🌗 位图反色（BMP 负片效果）Invert Bitmap Colours
把位图（BMP）或其他图片的颜色反转成负片：每个通道变成 255 减去原值，黑变白、红变青、蓝变黄。可以只反转红、绿、蓝中的某个通道，可选是否同时反转透明度（默认保持透明不变）。逐像素精确，反转两次即可还原。适合查看底片、制作暗色版图标、单色点阵屏的取反显示。默认导出 24 位 BMP，也可以导出 PNG，支持批量，图片只在浏览器本地处理。Invert the colours of a bitmap (BMP) or any other image into a negative: each channel becomes 255 minus its value, so black turns white, red turns cyan and blue turns yellow. You can invert just the red, green or blue channel, and choose whether transparency is inverted too (by default it is kept). The result is exact pixel for pixel, and inverting twice restores the original. Useful for viewing negatives, making dark-mode icons and inverted output for monochrome displays. The result is a 24-bit BMP by default, or PNG; works in bulk, and images are processed locally in your browser.
使用说明与常见问题How-to & FAQ
「位图反色（BMP 负片效果）」是什么？What is the Invert Bitmap Colours tool?
把位图（BMP）或其他图片的颜色反转成负片：每个通道变成 255 减去原值，黑变白、红变青、蓝变黄。可以只反转红、绿、蓝中的某个通道，可选是否同时反转透明度（默认保持透明不变）。逐像素精确，反转两次即可还原。适合查看底片、制作暗色版图标、单色点阵屏的取反显示。默认导出 24 位 BMP，也可以导出 PNG，支持批量，图片只在浏览器本地处理。Invert the colours of a bitmap (BMP) or any other image into a negative: each channel becomes 255 minus its value, so black turns white, red turns cyan and blue turns yellow. You can invert just the red, green or blue channel, and choose whether transparency is inverted too (by default it is kept). The result is exact pixel for pixel, and inverting twice restores the original. Useful for viewing negatives, making dark-mode icons and inverted output for monochrome displays. The result is a 24-bit BMP by default, or PNG; works in bulk, and images are processed locally in your browser.
如何使用「位图反色（BMP 负片效果）」？How do I use the Invert Bitmap Colours tool?
在「位图反色（BMP 负片效果）」中，选择或拖入文件，按需设置「反转通道」、「输出格式」等选项，然后点击每个结果旁的「下载」按钮即可；有多个文件时也可以点「全部下载（ZIP）」一次打包下载。In the Invert Bitmap Colours: Choose or drop your files, set "Channels", "Format", then click the Download button next to each result (with several files, "Download all (ZIP)" saves them together).
反色是怎么计算的？How is the inversion calculated?
每个选中的通道都用 255 减去原值：例如 (255, 0, 0) 红色变成 (0, 255, 255) 青色，(128, 128, 128) 中灰几乎不变。只反转一个通道时其他通道保持原样，可以做出特殊的配色效果。Each selected channel becomes 255 minus its value: red (255, 0, 0) becomes cyan (0, 255, 255), while mid-grey (128, 128, 128) barely changes. Inverting a single channel leaves the others untouched, which gives unusual colour effects.
透明的部分会怎样？What happens to transparent areas?
默认只反转颜色，透明度保持不变，所以 PNG 图标反色后形状不变；勾选“同时反转透明度”后，原来透明的地方变成不透明、不透明的地方变成透明。导出 BMP 时没有透明通道，透明部分会填成白色。By default only the colours are inverted and transparency is kept, so an icon keeps its shape. With Invert transparency too, transparent areas become opaque and opaque areas transparent. BMP has no transparency channel, so in a BMP transparent areas are filled with white.
导出的 BMP 是什么格式？What kind of BMP is produced?
默认导出 24 位不压缩 BMP（BITMAPINFOHEADER，自下而上存储），Windows 画图、Photoshop、GIMP、Python Pillow 和各种嵌入式工具都能直接打开。BMP 不支持透明，透明部分会填成白色并在结果里提示；需要保留透明请导出 PNG。By default a 24-bit uncompressed BMP (BITMAPINFOHEADER, stored bottom-up), which Windows Paint, Photoshop, GIMP, Python Pillow and embedded tools open directly. BMP has no transparency, so transparent areas are filled with white (the result says so); export PNG to keep transparency.
有哪些选项可以调整？What options can I adjust?
「位图反色（BMP 负片效果）」的设置：「反转通道」可选 红、绿、蓝全部、只反转红色、只反转绿色、只反转蓝色（默认 红、绿、蓝全部）；「输出格式」可选 BMP、PNG（默认 BMP）；可勾选：「同时反转透明度」；可选文件：常见图片格式（含 HEIC、HEIF、AVIF、WEBP、BMP、JFIF）。改动任一选项后结果会按新设置重新生成。Settings in the Invert Bitmap Colours — "Channels": All of R, G, B, Red only, Green only, Blue only (default All of R, G, B); "Format": BMP, PNG (default BMP); tick boxes: "Invert transparency too"; files: common image formats (including HEIC, HEIF, AVIF, WEBP, BMP, JFIF). Changing any option regenerates the result with the new setting.
图片会被上传到服务器吗？Are my images uploaded?
不会。「位图反色（BMP 负片效果）」使用浏览器 Canvas 在本地处理图片，处理后的文件直接从你的浏览器下载。No. The Invert Bitmap Colours processes images locally with the browser Canvas API and the result downloads straight from your browser.
「位图反色（BMP 负片效果）」免费吗？需要注册吗？Is the Invert Bitmap Colours free? Do I need an account?
「位图反色（BMP 负片效果）」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 Invert Bitmap Colours is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.