What is the full form of CGI
(i) CGI: Computer Generated Imagery
CGI stands for Computer Generated Imagery. It is an application of computer graphics (imaging software) which is used to create realistic-looking (three-dimensional) images, still and animated visual content, anatomical modeling, architectural design, video game art, special effects in movies and electronic media, etc. In short, it allows you create characters and motion that look real and which may not be created using other methods.
This technique manipulates the environment and creates photorealistic images for the print and electronic media such as movies, videos, games, etc. As CGI visuals are cost-effective than traditional photographic ones, they are widely used throughout the world. A single artist can produce content with CGI without using actors, set pieces or props.
CGI is created with the help of wireframe models. The features like reflection, illumination can be assigned to the wireframes. These features can be modified as per the requirement of the image, and video in order to make them look real. The quality of the visual effects produced by CGI is higher and controllable as compared to physical ones such as creating miniatures for shots, hiring extras for crowd scenes, etc.
How CGI Works:
First, the artists create computer-generated graphics and then to make graphics look real the texture, lighting and color are adjusted. These adjustments make animation look real and not cartoonish. In live-action films the graphics are mixed with the previously filmed scenes. In this case, the lighting on the graphics must match the lighting from the scene to make the finished product seamless.
The CGI was used for the first in a movie in 1973; Michael Crichton's "Westworld". After few years, it was used in a movie "Star Wars." In 1993, it was used in the movie "Jurassic Park". There are many other movies which made good use of CGI such as Avatar, Lord of the Rings, Inception, Finding Nemo, The Matrix, and more.
(ii) CGI: Common Gateway Interface
CGI stands for Common Gateway Interface. It is a technology that enables a web browser to submit forms and connect to programs over a web server. It is the best way for a web server to send forms and connect to programs on the server. CGI can also be described as a set of standards or rules where a program or script can send data back to the webserver where it can be processed.
So, it is an interface for running executable via a web server. In general, it means taking an HTTP request and passing it to an application in order to deliver a dynamically generated HTML page back to a browser. However, any program that can run on a web server is usable as a CGI script. Generally, CGI programs are used to generate pages dynamically or to perform some other action when someone fills out an HTML form and clicks the submit button. CGI applications can be written in any programming language, some of which are Perl, PHP, and Python.
How CGI works?
The browser sends a URL that causes the AOL server to use CGI to run a program. The browser runs on a client machine exchanges information with a Web server using the HyperText Transfer Protocol or HTTP. Depending on the type of request from the browser, the web server may provide a document from its own document directory or executes a CGI program which means it passes the input from the reader (browser) to the program and output from the program back to the reader (browser). Thus, CGI works as a gateway between the AOL server and the program you write.
The steps involved in creating a dynamic HTML document on the fly through CGI are as follows: