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---
title: CanvasRenderingContext2D.imageSmoothingQuality
slug: Web/API/CanvasRenderingContext2D/imageSmoothingQuality
tags:
- API
- Canvas
- CanvasRenderingContext2D
- imageSmoothingQuality
- 图像平滑度
translation_of: Web/API/CanvasRenderingContext2D/imageSmoothingQuality
---
<div>{{APIRef}} {{SeeCompatTable}}</div>
<p><strong>CanvasRenderingContext2D.imageSmoothingQuality</strong> 是 Canvas 2D API， 用于设置图像平滑度的属性。</p>
<h2 id="语法">语法</h2>
<pre class="syntaxbox"><var><em>ctx</em>.</var>imageSmoothingQuality<var> = value
value</var> = ctx.imageSmoothingQuality</pre>
<h3 id="选项">选项</h3>
<dl>
<dt><code>value</code></dt>
<dd>"low","medium","high"</dd>
</dl>
<h2 id="示例">示例</h2>
<h3 id="使用_imageSmoothingQuality_属性">使用 imageSmoothingQuality 属性</h3>
<p>这是一段简单的代码片段，对缩放的图片使用 <code>imageSmoothingQuality </code>属性。</p>
<h4 id="HTML">HTML</h4>
<pre class="brush: html"><canvas id="canvas"></canvas>
</pre>
<h4 id="JavaScript">JavaScript</h4>
<pre class="brush: js; highlight[7-10]">var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var img = new Image();
img.src = 'https://mdn.mozillademos.org/files/222/Canvas_createpattern.png';
img.onload = function() {
ctx.mozImageSmoothingEnabled = false;
ctx.imageSmoothingQuality = "Medium";
ctx.webkitImageSmoothingEnabled = false;
ctx.msImageSmoothingEnabled = false;
ctx.imageSmoothingEnabled = false;
ctx.drawImage(img, 0, 0, 400, 200);
};</pre>
<p>编辑下面代码，在线查看 Canvas 的变化：</p>
<div class="hidden">
<h6 id="Playable_code">Playable code</h6>
<pre class="brush: html"><canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas>
<div class="playable-buttons">
<input id="edit" type="button" value="Edit" />
<input id="reset" type="button" value="Reset" />
</div>
<textarea id="code" class="playable-code" style="height:140px;">
var img = new Image();
img.src = 'https://mdn.mozillademos.org/files/222/Canvas_createpattern.png';
img.onload = function() {
ctx.mozImageSmoothingEnabled = false;
ctx.webkitImageSmoothingEnabled = false;
ctx.imageSmoothingQuality = "Medium";
ctx.msImageSmoothingEnabled = false;
ctx.imageSmoothingEnabled = false;
ctx.drawImage(img, 0, 0, 400, 200);
};</textarea>
</pre>
<pre class="brush: js">var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var textarea = document.getElementById("code");
var reset = document.getElementById("reset");
var edit = document.getElementById("edit");
var code = textarea.value;
function drawCanvas() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
eval(textarea.value);
}
reset.addEventListener("click", function() {
textarea.value = code;
drawCanvas();
});
edit.addEventListener("click", function() {
textarea.focus();
})
textarea.addEventListener("input", drawCanvas);
window.addEventListener("load", drawCanvas);
</pre>
</div>
<p>{{ EmbedLiveSample('Playable_code', 700, 400) }}</p>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">Specification</th>
<th scope="col">Status</th>
<th scope="col">Comment</th>
</tr>
<tr>
<td>{{SpecName('HTML WHATWG', "#imagesmoothingquality", "imageSmoothingQuality")}}</td>
<td>{{Spec2('HTML WHATWG')}}</td>
<td>Initial definition.</td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<p>{{CompatibilityTable}}</p>
<div id="compat-desktop">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Chrome</th>
<th>Firefox (Gecko)</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{CompatChrome(54.0)}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatOpera(41)}}</td>
<td>{{CompatUnknown}}</td>
</tr>
</tbody>
</table>
</div>
<div id="compat-mobile">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Android</th>
<th>Android Webview</th>
<th>Firefox Mobile (Gecko)</th>
<th>IE Mobile</th>
<th>Opera Mobile</th>
<th>Safari Mobile</th>
<th>Chrome for Android</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatChrome(54.0)}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatOperaMobile(41)}}</td>
<td>{{CompatUnknown}}</td>
<td>{{CompatChrome(54.0)}}</td>
</tr>
</tbody>
</table>
</div>
<h2 id="参见">参见</h2>
<ul>
<li>接口定义, {{domxref("CanvasRenderingContext2D")}}</li>
<li>{{cssxref("image-rendering")}}</li>
</ul>
|
