


Website optimization cannot just focus on the code. Content is also one of the most important objects of the website, and images are the most important content of the website. The most important thing to deal with when optimizing images is to automatically scale all large images uploaded to the website into small images (the size is sufficient for the web page), so as to reduce the storage space by N times and increase the speed of downloading and browsing. Therefore, the task of scaling images into a dynamic website must be processed. It is often tied to file upload and can be resized while uploading images. Of course, sometimes it is necessary to handle image scaling separately. For example, when making a picture list, if you directly use a large image and only zoom it into a small image when it is displayed, this will not only slow down the download speed, but also reduce the page response time. Usually when encountering such an application, when uploading a picture, a small icon specially used for making a list is scaled for the picture. When this small icon is clicked, the large picture will be downloaded for browsing.
When using the GD library to process image scaling, you usually use one of the two functions imagecopyresized() and imagecopyresampled(). The quality will be better after using the imagecopyresampled() function. Here we only introduce how to use the imagecopyresampled() function. The prototype of this function is as follows:
bool imagecopyresampled(resource dst_image,resource src_image,int dst_x,int dst_y,int src_x,int src_y,int dst_w,int dst_h ,int src_w,int src_h)
This function copies a square area from one image to another, smoothly interpolating pixel values, thus reducing the size of the image while still maintaining minimal High definition. Returns TRUE if successful, FALSE if failed. The parameters dst_image and src_image are the identifiers of the target image and source image respectively. If the source and target have different widths and heights, the image will be shrunk and stretched accordingly, with coordinates referring to the upper left corner. This function can be used to copy within the same image (if dst_image and src_image are the same) but if the areas overlap, the results are unpredictable. In the following example, taking the JPEG image format as an example, write an image scaling function thumb(). The code is as follows:
<?php //用于对图片进行缩放 function thumb($filename,$width=200,$height=200){ //获取原图像$filename的宽度$width_orig和高度$height_orig list($width_orig,$height_orig) = getimagesize($filename); //根据参数$width和$height值,换算出等比例缩放的高度和宽度 if ($width && ($width_orig<$height_orig)){ $width = ($height/$height_orig)*$width_orig; }else{ $height = ($width / $width_orig)*$height_orig; } //将原图缩放到这个新创建的图片资源中 $image_p = imagecreatetruecolor($width, $height); //获取原图的图像资源 $image = imagecreatefromjpeg($filename); //使用imagecopyresampled()函数进行缩放设置 imagecopyresampled($image_p,$image,0,0,0,0,$width,$height,$width_orig,$height_orig); //将缩放后的图片$image_p保存,100(质量最佳,文件最大) imagejpeg($image_p,$filename); imagedestroy($image_p); imagedestroy($image); } thumb("brophp.jpg",100,100); ?>
More articles related to PHP image processing examples of image scaling using the imagecopyresampled function Please pay attention to PHP Chinese website!

Laravel simplifies handling temporary session data using its intuitive flash methods. This is perfect for displaying brief messages, alerts, or notifications within your application. Data persists only for the subsequent request by default: $request-

This is the second and final part of the series on building a React application with a Laravel back-end. In the first part of the series, we created a RESTful API using Laravel for a basic product-listing application. In this tutorial, we will be dev

The PHP Client URL (cURL) extension is a powerful tool for developers, enabling seamless interaction with remote servers and REST APIs. By leveraging libcurl, a well-respected multi-protocol file transfer library, PHP cURL facilitates efficient execution of various network protocols, including HTTP, HTTPS, and FTP. This extension offers granular control over HTTP requests, supports multiple concurrent operations, and provides built-in security features.

Laravel provides concise HTTP response simulation syntax, simplifying HTTP interaction testing. This approach significantly reduces code redundancy while making your test simulation more intuitive. The basic implementation provides a variety of response type shortcuts: use Illuminate\Support\Facades\Http; Http::fake([ 'google.com' => 'Hello World', 'github.com' => ['foo' => 'bar'], 'forge.laravel.com' =>

Do you want to provide real-time, instant solutions to your customers' most pressing problems? Live chat lets you have real-time conversations with customers and resolve their problems instantly. It allows you to provide faster service to your custom

In this article, we're going to explore the notification system in the Laravel web framework. The notification system in Laravel allows you to send notifications to users over different channels. Today, we'll discuss how you can send notifications ov

Article discusses late static binding (LSB) in PHP, introduced in PHP 5.3, allowing runtime resolution of static method calls for more flexible inheritance.Main issue: LSB vs. traditional polymorphism; LSB's practical applications and potential perfo

PHP logging is essential for monitoring and debugging web applications, as well as capturing critical events, errors, and runtime behavior. It provides valuable insights into system performance, helps identify issues, and supports faster troubleshoot


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

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

WebStorm Mac version
Useful JavaScript development tools

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
