目前QQ空间和新浪微博等社交软件中,分享的图片大多都是添加水印的。添加水印之后的照片也就变得独一无二了,好像就是添加了一个专属的个人签名。可以很好的防止别人盗用你的照片,也能够让别人一看水印就能在上面得到一些关于照片的信息。今天写了一个给图片添加水印的函数,和大家分享一下。有了这个函数,给照片添加水印就显的方便多了。其实原理很简单,原图是一张图片,水印其实也是一张图片,只不过有的水印是白色或透明色背景,然后两张图片进行合成,就成了水印图片。
1.制作水印图片所需php函数(1)getimagesize();
(2)imagecreatefromgif();imagecreatefromjpeg();imagecreatefrompng;
(3)imagecogy();
(4)imagegif();imagejpeg();imagepng();
具体函数如何使用,我就不细讲了,大家可以参考php参考手册
2.代码分享<?phpfunction watermark($maxfile,$minfile){ //获取大小图信息 $maxarr=getimagesize($maxfile); $minarr=getimagesize($minfile); $max_width=$maxarr[0]; $max_height=$maxarr[1]; $max_format=$maxarr[2]; $max_mime=$maxarr['mime']; $min_width=$minarr[0]; $min_height=$minarr[1]; $min_format=$minarr[2]; //$min_mime=$minarr['mime']; //判断大小图格式 switch($max_format){ case 1: $max_createimg="imagecreatefromgif"; $max_outimg="imagegif"; break; case 2: $max_createimg="imagecreatefromjpeg"; $max_outimg="imagejpeg"; break; case 3: $max_createimg="imagecreatefrompng"; $max_outimg="imagepng"; break; } switch($min_format){ case 1: $min_createimg="imagecreatefromgif"; break; case 2: $min_createimg="imagecreatefromjpeg"; break; case 3: $min_createimg="imagecreatefrompng"; break; } //创建大小图资源 $maxim=$max_createimg($maxfile); $minim=$min_createimg($minfile); //两张图的尺寸差 $D_value_x=$max_width-$min_width; $D_value_y=$max_height-$min_height; //添加水印 imagecopy($maxim,$minim,$D_value_x,$D_value_y,0,0,$min_width,$min_height); //保存水印图片 header("content-type:{$max_mime}"); $max_outimg($maxim,"watermark.jpg");}watermark("picture/apple.jpg","picture/copypic.jpg");?>3.说几点代码中可能不太好理解的地方
(1)因为不同格式的图片所需要的函数后缀是不一样的,所以必须在使用函数创建资源和保存水印图片前进行判断图片格式。
(2)计算两个图片的尺寸差,是为了将小图很好的添加到大图的右下角(大多水印都是添加到右下角的吧)。
4.整体可以优化的地方(1)两个switch总觉得有点多了。如果放到if语句或者for循环中,肯定能整合一下。好饿,所以以后在优化这个问题(明显是给自己找借口)。
(2)我用的水印直接是另一张尺寸较小的图片。然而实际的水印大多是一行字,一个网址,一个时间等。可以用做制作验证码的方法,制作水印。然后将水印所需要的文字作为函数的参数,就可以在一张图片中添加自己想要的水印,同时水印的生成也不需要去找图片,完全自动生成。

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.


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

Atom editor mac version download
The most popular open source editor

SublimeText3 Linux new version
SublimeText3 Linux latest version

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

SublimeText3 English version
Recommended: Win version, supports code prompts!

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.