How image compressor works?

Before knowing how it works, you should know what is compress image online. Image compressor is an image optimization tool that is designed for the people to reduce the size of their images that takes unwanted storage on their devices, cloud storage and the bandwidth costs are reduced as well.

The image with 2 million pixels roughly covers 1.97 megabytes on your device that is too much. That image can be compressed to 230 kilobytes that is remarkable because there is no difference in the quality of bigger and lesser sized image. This is the mission and aim of image compressors to provide the best quality image with reduced size.

The image compressor works with two methods. One is the lossless compression and one is lossy image compression. These are techniques of compressing the image according to the file format.

GIF and PNG image formats uses is compressed with lossless compression while the JPG is compressed with the lossy method of compression. The methods vary because of the specifications of the image that makes it compress with only one method either lossless or lossy.

The lossless image compressor reduces the size of the image with few other methods. These methods include DEFLATE method, run-length encoding and Lempel-ziv-welch method.

DEFLATE method

This method lies in the lossless compression, it uses the combination of two algorithms LZ77 and HUFFMAN. The deflate method is used by the image compressors to compress PNG files. The png files are compressed in two processes.

These processes work after one another to reduce the size of image with maintain good quality. The first process is filtering, after it the filtered image is transferred to second process compressing. These two processes give a good quality and reduced size image.

Run-length-encoding

The run-length-encoding method is the lossless compression in image compressors for compressing BMP format files. The run length method compresses the size of image by storing the consecutive values in a single value. The BMP files size is reduced with it by the store of consecutive pixels that won’t be affected if stored as a single value by encoding.

Lempel-ziv-welch

This method of lossless image compression is mainly used for compressing GIF files. The GIF files are different from other image formats as it is only format that supports the animated images. These images are compressed with Lempel-ziv-welch method. This method reduces the size of images with performing limited analysis of data stored in the pixels.

Other than lossless compression, there is a lossy image compression method. It is mainly used for JPG format files. Lossy image compression in image compressors works by reducing the scheme of colors in the JPG images. This method also reduces the size of the image, as from its name you understand that the data is lost in the lossy compression. The decompression is not possible for the lossy image compression