What is PDF Compression?
PDF compression software are specifically designed to reduce the size of PDFs. PDF compression programs utilize one of two techniques in order to compress a PDF. The first of those methods is called lossy, while the second is referred to as the lossless method. Lossy PDF compression does result in a certain amount of lost fidelity. However, it also offers the greatest compression levels. On the other hand, lossless compression does not result in loss of quality. Nonetheless, lossless compression cannot achieve the same results as lossy compression in terms of shrinking a PDF file. Compression is usually performed in order to save transmission time or storage space, since PDFs tend to have a large file size. When it comes to data transmission, compression can be done on just the data content itself or on the whole transmission unit - this can vary on a number of related factors.

Ways to Compress PDF
Compressing content may be as simple as getting rid of all the extraneous characters, putting in a single repeat character in order to decipher a string of repeated characters. Or it could mean, replacing small bit strings for characters that occur frequently. By utilizing this kind of compression, you can decrease a file up to half its size. PDF compression software utilize a formula or algorithm so that data is either compressed or decompressed. The algorithm involved is a crucial element in determining the quality of compression.
Compressing Images in PDF
When it comes to a PDF file, compression most likely refers to image compression. This is because PDF formats are typically designed to compress data as much as possible. PDF is also known as a page description language. Unlike PostScript, however, PDF is simplified with restricted functionality so that it is more lightweight. This results in better data structure and efficient compression algorithms as well. While looking at specific algorithms, each compression method is suited for a specific color image. For instance, in JPEG compression, grayscale and image images may be compresses by as much as ten times. Fairly good compression of single-color images is dependant on the compression filter and the image properties. Regardless of these factors, compressions of 12.5% to 50% may be expected.