Secrets of Web Graphics
It is known that a person receives 70% of information about the world through eyesight. Naturally, with the advent of graphical browsers, with the ability to add image to the text, Internet acquired a powerful tool to influence its users. Being essentially the same as computer graphics, images on the web still have a number of features that should be given attention.
In web graphics the depth of colors is determined by the number of bits used per pixel. In fact, color depth, and accordingly, the number of colors in the palette can be arbitrarily large. But do not forget the saying “Everything in moderation”. You also need to take into account the speed of calculation of the large volume of images by the computer and monitor features at a great depth of color. Hence, we come to the maximum – 24 bits per pixel or 16.8 million colors in the palette. It is not always appropriate to use the “full” palette when preparing images for the web.
The use of black-and-white images has also become trendy recently as there is no need to keep information about all the colors, but only the information on the shades of the same color is stored. However, for images with full range of colors with smooth gradient you need to apply RGB (red, green and blue) mode, giving access to the management of all the colors.
Images in computer graphics can be divided into two broad classes: raster and vector ones.
The principle of construction of raster images is based on the finite resolution of the eye, when approaching two points, the eye ceases to distinguish between them. Raster images can be represented as an array of pixels, each of which has its color. Any elementary unit, that is pixel, is indivisible which makes impossible to scale the raster image. With raster images you can get full access to every pixel in the image, change the brightness, hue or saturation, change white to black. It is the basis for multiple graphic filters to make the image blurry or more dramatic, more or less contrasty.
Vector is the opposite of the raster. Here there is no need to describe each pixel which significantly reduces the amount of files, even for fairly large image sizes. Furthermore, vector image is an ideal target for scaling. Image enlarged ten times will look as good as the original one. One variety of vector species is the three-dimensional (3D) graphics.
Despite the variety of graphic formats only a small number of them are used, mainly GIF and JPEG. Both raster formats are supported by all graphical browsers by ‘default’ and can be handled in most image editors. Choosing between the formats is defined by features of a particular image.
Three-dimensional objects also make a part of web graphics. For their creation VRML 1.0 was presented in 1994 allowing you to create complex virtual worlds with sound effects.