🌓 黑白图片制作Create Black and White Image

使用说明与常见问题How-to & FAQ

「黑白图片制作」是什么？What is the Create Black and White Image tool?

把彩色照片变成黑白：支持灰度、固定阈值、Otsu 自动阈值，以及 Floyd–Steinberg、Atkinson、Bayer 抖动等纯黑白效果，可反相，实时预览后下载 PNG/JPG，图片不上传。Turn any photo into black and white — true grayscale, fixed or automatic (Otsu) threshold, or pure black-and-white dithering with Floyd–Steinberg, Atkinson or Bayer patterns, plus invert. Live preview, PNG/JPG download, nothing uploaded.

如何使用「黑白图片制作」？How do I use the Create Black and White Image tool?

在「黑白图片制作」中，按需设置「效果」、「阈值」、「格式」等选项，然后点击「下载」按钮即可。支持拖放文件。In the Create Black and White Image: Set "Effect", "Threshold", "Format", then click "Download". Drag-and-drop files is supported.

灰度和黑白有什么区别？What is the difference between grayscale and black & white?

灰度保留 256 级灰色，看起来像黑白照片；阈值和抖动模式输出只有纯黑和纯白两种颜色（PNG 直接保存为真正的 1 位黑白 PNG，像素值严格为 0 或 255；JPG 是有损压缩，黑白交界处会出现少量接近黑/白的灰点，需要严格黑白请选 PNG），适合打印、激光雕刻、印章、热敏打印机等只能表现黑白的场景。Grayscale keeps 256 shades of grey, like a black-and-white photo. Threshold and dither modes output only pure black and pure white (PNG is saved as a true 1-bit PNG with pixel values strictly 0 or 255; JPG is lossy, so a few near-black/near-white grey pixels appear along edges — choose PNG when you need strict black and white), which suits printing, laser engraving, stamps and thermal printers that can only show two tones.

灰度是怎么计算的？How is grayscale computed?

按 BT.709 亮度公式 0.2126R + 0.7152G + 0.0722B 计算，透明部分视为白色背景。Using BT.709 luminance 0.2126R + 0.7152G + 0.0722B; transparent areas are treated as a white background.

Otsu 自动阈值是什么？What is the Otsu auto threshold?

Otsu 方法会分析图片的亮度直方图，自动找出最能把前景和背景分开的阈值，适合扫描文档、签名等明暗分明的图片；找到的阈值会显示在状态栏。Otsu's method analyses the brightness histogram and picks the threshold that best separates foreground from background — good for scanned documents and signatures. The chosen value is shown in the status line.

几种抖动有什么不同？How do the dithering modes differ?

Floyd–Steinberg 把误差扩散到相邻像素，细节最好；Atkinson（老式 Mac 风格）对比度更高、亮部更干净；Bayer 网点是规则的格子纹理，复古、适合像素风。Floyd–Steinberg diffuses error to neighbours for the most detail; Atkinson (classic Mac look) gives higher contrast and cleaner highlights; Bayer produces a regular grid pattern with a retro, pixel-art feel.

图片会上传吗？Is my image uploaded?

不会，所有处理都在浏览器本地完成；下载的图片不包含原图的 EXIF 信息。No, all processing happens locally in your browser, and the downloaded image contains no EXIF data from the original.

「黑白图片制作」免费吗？需要注册吗？Is the Create Black and White Image free? Do I need an account?

「黑白图片制作」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 Create Black and White Image is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.