How to reduce the size of a PDF file without loss of quality

When working with PDF-files, sometimes there may be a situation where the file size is too large, and you need to reduce the size of the PDF. The situation is not so often, but it happens. So, what are the possible ways to solve the problem? Just note that most of these files are compressed very badly. In particular, you should not expect a positive result when there are a lot of pictures in the file. Then the only solution will be to find the file without them, since attempts to squeeze it will not lead to anything good.

Using Scan kromsator

Consider one of the most effective ways. To begin, we convert the file into a picture. Required in Tiff! To do this, you can apply Scan kromsator (choose "Import" in the "File" menu). In principle, for this (especially for large and heavy files) it is better to use a virtual printer. It will be possible to make a translation into a picture format of the entire text layer, and not just images. With the same tool you need to process the resulting image file in order to reduce the size of the PDF. In principle, you can use more sophisticated graphic editors for this, but this is already an amateur.

Next, all the resulting pictures are best translated into djv format, using DjVu Lizardtech Editor. It should be noted that the program provides three modes of conversion:

• aggressive. Used for standard images, but it passes with significant quality loss, so it will not be possible to reduce the PDF accurately;
• Photo mode - used for files where there are a lot of pictures. Passes almost without loss of quality (however, the file size in the end is still less than the size of the source file);
• For any black and white images, we recommend choosing the mode with the same name, which will also take place with loss of quality (it's almost invisible in a black and white format). So you can reduce the size of PDF   In the case of some official documents.
  

But often it happens that only some of the document is represented as pictures. All the rest is text. Here it is necessary to work by hands: for each group create separate files, and then drive them through the appropriate modes. Then manually compose a new document and number the pages. So the easiest way to reduce the size of PDF, without resorting to sophisticated tricks.

The methods are different, simple and not very ...

If you are not attracted to such complicated methods, then you can use Adobe Acrobat. With it, you can convert the file in automatic mode. Of course, the result can vary considerably: you can not get an ideal compression.

Another option that requires certain knowledge is the use of Photoshop. In this case, you can achieve the maximum degree of compression of the object with virtually no loss of quality.

Using Photoshop, you can reduce the size of PDF for the most optimal use on the Internet. The "Compression" area in the file compression dialog box has three different sections. Each of them contains parameters for image compression and interpolation. How to lower the resolution? If you plan to use the file on the network, then it is necessary. If you plan to print the file in the future, you should not change the resolution settings! Disable the menu item that suggests using downsampling.

Downsampling is characterized by the fact that it reduces the number of pixels in the image. To use it on the image, select the interpolation, then enter the resolution that you need. In addition, you will be able to choose such settings by which all images whose resolution will be higher than the value you entered will automatically shrink. But once again we note that compressing PDF without losing its quality is a rather complicated process, and it is not always expedient to use it.