Reducing the size of graphics files by bytes without reducing the quality of the image is called image compression. Due to the decrease in the size of the file, the memory space increases and that is why we can store more images in the same memory space or disk space in the system. This reduces the time it takes to send images over the Internet or download them from a web page.
Computer Science sometimes has some repetitive elements ie the same information is shown again and again. For example, in files that contain only text, many times the same words are repeated over and over again. There are many methods of compression and each is designed to work with a particular type of data but they all rely on substituting more efficient data storage for repetitive elements.
There are different ways to reduce the amount of space you need to record data. Data Compression can be classified into 2 methods –
Whenever the entire file is compressed, the compression program checks the entire data and applies a special compression algorithm on that data and creates a new file. One of its disadvantages is that this file cannot be used by any software until it comes back to its former state uncompressed, so complete file compression is useful for long-term storage or transportation.
ZIP and ARC are two common compression formats in DOS and Windows. To compress all these formats, the computer needs software that can read compressed files.
Image Compression is lossy or lossless. Lossless compression is sometimes preferred for synthetic images such as technical drawings, icons, or comics, because lossy compression methods use low bit rates, especially when compression artifacts are inserted, while lossy compression is used for high-value content. e.g. may be preferred in image scanners for medical imaging or archive work, while lossy compression may be used especially in applications such as natural images where a small reduction in image quality is acceptable to make up for a large reduction in bit rate. Happens there is done.
In Lossless Compression, the data is compressed and when the same data is decompressed back, it is exactly like the original data. When a text file or program is compressed without any errors, it is called lossless compression.
Even the smallest reduction in quality in image compression sometimes goes unnoticed. There is no particular point up to which compression works well but beyond that it becomes impossible. When there is scope to bear the loss, the compression factor can be high, that is why graphic images can be compressed more than text files or programs.