Joint Photographic Experts Group

We continue seeing what file formats use for each particular case, and its comparative advantages. The archives with format JPEG of denominate thus, again, like product of the first letters of Joint Photographic Experts Group. Get more background information with materials from Viktor Mayer-Schönberger. Its popularity began with the era of the digital photography, because all the digital cameras or the majority of them record their photos with this format. The fundamental characteristic of this format is that although for example when happening of a format is loss of quality bmp to JPEG, the same can be administered graduating the level as compression of the file, which makes it highly versatile. Images JPEG are based on the system of colors RGB (network, green, blue that is to say, red, green and blue), thus the images compose their variation of color in the major or minor degree of these three components.

By this cause, and the excessive loss of quality to that it is arrived when the image is extended, it is not recommended to work printed texts. For that reason, the graphical designers when they make design of forms, do not use this format. But for images of sites, it is a format more than adapted, since good visual quality with little relative weight is obtained. Finally, format png (Portable Graphics Network) is the one of more recent development. It has been designed by Adobe, and the basic program to work these graphs is the Fireworks, although there are many others.

The quality is very high, but usually he is a little heavier than a GIF or a JPEG. Nevertheless, it is becoming more and more popular because it admits transparencies. That is to say, a graph in format png with a transparent bottom can be designed, and this way, when placing it on a bottom of plotted color or, no longer we would be limited square or rectangular images. When admitting the transparencies, we can design irregular images, and soon when placing them in the site, the part of file without image does not take any color, that is to say, is transparent. The png in if also he is square or rectangular like the other, but disguises, because we can place what we want, with any form, but the spaces without drawing take the color from the bottom. When we included a graph in a Web site, we do not have to drain the size so that it enters our design of page we designed while it, that is to say, draining it when placing it. The best thing is to reduce it with a good publisher of images (like the Photoshop, or the Fireworks) and to give him to the size and the necessary resolution before including it in the page. When including images in a page Web, we must place tags to him as it corresponds, that is to say, include name of the image, description and alternative text (that small yellow cartelito that appears when happening the mouse exceeds she). All these factors contribute to a good indexing of the site, since they are textual elements that are read by crawlers. By this, it agrees to put to the image a name to him that includes some of keywords of the site, or at least an excellent name, thus avoiding names like 12335.jpeg, and including something like printer-deskjet-Epson-RX4500.