👻 图片半透明（调整不透明度）Make Image Semitransparent

使用说明与常见问题How-to & FAQ

「图片半透明（调整不透明度）」是什么？What is the Make Image Semitransparent tool?

把图片变成半透明：设置 0–100% 的不透明度，或做从一侧到另一侧、从中心到边缘的透明渐变，原本透明的地方仍然透明。导出无损 PNG（颜色不受半透明影响）或 WebP，适合做水印、叠加图层、PPT 和网页背景，支持批量，图片只在浏览器本地处理。Make an image semi-transparent: set the opacity from 0 to 100%, or fade it from one side to the other or from the centre to the edges, while areas that were already transparent stay transparent. Exports a lossless PNG (colours are kept exactly, even at low opacity) or WebP — handy for watermarks, overlays, slides and web backgrounds. Works in bulk, locally in your browser.

如何使用「图片半透明（调整不透明度）」？How do I use the Make Image Semitransparent tool?

在「图片半透明（调整不透明度）」中，选择或拖入文件，按需设置「方式」、「不透明度」、「渐变方向」、「结束不透明度」、「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 Make Image Semitransparent: Choose or drop your files, set "Mode", "Opacity", "Fade direction", "End opacity", "Format", then click the Download button next to each result (with several files, "Download all (ZIP)" saves them together).

颜色会因为半透明而变化吗？Do colours change when the image becomes semi-transparent?

不会。浏览器画布导出 PNG 时会把半透明像素的颜色四舍五入，不透明度很低时颜色可能偏差好几个色阶；本工具导出 PNG 时自己编码，只改透明度、RGB 颜色保持原值（WebP 由浏览器编码）。原本就半透明的像素会在原有透明度上再乘以你设置的不透明度。No. A browser canvas rounds the colours of semi-transparent pixels when it exports a PNG, which can shift them by several levels at low opacity. This tool encodes the PNG itself, so only the alpha changes and the RGB values stay exactly as they were (WebP is encoded by the browser). Pixels that were already semi-transparent have their alpha multiplied by your opacity.

透明渐变怎么用？How does the fade work?

选择“透明渐变”后，从起始不透明度平滑过渡到结束不透明度，例如从左到右 100% → 0%，图片右边会逐渐淡出；“从中心到边缘”则中间清晰、四周逐渐透明，像柔和的晕影，适合做拼接、海报背景或幻灯片配图。Choose Fade to blend smoothly from the start opacity to the end opacity — for example left → right from 100% to 0% fades the right side out. Centre → edges keeps the middle solid and makes the edges fade away like a soft vignette, good for blending images, poster backgrounds or slides.

为什么不能导出 JPG？Why is there no JPG option?

JPG 格式没有透明通道，保存成 JPG 半透明效果就没了，所以只提供 PNG 和 WebP。如果需要“看起来变淡”的 JPG，可以先在这里生成半透明 PNG，再用“图片添加背景”工具铺上白色或其他颜色。JPG has no alpha channel, so the transparency would be lost — that's why only PNG and WebP are offered. If you need a JPG that just looks faded, make the semi-transparent PNG here, then put a white or coloured background behind it with Add Image Background.

有哪些选项可以调整？What options can I adjust?

「图片半透明（调整不透明度）」的设置：「方式」可选 整体半透明、透明渐变（默认 整体半透明）；「不透明度」默认 50，范围 0–100；「渐变方向」可选 从左到右、从右到左、从上到下、从下到上、从中心到边缘（默认 从左到右）；「结束不透明度」默认 0，范围 0–100；「输出格式」可选 PNG、WebP（默认 PNG）；「质量」默认 92，范围 40–100；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 Make Image Semitransparent — "Mode": Uniform, Fade (default Uniform); "Opacity" default 50, range 0–100; "Fade direction": Left → right, Right → left, Top → bottom, Bottom → top, Centre → edges (default Left → right); "End opacity" default 0, range 0–100; "Format": PNG, WebP (default PNG); "Quality" default 92, range 40–100; 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。「图片半透明（调整不透明度）」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 Make Image Semitransparent processes images locally with the browser Canvas API and the result downloads straight from your browser.

「图片半透明（调整不透明度）」免费吗？需要注册吗？Is the Make Image Semitransparent free? Do I need an account?

「图片半透明（调整不透明度）」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 Make Image Semitransparent is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.