PHP实现根据图片色界在不同位置加水印的方法_PHP
本文实例讲述了PHP实现根据图片色界在不同位置加水印的方法。分享给大家供大家参考。具体如下:
在使用php编程的时候, 很多时候需要对上传的图片加水印,来确定图片版权和出处. 但是,一般情况下加水印的位置是图片的右下角, 但是,不同图片的色阶不同,有时候我们 图片的水印和图片本身色阶相同,就会造成水印不明显.
下面这段代码可以实现自动识别图片的色阶,更加色阶差来添加图片的水印,这样可以避免水印和图片色阶一样的弊端.
<?php function add_wm($nmw_water, $src_file, $output_file, $x, $y) { if(file_exists($output_file)) return; $w1 = MagickGetImageWidth($nmw_water); $h1 = MagickGetImageHeight($nmw_water); $nmw =NewMagickWand(); MagickReadImage($nmw, $src_file); // 默认的加水印位置调整 $lt_w = 50; $lt_h = 50; if($x == 0){ $w = MagickGetImageWidth($nmw); $h = MagickGetImageHeight($nmw); $x = $w; $y = $h; }else{ // 根据具体情况调整 $lt_w = 30; $lt_h = 40; } MagickCompositeImage($nmw, $nmw_water, MW_OverCompositeOp, $x - $w1 - $lt_w, $y - $h1 - $lt_h); MagickWriteImage($nmw, $output_file); DestroyMagickWand($nmw); } // 还是groovy的eachFileRecurse好用啊 function add_wm_recurse($nmw_water, $to_dir, $output_dir, $arr) { $dp = dir($to_dir); while($file=$dp->read()){ if($file != '.' && $file != '..'){ if(is_dir($to_dir . '/' . $file)){ mkdir($output_dir . '/' . $file); add_wm_recurse($nmw_water, $to_dir . '/' . $file, $output_dir . '/' . $file, $arr); }else{ if(!array_key_exists($to_dir . '/' . $file, $arr)){ continue; } $sub_arr = $arr[$to_dir . '/' . $file]; if($sub_arr){ $x = intval($sub_arr[0]); $y = intval($sub_arr[1]); add_wm($nmw_water, $to_dir . '/' . $file, $output_dir . '/' . $file, $x, $y); } } } } $dp->close(); } $to_dir = './resized'; $output_dir = './output'; // 这个是我用java的ImageIO遍历图片像素获取的符合裤子颜色的区域的坐标array(posX, posY) $arr = array( array(50, 50) ); $water = './water.png'; $nmw_water =NewMagickWand(); MagickReadImage($nmw_water, $water); add_wm_recurse($nmw_water, $to_dir, $output_dir, $arr); DestroyMagickWand($nmw_water); ?>
补充:
PHP图像处理模块 MagickWand用法
MagickWand 是一个PHP的模块,用来访问 ImageMagick 的图像处理库。下面是一个使用 MagicWand 的代码片段:
$magick_wand=NewMagickWand(); MagickReadImage($magick_wand,'rose.jpg'); $drawing_wand=NewDrawingWand(); DrawSetFont($drawing_wand,"/usr/share/fonts/bitstream-vera/Vera.ttf"); DrawSetFontSize($drawing_wand,20); DrawSetGravity($drawing_wand,MW_CenterGravity); $pixel_wand=NewPixelWand(); PixelSetColor($pixel_wand,"white"); DrawSetFillColor($drawing_wand,$pixel_wand); if (MagickAnnotateImage($magick_wand,$drawing_wand,0,0,0,"Rose") != 0) { MagickEchoImageBlob( $magick_wand ); } else { echo MagickGetExceptionString($magick_wand); } ?>
安装方法:
1. 下载 php_magickwand_q16_st.dll for 5.2.x
2. 将其放在PHP的扩展目录
3. 在php.ini文件总增加 extension=php_magickwand_q16_st.dll
4. 重新启动apache
希望本文所述对大家的php程序设计有所帮助。

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

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

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

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

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

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

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

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.
