图片处理_.NET_SDK 参考_对象存储 OSS_阿里云技术文档

图片处理是OSS提供的海量、安全、低成本、高可靠的图片处理服务。原始图片上传到OSS后，您可以通过简单的RESTful接口，在任何时间、任何地点、任何互联网设备上对图片进行处理。

图片处理的详细信息请参见OSS图片处理指南。

图片处理功能

OSS图片处理提供以下功能：

获取图片信息
图片格式转换
图片缩放
图片裁剪
图片旋转
图片效果
图片水印，包括添加图片、文字、图文混合水印
自定义图片处理样式
级联处理，调用多个图片处理功能

图片处理使用

图片处理使用标准的HTTP GET请求。您可以在URL的QueryString中设置处理参数。

如果图片文件的访问权限为私有读写，必须通过授权才能进行访问。

匿名访问

您可以通过如下格式的三级域名匿名访问处理后的图片：

http://<yourBucketName>.<yourEndpoint>/<yourObjectName>?x-oss-process=image/<yourAction>,<yourParamValue>


参数	描述
bucket	存储空间名称
endpoint	存储空间所在地域的访问域名
object	图片文件名称
image	图片处理的保留标志符
action	对图片做的操作，如缩放、裁剪、旋转等
param	对图片做的操作所对应的参数

基础操作

例如，将图缩略成宽度为100，高度按比例处理：

http://image-demo.oss-cn-hangzhou.aliyuncs.com/example.jpg?x-oss-process=image/resize,w_100

自定义样式
使用如下格式的三级域名匿名访问图片处理：
```
http://<yourBucketName>.<yourEndpoint>/<yourObjectName>?x-oss-process=style/<yourStyleName>
```
- style：自定义样式的保留标志符。
- yourStyleName：自定义样式名称，即通过控制台自定义样式的规则名称。
例如：
```
http://image-demo.oss-cn-hangzhou.aliyuncs.com/example.jpg?x-oss-process=style/oss-pic-style-w-100
```

级联处理

通过级联处理，可以对一张图片顺序进行多个操作，格式如下：

http://<yourBucketName>.<yourEndpoint>/<yourObjectName>?x-oss-process=image/<yourAction1>,<yourParamValue1>/<yourAction2>,<yourParamValue2>/...

例如：

http://image-demo.oss-cn-hangzhou.aliyuncs.com/example.jpg?x-oss-process=image/resize,w_100/rotate,90

支持HTTPS访问

图片服务支持HTTPS访问，例如：

https://image-demo.oss-cn-hangzhou.aliyuncs.com/example.jpg?x-oss-process=image/resize,w_100

授权访问

授权访问支持自定义样式、HTTPS和级联处理。

以下代码用于生成带签名的图片处理URL：

using Aliyun.OSS;
using Aliyun.OSS.Common;
var endpoint = "<yourEndpoint>";
var accessKeyId = "<yourAccessKeyId>";
var accessKeySecret = "<yourAccessKeySecret>";
var bucketName = "<yourBucketName>";
var objectName = "<yourObjectName>";
// 创建OssClient实例。
var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
try
{
    var process = "image/resize,m_fixed,w_100,h_100";
    var req = new GeneratePresignedUriRequest(bucketName, objectName, SignHttpMethod.Get)
    {
        Expiration = DateTime.Now.AddHours(1),
        Process = process
    };
    // 生成带有签名的URI。
    var uri = client.GeneratePresignedUri(req);
    Console.WriteLine("Generate Presigned Uri:{0} with process:{1} succeeded ", uri, process);
}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

SDK访问

对于任意权限的图片文件，都可以直接使用SDK访问和处理。

SDK处理图片文件支持自定义样式、HTTPS和级联处理。

基础操作

以下代码展示了图片处理的基础操作：

using System;
using System.IO;
using Aliyun.OSS;
using Aliyun.OSS.Common;
using Aliyun.OSS.Util;
namespace ImageProcess
{
    class Program
    {
        static void Main(string[] args)
        {
            Program.ImageProcess();
            Console.ReadKey();
        }
        public static void ImageProcess()
        {
            var endpoint = "<yourEndpoint>";
            var accessKeyId = "<yourAccessKeyId>";
            var accessKeySecret = "<yourAccessKeySecret>";
            var bucketName = "<yourBucketName>";
            var objectName = "<yourObjectName>";
            var localImageFilename = "<yourLocalImageFilename>";
            var downloadDir = "<yourDownloadDir>";
            // 创建OssClient实例。
            var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
            try
            {
                client.PutObject(bucketName, objectName, localImageFilename);
                // 图片缩放
                var process = "image/resize,m_fixed,w_100,h_100";
                var ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-resize.jpg", ossObject.Content);
                // 图片裁剪
                process = "image/crop,w_100,h_100,x_100,y_100,r_1";
                ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-crop.jpg", ossObject.Content);
                // 图片旋转
                process = "image/rotate,90";
                ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-rotate.jpg", ossObject.Content);
                // 图片锐化
                process = "image/sharpen,100";
                ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-sharpen.jpg", ossObject.Content);
                // 图片加水印
                process = "image/watermark,text_SGVsbG8g5Zu-54mH5pyN5YqhIQ";
                ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-watermark.jpg", ossObject.Content);
                // 图片格式转换
                process = "image/format,png";
                ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-format.png", ossObject.Content);
                // 图片信息
                process = "image/info";
                ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-info.txt", ossObject.Content);
                Console.WriteLine("Get Object:{0} with process:{1} succeeded ", objectName, process);
            }
            catch (OssException ex)
            {
                Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
                    ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Failed with error info: {0}", ex.Message);
            }
        }
        private static void WriteToFile(string filePath, Stream stream)
        {
            using (var requestStream = stream)
            {
                using (var fs = File.Open(filePath, FileMode.OpenOrCreate))
                {
                    IoUtils.WriteTo(stream, fs);
                }
            }
        }
    }
}

自定义样式

以下代码用于自定义图片样式：

using System;
using System.IO;
using Aliyun.OSS;
using Aliyun.OSS.Common;
using Aliyun.OSS.Util;
namespace ImageProcessCustom
{
    class Program
    {
        static void Main(string[] args)
        {
            Program.ImageProcessCustomStyle();
            Console.ReadKey();
        }
        public static void ImageProcessCustomStyle()
        {
            var endpoint = "<yourEndpoint>";
            var accessKeyId = "<yourAccessKeyId>";
            var accessKeySecret = "<yourAccessKeySecret>";
            var bucketName = "<yourBucketName>";
            var objectName = "<yourObjectName>";
            var localImageFilename = "<yourLocalImageFilename>";
            var downloadDir = "<yourDownloadDir>";
            // 创建OssClient实例。
            var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
            try
            {
                client.PutObject(bucketName, objectName, localImageFilename);
                // 自定义样式："style/<yourCustomStyleName>"。
                var process = "style/oss-pic-style-w-100";
                var ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-style.jpg", ossObject.Content);
                Console.WriteLine("Get Object:{0} with process:{1} succeeded ", objectName, process);
            }
            catch (OssException ex)
            {
                Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
                    ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Failed with error info: {0}", ex.Message);
            }
        }
        private static void WriteToFile(string filePath, Stream stream)
        {
            using (var requestStream = stream)
            {
                using (var fs = File.Open(filePath, FileMode.OpenOrCreate))
                {
                    IoUtils.WriteTo(stream, fs);
                }
            }
        }
    }
}

级联处理

以下代码用于级联处理图片：

using System;
using System.IO;
using Aliyun.OSS;
using Aliyun.OSS.Common;
using Aliyun.OSS.Util;
namespace ImageProcessCascade
{
    class Program
    {
        static void Main(string[] args)
        {
            Program.ImageProcessCascade();
            Console.ReadKey();
        }
        public static void ImageProcessCascade()
        {
            var endpoint = "<yourEndpoint>";
            var accessKeyId = "<yourAccessKeyId>";
            var accessKeySecret = "<yourAccessKeySecret>";
            var bucketName = "<yourBucketName>";
            var objectName = "<yourObjectName>";
            var localImageFilename = "<yourLocalImageFilename>";
            var downloadDir = "<yourDownloadDir>";
            // 创建OssClient实例。
            var client = new OssClient(endpoint, accessKeyId, accessKeySecret);
            try
            {
                client.PutObject(bucketName, objectName, localImageFilename);
                // 级联处理。
                var process = "image/resize,m_fixed,w_100,h_100/rotate,90";
                var ossObject = client.GetObject(new GetObjectRequest(bucketName, objectName, process));
                WriteToFile(downloadDir + "/sample-style.jpg", ossObject.Content);
                Console.WriteLine("Get Object:{0} with process:{1} succeeded ", objectName, process);
            }
            catch (OssException ex)
            {
                Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID:{2}\tHostID:{3}",
                    ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Failed with error info: {0}", ex.Message);
            }
        }
        private static void WriteToFile(string filePath, Stream stream)
        {
            using (var requestStream = stream)
            {
                using (var fs = File.Open(filePath, FileMode.OpenOrCreate))
                {
                    IoUtils.WriteTo(stream, fs);
                }
            }
        }
    }
}

图片处理工具

您可以通过可视化图片处理工具ImageStyleViewer直观地看到OSS图片处理结果。

图片处理_.NET_SDK 参考_对象存储 OSS

图片处理

图片处理功能

图片处理使用

图片处理工具

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