🖼️ BMP 转 PDFBMP to PDF Converter
把 BMP 位图（Windows 画图、截图、扫描软件和工控设备导出的 .bmp）转换为 PDF：多张合并为一个文件并可调整顺序，默认无损保存，体积通常比 BMP 小很多，可选纸张大小和页边距，本地完成。Convert BMP bitmaps — from Paint, screenshots, scanners and industrial equipment — into a PDF. Combine and reorder several files; pixels are stored losslessly by default and the PDF is usually far smaller than the BMPs, with page size and margins. Done locally.
使用说明与常见问题How-to & FAQ
「BMP 转 PDF」是什么？What is the BMP to PDF Converter tool?
把 BMP 位图（Windows 画图、截图、扫描软件和工控设备导出的 .bmp）转换为 PDF：多张合并为一个文件并可调整顺序，默认无损保存，体积通常比 BMP 小很多，可选纸张大小和页边距，本地完成。Convert BMP bitmaps — from Paint, screenshots, scanners and industrial equipment — into a PDF. Combine and reorder several files; pixels are stored losslessly by default and the PDF is usually far smaller than the BMPs, with page size and margins. Done locally.
如何使用「BMP 转 PDF」？How do I use the BMP to PDF Converter tool?
在「BMP 转 PDF」中，按需设置「页面大小」、「方向」、「页边距 (0–50 mm)」、「图片压缩」、「JPEG 质量 (30–100)」等选项，然后点击「生成 PDF」、「清空」按钮即可。支持拖放文件。In the BMP to PDF Converter: Set "Page size", "Orientation", "Margin (0–50 mm)", "Image compression", "JPEG quality (30–100)", then click "Create PDF", "Clear". Drag-and-drop files is supported.
为什么 PDF 比 BMP 小那么多？Why is the PDF so much smaller than the BMP?
BMP 通常完全不压缩（每像素 3 字节），而 PDF 里用无损的 Flate 压缩（与 PNG 相同的算法）保存像素，画质完全一样，截图和图表这类大片纯色的图片通常能缩小很多，照片类图片缩小得少一些（具体比例取决于图片内容）。BMP is usually uncompressed (3 bytes per pixel), while the PDF stores the same pixels with lossless Flate compression (the algorithm PNG uses). Quality is identical, and screenshots or charts with large flat areas usually shrink a lot, photos less so (the exact saving depends on the image).
支持哪些 BMP？Which BMP variants work?
支持浏览器能解码的常见 BMP：1/4/8 位调色板、16/24/32 位，以及 RLE 压缩的 BMP。极少见的 OS/2 旧格式或损坏文件会提示无法读取；像素数据比文件头声明的少（文件被截断）时会提示文件不完整并跳过。Common BMPs the browser can decode: 1/4/8-bit palette, 16/24/32-bit and RLE-compressed files. Rare old OS/2 variants or damaged files show a cannot-read message, and a file with less pixel data than its header declares (truncated) is reported as incomplete and skipped.
页面大小和页边距怎么选？How do I choose page size and margins?
“按图片尺寸”让每页正好等于图片大小（按图片自带的 DPI 换算，没有 DPI 信息时按 96 DPI），没有白边；选 A4 / Letter 等标准纸张时，图片会等比例缩放并居中，方向选“自动”时横图自动用横向页面。"Image size" makes each page exactly the size of its image (using the image's own DPI, or 96 DPI if none is stored), with no white border. With A4, Letter and other paper sizes the image is scaled proportionally and centred; with orientation on Auto, landscape images get landscape pages.
图片会上传吗？Are my images uploaded?
不会。解码和生成 PDF 都在你的浏览器里完成（pdf-lib），图片不会离开你的设备。No. Decoding and PDF creation both happen in your browser (pdf-lib); your images never leave your device.
「BMP 转 PDF」免费吗？需要注册吗？Is the BMP to PDF Converter free? Do I need an account?
「BMP 转 PDF」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 BMP to PDF Converter is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.