JPEG is the acronym corresponding to Joint Photographic Experts Group , a committee of specialists that devised a standard of coding and digital image compression . JPEG it is also the denomination of Format that identifies these types of documents and the extension of the files in question.
It can be said, therefore, that JPEG is a method to compress the images and also a file format. Most current cameras, for example, work with JPEG files .
He algorithm compression used by the JPEG It makes it possible to reduce the weight (size) of image files, while also reducing their quality. The compressed image, thus, is not identical to the original image.
He JPEG format allows to define the degree of compression. The greater the degree of compression, the greater the loss of quality and smaller file size. Therefore, if the image is compressed little, the loss of quality will be limited, although the file size will still be large.
Many times there is confusion between JPEG and JPG . In this sense we must say JPG is the format used in the operating system Windows And in the PC , which usually work with extensions of three characters. But both notions allude to the same: to this method of compression of digital images.
Numerous images that we found in the websites are JPEG . However, there are other formats that are also popular, such as PNG and GIF , each with its own characteristics. The choice of one or another format will depend on the needs of the contents.
In this sense, an advice extended by experts in image and design is to try several formats before deciding on one, at least in a draft Very different from what we have done so far. Once we know the pros and cons of each one, we can develop a certain degree of intuition that allows us to know in advance what suits us for each type of work.
With respect to PNG, we can say that it is a graphic format that allows compressing images with an algorithm that does not generate lost any. Since the mid-1990s, we can save our graphic documents with this extension to ensure that the result is satisfactory. In addition to image quality and color depth, PNG gives us the ability to store transparent pixels, unlike JPEG.
The temptation to use PNG is very great as soon as we find out about all this: what is the benefit of wasting time adjusting the file size when saving it if PNG offers us the best quality, besides the possibility of including transparencies? Well, the answer is that both formats They have been created with different goals in mind.
While it is true that the compression chosen for a JPEG file greatly affects its quality, the ideal is to use it for very large images and photographs, while PNG was designed for documents that contain considerable spaces of a single color or with little color variations and for Internet storage When preparing a file for your Print On paper, PNG is not as useful but JPEG is preferred, among others.
The algorithm used by JPEG to compress the images is based on two phenomena of our own view : on the one hand, our eyes are considerably more sensitive to the change in luminance than that of chrominance, that is, they perceive changes in brightness more easily than those in color; on the other, the changes in brightness are best seen in parts of the image where there are few variations.