PHP 5 in Practice

18. Images Due to its close association with web page generation, an extensive set of libraries has been incorporated into PHP to create and manipulate images. The core set of routines is based on the GD library. Because of the large number ...

18.1. Generating Composite Images with Text One easy and common task is to take an existing image and overlay some text onto it. There are many reasons you might want to do this. Perhaps you want to add automatic captions to your images or insert ...

18.2. Drawing Tips and Tricks The basic functions provided for drawing are easy enough to use and understand: Draw a rectangle, draw a circle, draw a line, and so on. Often you may need to do slight variations on these methods. That can be a littl...

18.3. Using Transparent Backgrounds in Images Transparent backgrounds are useful and available in GIF and PNG graphics formats. Essentially you declare a certain color, your background, to be transparent. This means that anything beneath that ar...

18.4. Creating a Graph/Chart Library If any data, such as temperature versus day or stock market values, is to be presented in a meaningful fashion, it really needs to be presented visually. This usually takes the form of charts. Various forms of ...

18.5. Automatically Creating a Photo Gallery from Digital Camera Files (Exif Data) Digital cameras actually store a Pandora's box of additional information in any JPEG or TIFF that they create. Information about the camera itself and the specifica...