To compress image using an image compressor means to minimize the size of an image file in bytes without lowering the image quality to an unacceptable level. If you compress image online, the decline in the size of the graphics file allows the user to store more images in a given storage space or amount of disk. Use of image compressor also minimizes the time images take to be sent over the internet or downloaded from the internet.
There are a number of ways in which images can be compressed. For internet usage, the two most commonly compressed image file formats are the GIF format and JPEG format. The JPEG compression method is often used by photographs, while the GIF method is usually utilized for other images and line art which involves geometric shapes that are relatively simple.
Other image compression techniques to compress image online include using the wavelets and fractals. These techniques have not yet gained widespread acceptance in the online world. However, JPEG compression technique is promising because its offers high compression ratios to compress JPEG and other image types.
Sometimes the graphics file can be compressed only up to a certain extent without introducing any errors. This is known as the Lossless Compression. Beyond a certain point, errors become inevitable. In cases like that, it is essential that compression be lossless because a single error can damage the meaning or quality of the file. In online image compression, a little loss in the image quality is usually not visible. There isn’t a “critical point” up to which image compressor is known to work correctly. The compression factor tends to be greater when there is some tolerance for loss as compared to when there is no tolerance present. That is why some graphics files can be more than others.