Image Function_PHP Tutorial
There is a set of image functions in PHP that can dynamically generate image data streams in gif format and output them to the server. In order for this set of functions to work, the system must have the support of the gd library. If it is under Unix, it should be compiled before compiling PHP Obtain the source code of gd and compile it, generate libgd.a and some .h files, and copy them to the system's library directory and header file directory (such as /usr/lib and /usr/include) respectively; if it is under Windows, PHP3 The .0 installation program will install a gd.dll file. Add 'dl("gd.dll");' to the program to use the image function.
The main image functions are:
(1)ImageCreate(width, height)
Returns an image descriptor.
(2)ImageCreateFromGif(file name);
Returns an image descriptor.
(3)ImageColorAllocate (image descriptor, red, green, blue);
Returns a color descriptor. Since the Gif image can only have 256 colors, it must be assigned a palette first. This statement is to assign a palette item.
(4)ImageColorTransparent(image descriptor, color descriptor);
Specify a color as transparent.
(5)ImageArc (image descriptor, circle center abscissa, circle center ordinate, ellipse width, ellipse height, starting angle, ending angle, color descriptor);
ImageChar(image descriptor, font, x, y, character, color descriptor);
ImageCharUp(image descriptor, font, x, y, character, color descriptor);
ImageCopyResized(target image descriptor, source image descriptor, target x, target y, source x, source y, target width, target height, source width, source height);
ImageDashedLine(image descriptor,x1,y1,x2,y2,color descriptor);
ImageFill(image descriptor, starting point x, starting point y, color descriptor);
ImageFilledPolygon(image descriptor, each vertex array, number of vertices, color descriptor);
ImageFilledRectangle(image descriptor,x1,y1,x2,y2,color descriptor);
ImageFillToBorder(image descriptor, starting point x, starting point y, border color, fill color);
ImageLine(image descriptor,x1,y1,x2,y2,color descriptor);
ImagePolygon(image descriptor, each vertex array, number of vertices, color descriptor);
ImageRectangle(image descriptor,x1,y1,x2,y2,color descriptor);
ImageSetPixel(image descriptor, x, y, color descriptor);
ImageString(image descriptor, font, x, y, string, color descriptor);
ImageStringUp(image descriptor, font, x, y, string, color descriptor);
These are all drawing functions. What needs a brief explanation is that the vertex array of the polygon stores the first point x, the first point y, the second point x, the second point y,...
(6)ImageLoadFont(file name);
The file should be a bitmap font file, and a font number is returned. The system defaults to font numbers 1-5, which can be used directly.

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op

This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
