Simple Trick to Create Smaller PDF Files
The core idea behind compressing a PDF file is better portability, easier transmission and smaller occupying space. An additional bonus is that a PDF file is the best format to compress, optimize, and is universally viewable, unlike JPEG, TIFF and other image formats. Also, PDF files can be flawlessly text-searchable, in file retrieval processes. So, how do I save PDF in a smaller format? Simplest trick is to save the PDF file after making essential changes using "Save As" command. This is slower than "Save" command, but it creates the PDF file that will be relatively smaller than the ones created by using "Save" command.
General Modifications that Must Be Made
But how do I save PDF in a smaller format more efficiently? Compressing a PDF file involves reducing the text, image size present in the PDF file. To an extent, the user can make provisional changes that aid in reducing the file size like decreasing the font size, using smaller resolution pictures, substituting color pictures by black and white, and so on. These are helpful, but depend on a number of factors, and hence these don't completely answer the question: "how do I save a PDF in a smaller format?".
Compression Algorithms and Its Uses
For a more specialized, professional approach, there are many types of software available to compress PDF files. These use concepts that are fundamentally of two types: lossy and lossless. As the names indicate, lossy methods tend to be liberal on the selectivity of the information in the PDF files which are generally used for images and sound files. An example of this type is JPEG compression. JPEG compression is on the basis of our human eye perception which sees changes in brightness of a picture more promptly than the color change. However, JPEG compression reduces the file size with minimum loss of information. The lossless side has various methods such as Flate algorithm (Run Length compression algorithm), ZIP compression, RLE compression, LZW compression, CCITT compressions. Each one of these works in a specialized, proficient manner in specific kinds of text and image types. Therefore, the question of efficiency of a PDF compressed file depends on how well these compression techniques are used. This answers the frequently aroused question: "how do I save a PDF in a smaller format?".