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减小 PDF 文件大小

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减小 PDF 文件大小

我拍了一些照片并在 Omnigraffle（OSX）上制作了一个巨大的 PDF。

现在我需要通过电子邮件发送该 PDF，但由于每张照片都是 5MB，因此文件很大。不过，通过电子邮件发送时我不需要高分辨率照片。

那么什么程序可以获取我的 PDF，将所有图像调整为低分辨率并保存？

答案1

在预览中打开 PDF，选择文件»另存为...，然后选择石英过滤器命名减小文件大小。

在此处输入图片描述

使用ColorSync 实用程序微调滤镜。复制减小文件大小然后更改设置。

我建议您首先尝试清除图像采样阻止，除非解决，大约在 150-300 DPI 之间，具体取决于您想要节省多少。

在此处输入图片描述

答案2

灵感来自马克斯·格林尼斯特&米兰·库普切维奇感谢 Burgi 对示例脚本的解释：它使用电子书过滤器将 PDF 大小从巨大减小到小

brew install ghostscript # aptitude work too if you do not have brew

compresspdf() {
    echo 'Usage: compresspdf [input file] [output file] [screen|ebook|printer|prepress]'
    gs -sDEVICE=pdfwrite -dNOPAUSE -dQUIET -dBATCH -dPDFSETTINGS=/${3:-"screen"} -dCompatibilityLevel=1.4 -sOutputFile="$2" "$1"
}

compresspdf "Massive.pdf" "Small.pdf" ebook

Gs 选项：

-dPDFSETTINGS=/screen   (screen-view-only quality, 72 dpi images)
-dPDFSETTINGS=/ebook    (low quality, 150 dpi images)
-dPDFSETTINGS=/printer  (high quality, 300 dpi images)
-dPDFSETTINGS=/prepress (high quality, color preserving, 300 dpi imgs)
-dPDFSETTINGS=/default  (almost identical to /screen)

答案3

我不知道有哪个程序可以做你想做的事，但产生相同最终结果的另一种方法是先用图形程序压缩图像，然后然后将它们放入文档中并将其转换为 PDF。

答案4

谢谢@Mickaël，你的解决方案太棒了，

我对分割页面的控制做了些小改进 -> 默认操作，以及一些工具示例 - https://github.com/Elia-Sh/toolsAndUtils/blob/master/pdfSplit.sh

保存文件 -

#!/bin/bash

# inspired by: 
#   https://superuser.com/questions/293856/reducing-pdf-file-size
#   https://www.ghostscript.com/doc/current/Use.htm#File_output

usage() {
    cat<<EOF
Usage:
    ${0} <input file> <output file> [screen|ebook|printer|prepress]

EOF
}
# Examples:
# Note: Ghostscript must be installed on your system
# Note that <n> represents the number of pages in the original document;

#     * Only split file to pages; no range available -
#         \$ ${0} someFile.pdf
#       will create the following single page files:
#         someFile_page_0001.pdf, someFile_page_0002.pdf someFile_page_0003.pdf, someFile_page_000<n>.pdf

#     * Split page to custom output file name -
#         \$ ${0} someFile.pdf newFileName_pageNumer_%2d.pdf
#       will create the following single page files:
#         newFileName_pageNumer_01.pdf, newFileName_pageNumer_02.pdf, newFileName_pageNumer_03.pdf, newFileName_pageNumer_0<n>.pdf

#     * Only reduce quality of pdf file !without! splitting -
#         \$ ${0} someFile.pdf newFileName.pdf ebook
#       will create the following single file: newFileName.pdf with reduced quality

#     * Reduce quality !and! split pdf to single pages -
#         \$ ${0} someFile.pdf newFileName_%2d.pdf ebook
#       will create the following single page files, with lower qualuty
#         newFileName_page_01.pdf, newFileName_page_02.pdf, newFileName_page_03.pdf, newFileName_page_0<n>.pdf

### main ###
DEFAULT_QUALITY="printer"
numberOfArguments=$#

case $numberOfArguments in
    1)
        # only split the file
        fileNameInput=$1
        fileNameOutput="${fileNameInput}_page_%04d.pdf"
        pdfSettings=$DEFAULT_QUALITY
        ;;
    2)
        # user supplied input and output files
        fileNameInput=$1
        fileNameOutput=$2
        pdfSettings=$DEFAULT_QUALITY
        ;;
    3)
        # user supplied input and output files
        fileNameInput=$1
        fileNameOutput=$2
        pdfSettings=$3
        ;;
    *)
    # incorrect syntax print usage and exit
        echo "Error: Illegal number of parameters."
        usage
        exit 1
    ;;
  esac

if [[ ! -f $fileNameInput ]]; then
    echo "Error: ${fileNameInput} not found!"
    exit 2
fi

if ! which gs > /dev/null 2>&1; then
    echo "Error: Looks like the Ghostscript package is not installed on your system."
    exit 3
fi

cmdToExecute="gs -sDEVICE=pdfwrite -dNOPAUSE -dQUIET -dBATCH \
    -dPDFSETTINGS=/$pdfSettings -dCompatibilityLevel=1.4 \
    -sOutputFile=$fileNameOutput $fileNameInput"

echo -e "Executing:\n    "$cmdToExecute

$cmdToExecute
# finish script with the return code from gs command
exit $?

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