayscale(0%);
-o-filter: grayscale(0%);
filter: grayscale(0%);
filter: none; /* Firefox 4+, IE 6-9 */
}
4.js實現
對于IE10、11,我們怎么辦呢?就得用js啦。
[javascript] view plaincopy
var imgObj = document.getElementById('imgToGray');
function gray(imgObj) {
var canvas = document.createElement('canvas');
var canvasContext = canvas.getContext('2d');
var imgW = imgObj.width;
var imgH = imgObj.height;
canvas.width = imgW;
canvas.height = imgH;
canvasContext.drawImage(imgObj, 0, 0);
var imgPixels = canvasContext.getImageData(0, 0, imgW, imgH);
for (var y = 0; y < imgPixels.height; y++) {
for (var x = 0; x < imgPixels.width; x++) {
var i = (y * 4) * imgPixels.width + x * 4;
var avg = (imgPixels.data[i] + imgPixels.data[i + 1] + imgPixels.data[i + 2]) / 3;
imgPixels.data[i] = avg;
imgPixels.data[i + 1] = avg;
imgPixels.data[i + 2] = avg;
}
}
canvasContext.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width, imgPixels.height);
return canvas.toDataURL();
}
imgObj.src = gray(imgObj);
該解決方案主要參考ajaxblender的《Convert Images to Grayscale》,大家可以繼續閱讀查閱詳情。
5.跨瀏覽器解決方案
該方案主要參考《Cross-Browser Grayscale image example using CSS3 + JS v2.0. With browser feature detection using Modernizr》實現,英語沒問題的童鞋可以移步觀賞。博主寫了兩篇關于使用js實現跨瀏覽器解決灰度圖像問題的博客,第一篇自行實現瀏覽器檢測,第二篇使用了Modernizr。
該解決方案使用了jQuery和Modernizr,所以需要引入,此處省略,不知道怎么引入的童鞋,請自覺撞南墻100次。
對于IE瀏覽器
[javascript] view plaincopy
// IE 10 only CSS properties
var ie10Styles = [
'msTouchAction',
'msWrapFlow'];
var ie11Styles = [
'msTextCombineHorizontal'];
/*
* Test all IE only CSS properties
*/
var d = document;
var b = d.body;
var s = b.style;
var brwoser = null;
var property;
// Tests IE10 properties
for (var i = 0; i < ie10Styles.length; i++) {
property = ie10Styles[i];
if (s[property] != undefined) {
brwoser = "ie10";
}
}
// Tests IE11 properties
for (var i = 0; i < ie11Styles.length; i++) {
property = ie11Styles[i];
if (s[property] != undefined) {
brwoser = "ie11";
}
}
//Grayscale images only on browsers IE10+ since they removed support for CSS grayscale filter
if(brwoser == "ie10" || brwoser == "ie11" ){
$('body').addClass('ie11'); // Fixes marbin issue on IE10 and IE11 after canvas function on images
$('.grayscale img').each(function(){
var el = $(this);
el.css({"position":"absolute"}).wrap("
").clone().addClass('img_grayscale ieImage').css({"position":"absolute","z-index":"5","opacity":"0"}).insertBefore(el).queue(function(){var el = $(this);
el.parent().css({"width":this.width,"height":this.height});
el.dequeue();
});
this.src = grayscaleIe(this.src);
});
// Quick animation on IE10+
$('.grayscale img').hover(
function () {
$(this).parent().find('img:first').stop().animate({opacity:1}, 200);
},
function () {
$('.img_grayscale').stop().animate({opacity:0}, 200);
}
);
// Custom grayscale function for IE10 and IE11
function grayscaleIe(src){
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
var imgObj = new Image();
imgObj.src = src;
canvas.width = imgObj.width;
canvas.height = imgObj.height;
ctx.drawImage(imgObj, 0, 0);
var imgPixels = ctx.getImageData(0, 0, canvas.width, canvas.height);
for(var y = 0; y < imgPixels.height; y++){
for(var x = 0; x < imgPixels.width; x++){
var i = (y * 4) * imgPixels.width + x * 4;
var avg = (imgPixels.data[i] + imgPixels.data[i + 1] + imgPixels.data[i + 2]) / 3;
imgPixels.data[i] = avg;
imgPixels.data[i + 1] = avg;
imgPixels.data[i + 2] = avg;
}
}
ctx.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width, imgPixels.height);
return canvas.toDataURL();
};
};
對于其他瀏覽器
[javascript] view plaincopy
// If the browser does not support CSS filters filters, we are applying grayscale.js function
// This part of Grayscale images applies on Opera, Firefox and Safari browsers
if (!Modernizr.cssfilters) {
var $images = $(".grayscale img"), imageCount = $images.length, counter = 0;
// One instead of on, because it need only fire once per image
$images.one("load",function(){
// increment counter every time an image finishes loading
counter++;
if (counter == imageCount) {
// do stuff when all have loaded
grayscale($('.grayscale img'));
$(".grayscale img").hover(
function () {
grayscale.reset($(this));
},
function () {
grayscale($(this));
}
);
}
}).each(function () {
if (this.complete) {
// manually trigger load event in
// event of a cache pull
$(this).trigger("load");
}
});
}
DEMO就不自己做了,大家看老外的DEMO的。That's all.
---------------------------------------------------------------
前端開發whqet,關注web前端開發技術,分享網頁相關資源。
---------------------------------------------------------------
總結
以上是生活随笔為你收集整理的marbin mysql_跨浏览器图像灰度(grayscale)解决方案的全部內容,希望文章能夠幫你解決所遇到的問題。
- 上一篇: 三个9和4个9黄金区别
- 下一篇: 什么是商业银行