如何将 imagepalettecopy 与 imagecreate 函数结合使用？实用示例分享

gitbox 2025-08-21

<span><span><span class="hljs-meta">&lt;?php</span></span><span>
<span class="hljs-comment">/*
本示例文章将介绍如何将 imagepalettecopy 与 imagecreate 函数结合使用，
并通过实例代码展示其应用场景与技巧。
*/</span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>

----------------------------------------

</span><span><span class="hljs-comment"># 如何将 imagepalettecopy 与 imagecreate 函数结合使用？实用示例分享</span></span><span>


</span><span><span class="hljs-comment">## 一、`imagecreate` 与 `imagepalettecopy` 简介</span></span><span>

- **`</span><span><span class="hljs-title function_ invoke__">imagecreate</span></span><span>(</span><span><span class="hljs-keyword">int</span></span><span> </span><span><span class="hljs-variable">$width</span></span><span>, </span><span><span class="hljs-keyword">int</span></span><span> </span><span><span class="hljs-variable">$height</span></span><span>)`**  
  用于创建一个基于调色板的图像（索引颜色图像），适合对颜色数量有限的图片进行处理。  
  返回值是一个图像资源句柄。

- **`</span><span><span class="hljs-title function_ invoke__">imagepalettecopy</span></span><span>(resource </span><span><span class="hljs-variable">$dst</span></span><span>, resource </span><span><span class="hljs-variable">$src</span></span><span>)`**  

</span><span><span class="hljs-comment">## 二、应用场景</span></span><span>

</span><span><span class="hljs-number">1</span></span><span>. **批量生成相同风格的缩略图**  

</span><span><span class="hljs-number">2</span></span><span>. **索引图像的调色板同步**  
   如果多个索引图像需要在后续合并或比较颜色，调色板保持一致非常重要。

</span><span><span class="hljs-comment">## 三、代码示例</span></span><span>


```php
</span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 创建源图像（索引颜色）</span></span><span>
</span><span><span class="hljs-variable">$src</span></span><span> = </span><span><span class="hljs-title function_ invoke__">imagecreate</span></span><span>(</span><span><span class="hljs-number">200</span></span><span>, </span><span><span class="hljs-number">200</span></span><span>);
</span><span><span class="hljs-variable">$red</span></span><span>   = </span><span><span class="hljs-title function_ invoke__">imagecolorallocate</span></span><span>(</span><span><span class="hljs-variable">$src</span></span><span>, </span><span><span class="hljs-number">255</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>);
</span><span><span class="hljs-variable">$green</span></span><span> = </span><span><span class="hljs-title function_ invoke__">imagecolorallocate</span></span><span>(</span><span><span class="hljs-variable">$src</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">255</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>);
</span><span><span class="hljs-variable">$blue</span></span><span>  = </span><span><span class="hljs-title function_ invoke__">imagecolorallocate</span></span><span>(</span><span><span class="hljs-variable">$src</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">255</span></span><span>);

</span><span><span class="hljs-comment">// 用红色填充背景</span></span><span>
</span><span><span class="hljs-title function_ invoke__">imagefill</span></span><span>(</span><span><span class="hljs-variable">$src</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-variable">$red</span></span><span>);

</span><span><span class="hljs-comment">// 创建目标图像（索引颜色）</span></span><span>
</span><span><span class="hljs-variable">$dst</span></span><span> = </span><span><span class="hljs-title function_ invoke__">imagecreate</span></span><span>(</span><span><span class="hljs-number">200</span></span><span>, </span><span><span class="hljs-number">200</span></span><span>);

</span><span><span class="hljs-title function_ invoke__">imagepalettecopy</span></span><span>(</span><span><span class="hljs-variable">$dst</span></span><span>, </span><span><span class="hljs-variable">$src</span></span><span>);

</span><span><span class="hljs-title function_ invoke__">imagefill</span></span><span>(</span><span><span class="hljs-variable">$dst</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>, </span><span><span class="hljs-variable">$blue</span></span><span>);

</span><span><span class="hljs-comment">// 输出图片进行对比</span></span><span>
</span><span><span class="hljs-title function_ invoke__">header</span></span><span>(</span><span><span class="hljs-string">"Content-Type: image/png"</span></span><span>);

</span><span><span class="hljs-comment">// 这里只输出目标图像，你可以根据需要保存两个图像进行查看</span></span><span>
</span><span><span class="hljs-title function_ invoke__">imagepng</span></span><span>(</span><span><span class="hljs-variable">$dst</span></span><span>);

</span><span><span class="hljs-comment">// 释放资源</span></span><span>
</span><span><span class="hljs-title function_ invoke__">imagedestroy</span></span><span>(</span><span><span class="hljs-variable">$src</span></span><span>);
</span><span><span class="hljs-title function_ invoke__">imagedestroy</span></span><span>(</span><span><span class="hljs-variable">$dst</span></span><span>);
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

四、总结

通过 imagecreate 与 imagepalettecopy 的结合，我们可以方便地在多个索引图像间共享相同的调色板，避免了手动分配相同颜色的重复工作。在批量处理、调色板同步、保持视觉统一等场景中，这种方法都非常实用。掌握这些函数的用法，将有助于我们在 PHP 图像处理项目中更高效地管理颜色数据。

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