✒️ PNG 转 SVG（位图矢量化）PNG to SVG Converter (Vectorize)
把 PNG、JPG 等位图描摹成可无限放大的 SVG 矢量图：可调颜色数、细节程度、降噪，并提供纯黑白描摹模式，适合 Logo、图标和线稿；描摹在浏览器后台线程完成，图片不上传。Trace PNG, JPG and other bitmaps into scalable SVG vector paths — choose the number of colors, level of detail and noise smoothing, or use 1-bit black & white tracing for logos, icons and line art. Runs in a background thread in your browser; nothing is uploaded.
使用说明与常见问题How-to & FAQ
「PNG 转 SVG（位图矢量化）」是什么？What is the PNG to SVG Converter (Vectorize) tool?
把 PNG、JPG 等位图描摹成可无限放大的 SVG 矢量图：可调颜色数、细节程度、降噪，并提供纯黑白描摹模式，适合 Logo、图标和线稿；描摹在浏览器后台线程完成，图片不上传。Trace PNG, JPG and other bitmaps into scalable SVG vector paths — choose the number of colors, level of detail and noise smoothing, or use 1-bit black & white tracing for logos, icons and line art. Runs in a background thread in your browser; nothing is uploaded.
如何使用「PNG 转 SVG（位图矢量化）」？How do I use the PNG to SVG Converter (Vectorize) tool?
在「PNG 转 SVG（位图矢量化）」中，按需设置「颜色数」、「细节」、「降噪模糊」、「描摹尺寸」等选项，然后点击「下载 SVG」、「复制 SVG 代码」按钮即可。支持拖放文件。In the PNG to SVG Converter (Vectorize): Set "Colors", "Detail", "Smoothing blur", "Trace size", then click "Download SVG", "Copy SVG code". Drag-and-drop files is supported.
PNG 转 SVG 的原理是什么？How does PNG to SVG conversion work?
工具先把图片的颜色量化成指定数量的色块，再沿每个色块的边缘拟合直线和二次贝塞尔曲线，生成 SVG 路径（使用开源的 imagetracerjs，Unlicense 许可）。这是“描摹”，不是简单把位图嵌入 SVG。The image is quantised into the chosen number of color regions, then each region's outline is fitted with lines and quadratic Bézier curves to produce SVG paths (using the open-source imagetracerjs, Unlicense). It is genuine tracing, not just embedding the bitmap inside an SVG.
什么图片效果最好？Which images trace best?
颜色少、边缘清晰的 Logo、图标、插画、线稿和签名效果最好。照片会变成色块拼贴风格，细节越高文件越大，通常不如保留为 JPG/WebP。Logos, icons, flat illustrations, line art and signatures with few colors and sharp edges work best. Photos become a posterised mosaic; higher detail means much bigger files and they are usually better kept as JPG/WebP.
为什么要限制描摹尺寸？Why limit the trace size?
大图描摹耗时和 SVG 体积都会急剧增加。默认先缩小到最长边 1000 像素；SVG 本身可以无损放大，所以这通常不影响使用。超过 60 秒会自动停止。Tracing time and SVG size grow quickly with resolution, so by default the image is scaled to 1000 px on its longest side first; the SVG itself scales losslessly, so this rarely matters. Jobs over 60 seconds are stopped.
透明背景会保留吗？Is transparency kept?
彩色模式下透明区域会生成透明度为 0 的路径，显示效果保持透明；黑白描摹模式会把透明区域当作白色。In color mode transparent regions become zero-opacity paths, so they stay transparent when displayed; black & white mode treats transparency as white.
图片会上传吗？Is my image uploaded?
不会。描摹在浏览器的后台线程（Web Worker）里完成，图片和生成的 SVG 都不会离开你的设备。No. Tracing runs in a background Web Worker in your browser; neither the image nor the SVG leaves your device.
「PNG 转 SVG（位图矢量化）」免费吗？需要注册吗？Is the PNG to SVG Converter (Vectorize) free? Do I need an account?
「PNG 转 SVG（位图矢量化）」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The PNG to SVG Converter (Vectorize) is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.