如果您使用PDF 文件(PDF file)，您就会知道如果它们包含图形和图像，它们会如何很快变得非常大。幸运的是，您可以像压缩任何其他类型的文件一样压缩PDF 文件(PDF file)，这意味着可以大大节省PDF 文件(PDF file)的大小。
在这篇文章中，我将尝试向您展示一些减小PDF 文件(PDF file)大小的方法。如果您有 Adob e Acrobat(Acrobat)（不是免费的），您可以尝试方法 4 和 5，它们的效果非常好。还有一种方法可以在Mac OS X上专门减小(Mac OS X)PDF 文件(PDF file)的大小，即Method 3。
方法 1 – SmallPDF.com
缩小PDF 文件(PDF file)的最简单方法是使用名为SmallPDF.com的免费(SmallPDF.com)在线工具(online tool)。该网站非常干净（没有充满垃圾广告等），并且在减小大型PDF(PDF)文件的大小方面做得很好。
好在你可以在任何地方或任何操作系统(operating system)上使用它，它甚至支持HTML 5的新(HTML 5)拖放功能(drag and drop feature)，非常方便。它能够获取一个 500 KB 的文件(KB file)并将其缩小到大约 368 KB。不过，在Mac(Mac)上（方法 2(Method 2) ）还不错，我能够将相同的PDF缩小到只有 82 KB。
我用来压缩PDF文件的另一个在线工具是Neevia Compress PDF。它有很多选项和一些预设，如高压缩、低图像质量(image quality)或低压缩、高图像质量(image quality)等。
此外，您可以移除书签、移除PDF图层、移除注释、移除页面标签以及手动调整彩色和单色(color and monochrome) 图像压缩(image compression)的质量。
方法 2 – PDF 压缩器
PDF Compressor是一个免费程序，您可以为Windows XP/Vista/7/8下载，它可以让您快速有效地减小一个或多个PDF文件的大小。
它支持无损压缩，因此您不会看到PDF的质量有任何降低。它还支持加密的PDF文档，可以同时处理成百上千个PDF文件。
方法 3 – OS X PDF 过滤器
如果您有Mac ，则有一种非常简单的方法可以使用内置的Preview 应用程序(Preview app)显着减小PDF 文件(PDF file)的大小。首先，只需在Finder中双击PDF 文件，即可在Preview中打开您的(Preview)PDF 文件(PDF file)。默认情况下，除非您安装了Adobe Reader或第三方PDF 查看器，否则(PDF viewer)PDF 文件(PDF file)将在Preview中打开。在这种情况下，只需右键单击并选择Open With。
现在，单击文件(File)，然后单击导出(Export)。
您将看到一个弹出对话框，底部的选项之一是Quartz Filter。单击(Click)下拉菜单并选择减小文件大小(Reduce File Size)。
单击保存(Save)，您就完成了。使用此过滤器，我能够将PDF 文件(PDF file)从 500 KB 缩小到 82 KB。如果要对其进行微调，可以打开 ColorSync Utility。只需按(Just press) Command + Spacebar并开始输入 colorsync。然后，单击过滤器(Filters)并单击减小文件大小(Reduce File Size)。请注意，仅当您的PDF 文件(PDF file)中有大量高分辨率图像时，此处调整设置才有用。
在这里，您可以从Image Sampling(Image Sampling)中删除所有值并为Resolution输入一个值。如果您只需要在计算机上查看 PDF，如果图像很大，72 像素/英寸将大大减小PDF的大小。(PDF)您还可以尝试使用图像压缩(Image Compression)，看看您会得到什么类型的好处。
方法 4 – 打印到 Adobe PDF
尝试缩小PDF 文件(PDF file)的最简单方法是执行一个小技巧，基本上就是将PDF 文档(PDF document)打印到PDF 文件(PDF file)中。听起来很奇怪？它是。基本上，您在Adobe Reader中打开PDF 文件(PDF file)并将其打印到Adobe PDF 打印机(Adobe PDF printer)。
很多时候这工作得很好，并且会显着减小PDF 文件(PDF file)的大小。当您转到File – Print时，从打印机下拉列表中选择Adobe PDF ：
令人惊讶的是，仅通过使用这种方法，我就能够将 20 MB 的 PDF(MB PDF)文件缩小到 3 MB。不太确定它会做什么来缩小它，但它确实有效，特别是如果你有大量图像占用了大量空间。
方法 5 (Method 5) – Adobe Acrobat PDF Optimizer
从Adobe Acrobat的第 7 版开始，(version 7)高级(Advanced)菜单中有一个名为PDF Optimizer的新选项。
现在，您将被带到一个有一大堆选项可供配置的屏幕！
单击右上角的“审核空间使用情况(Audit space usage)”按钮，详细列出PDF 文件(PDF file)的每个组件以及它使用了多少空间：
如您所见，您可以执行六种不同的操作来缩小PDF 文件(PDF file)，包括优化或缩小图像、重新配置扫描的页面、调整字体、调整透明度、丢弃对象和清理PDF 文件(PDF file)。
例如，在图像下，您可以对图像进行下采样和压缩以节省空间。(Images)这非常有用，尤其是当您的图像具有非常高的分辨率时。如果不需要打印PDF 文件，您可以降低(PDF file)质量和(quality and number)每英寸像素数。要在屏幕上查看，您只需要 72 像素。
如果您将一堆页面扫描到PDF中，请单击“扫描页面”(Scanned Pages) 选项并使用(option and mess)从小尺寸(Small Size)到高质量(High Quality)的滑动条。根据需要进行调整。
Discard Objects和Discard User Data是PDF 文件(PDF file)的两个非常有用的清理选项。您基本上可以摆脱通常存储在每个PDF 文件(PDF file)中的所有额外垃圾。您可以删除标签、展平表单字段等。
对于Discard User Data，您可以摆脱评论、文档信息(document information)、元数据、对象数据、文件附件、来自其他应用程序的数据等。
最后，“清理”(Clean Up)选项卡会执行更多的内务处理任务，例如压缩整个文件和优化PDF以实现快速 Web 视图。
最好的办法是使用所有设置来查看最适合您的特定PDF 文件(PDF file)的设置。希望(Hopefully)上述五种方法中的一种可以将您的PDF 文件(PDF file)缩小到可以附加到电子邮件或发布(email or post)到网站的大小。如果您使用上述未提及的其他方法来缩小PDF 文件(PDF file)，请在评论中告知我们。享受！
How to Shrink PDF File Size
If you work with PDF files, you know how they can become very large very qυickly if they contain graphics and images. Luckily, you can compress PDF files lіke you can compreѕs any other type of file, which can mean big savings in the size of your PDF file.
In this post, I will try to show you a couple of methods to reduce the size of a PDF file. If you have Adobe Acrobat (which is not free), you can try out methods 4 and 5, which work really well. There is also a way to reduce PDF file size on Mac OS X specifically, which is Method 3.
Method 1 – SmallPDF.com
The simplest way to shrink your PDF file is to use a free online tool called SmallPDF.com. The site is super clean (not filled with spammy ads, etc) and it does a pretty good job of reducing the size of large PDF files.
What’s nice is that you can use it anywhere or any operating system and it even supports the new drag and drop feature of HTML 5, which is a nice convenience. It was able to take a 500 KB file and shrink it down to about 368 KB. Not too bad, however, on the Mac (Method 2), I was able to get that same PDF down to only 82 KB.
Another online tool I use to compress PDF files is Neevia Compress PDF. It has a bunch of options and some presets like high compression, low image quality or low compression, high image quality, etc.
In addition, you can remove bookmarks, remove PDF layers, remove annotations, remove page labels and manually adjust the quality for color and monochrome image compression.
Method 2 – PDF Compressor
PDF Compressor is a free program you can download for Windows XP/Vista/7/8 that lets you quickly and effectively reduce the size of one or many PDF files.
It supports lossless compression, so you should not see any reduction in the quality of the PDF. It also supports encrypted PDF documents and can work on a batch of hundreds or even thousands of PDF files at once.
Method 3 – OS X PDF Filter
If you have a Mac, there is a great and easy way to significantly reduce the size of a PDF file using the built in Preview app. Firstly, open your PDF file in Preview by just double-clicking on it in Finder. By default, PDF files will open in Preview unless you installed Adobe Reader or a third-party PDF viewer. In that case, just right-click and choose Open With.
Now, click on File and then click on Export.
You’ll get a pop-up dialog and one of the options at the bottom is Quartz Filter. Click on the drop down and select Reduce File Size.
Click Save and you’re done. I was able to get a PDF file from 500 KB down to only 82 KB using this filter. If you want to fine-tune it, you can open the ColorSync Utility. Just press Command + Spacebar and start typing colorsync. Then, click on Filters and click on Reduce File Size. Note that adjusting settings here is only useful if you have a lot of high resolution images in your PDF file.
Here you can remove all values from Image Sampling and enter a value for Resolution. If you only need the PDF to view on a computer, 72 pixels/inch will greatly reduce the size of your PDF if the images are large. You can also play around with the Image Compression and see what type of benefit you get.
Method 4– Print to Adobe PDF
The easiest way to try and shrink a PDF file is to perform a little trick, which basically is printing the PDF document to a PDF file. Sounds strange? It is. Basically, you open the PDF file in Adobe Reader and print it to the Adobe PDF printer.
A lot of time this works really well and will significantly reduce the size of your PDF file. When you go to File – Print, choose Adobe PDF from the drop down list of printers:
Amazingly enough, I’ve been able to shrink a 20 MB PDF file down to 3 MB just by using this method. Not really sure what it does to shrink it, but it works, especially if you have a good number of images that are eating up a lot of space.
Method 5 – Adobe Acrobat PDF Optimizer
Since version 7 of of Adobe Acrobat, there is a new option in the Advanced menu called PDF Optimizer.
Now you’ll be brought to a screen that has a whole bunch of options to configure!
Click on the Audit space usage button in the top right to get a detailed listed of each component of the PDF file and exactly how much space it is using:
As you can see, there are six different things you can do to make a PDF file smaller including optimizing or down-scaling images, reconfiguring scanned pages, adjusting fonts, adjusting transparency, discarding objects, and cleaning up the PDF file.
Under Images, for example, you can downsample and compress the images to save space. This is really useful, especially if your images are at a really high resolution. If the PDF file doesn’t need to be printed, you can reduce the quality and number of pixels per inch. For viewing on the screen, you only need 72 pixels.
If you scanned a bunch of pages into your PDF, then click on the Scanned Pages option and mess around with the sliding bar, which goes from Small Size to High Quality. Adjust as needed.
The Discard Objects and Discard User Data are two really useful cleanup options for PDF files. You can basically get rid of all the extra junk that is normally stored in every PDF file. You can remove tags, flatten form fields, etc.
For Discard User Data, you can get rid of comments, document information, metadata, object data, file attachments, data from other applications, and more.
Finally, the Clean Up tab does a few more housekeeping tasks like compressing the entire file and optimizing the PDF for fast web view.
The best thing to do is to play around with all the settings to see what works best for your particular PDF file. Hopefully, one of the five methods above will get your PDF file to a reduced size that you can attach to an email or post to a website. If you use a different method not mentioned above for shrinking your PDF files, let us know in the comments. Enjoy!
