How to use Layui to implement image inversion and brightness adjustment functions

How to use Layui to implement image inversion and brightness adjustment functions

Introduction:
In front-end development, we often encounter problems that require special effects processing for images. Condition. This article will introduce how to use the Layui framework to implement image inversion and brightness adjustment functions, and provide specific code examples for reference.

1. Introduction to Layui:
Layui is an excellent front-end UI framework, which is simple, beautiful, and easy to use. It provides a wealth of front-end components, allowing developers to easily build beautiful websites.

2. Preparation:
Before starting, we need to download the relevant files of the Layui framework and introduce them into the project. Find the download link on the official website (http://www.layui.com/) and follow the documentation instructions to install and configure.

3. Implement the image inversion function:

1. HTML structure:
   First, create a container containing images and buttons in the web page for displaying and operating images. The code is as follows:

<div class="container">
    <img src="/static/imghw/default1.png"  data-src="image.jpg"  class="lazy"  id="image" alt="image">
    <button id="invertBtn" class="layui-btn layui-btn-primary">反色</button>
</div>

2. CSS style:
   In order to make the interface more beautiful, we can add some CSS styles. The code is as follows:

.container {
    position: relative;
    display: inline-block;
}

.container img {
    width: 500px;
    height: auto;
}

.container button {
    position: absolute;
    top: 10px;
    right: 10px;
}

3. JavaScript code:
   Next, we need to write some JavaScript code to implement the image inversion function. The code is as follows:

layui.use('layer', function(){
    var layer = layui.layer;
    
    // 获取图片元素
    var image = document.getElementById('image');

    // 点击按钮时触发反色操作
    document.getElementById('invertBtn').onclick = function() {
        if (image.complete) {
            var canvas = document.createElement('canvas');
            var ctx = canvas.getContext('2d');
            canvas.width = image.width;
            canvas.height = image.height;

            // 将图片绘制到画布上
            ctx.drawImage(image, 0, 0, image.width, image.height);

            // 获取画布数据
            var imageData = ctx.getImageData(0, 0, image.width, image.height);

            // 对每个像素进行反色操作
            for (var i = 0; i < imageData.data.length; i += 4) {
                imageData.data[i] = 255 - imageData.data[i]; // R通道
                imageData.data[i + 1] = 255 - imageData.data[i + 1]; // G通道
                imageData.data[i + 2] = 255 - imageData.data[i + 2]; // B通道
            }

            // 将处理后的数据重新绘制到画布上
            ctx.putImageData(imageData, 0, 0);
        
            // 将画布转为DataURL，并设置为图片的src属性
            image.src = canvas.toDataURL();
        } else {
            layer.msg('图片加载失败');
        }
    };
});

4. Implement the brightness adjustment function:

1. HTML structure:
   Based on the original HTML structure, we add a slider component to To control brightness adjustment. The code is as follows:

<div class="container">
    <img src="/static/imghw/default1.png"  data-src="image.jpg"  class="lazy"  id="image" alt="image">
    <button id="invertBtn" class="layui-btn layui-btn-primary">反色</button>
</div>

    
    亮度调节
    

2. JavaScript code:
   Then, we need to add some JavaScript code to implement the brightness adjustment function. The code is as follows:

layui.use(['layer', 'slider'], function(){
    var layer = layui.layer;
    var slider = layui.slider;
    
    // 获取图片元素
    var image = document.getElementById('image');

    // 点击按钮时触发亮度调节操作
    document.getElementById('brightnessBtn').onclick = function() {
        if (image.complete) {
            // 获取滑块对象
            var brightnessSlider = slider.render({
                elem: '#brightnessRange',
                value: 0,
                min: -100,
                max: 100,
                change: function(value) {
                    var canvas = document.createElement('canvas');
                    var ctx = canvas.getContext('2d');
                    canvas.width = image.width;
                    canvas.height = image.height;

                    // 将图片绘制到画布上
                    ctx.drawImage(image, 0, 0, image.width, image.height);

                    // 获取画布数据
                    var imageData = ctx.getImageData(0, 0, image.width, image.height);

                    // 对每个像素进行亮度调节操作
                    for (var i = 0; i < imageData.data.length; i += 4) {
                        imageData.data[i] += value; // R通道
                        imageData.data[i + 1] += value; // G通道
                        imageData.data[i + 2] += value; // B通道
                    }

                    // 将处理后的数据重新绘制到画布上
                    ctx.putImageData(imageData, 0, 0);

                    // 将画布转为DataURL，并设置为图片的src属性
                    image.src = canvas.toDataURL();
                }
            });
        } else {
            layer.msg('图片加载失败');
        }
    };
});

Summary:
This article introduces how to use the Layui framework to implement image inversion and brightness adjustment functions, and provides specific code examples. By reading this article, you will be able to easily use the Layui framework to implement image special effects processing and increase the visual effects of web pages. Hope this article can be helpful to you!

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