如何使用c#裁剪图像?

当前回答

如果你在使用AForge。NET:

using(var croppedBitmap = new Crop(new Rectangle(10, 10, 10, 10)).Apply(bitmap))
{
    // ...
}

2016-04-15 01:16:36

其他回答

这里是github上的工作演示

https://github.com/SystematixIndore/Crop-SaveImageInCSharp

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication1.WebForm1" %>

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
  <title></title>
 <link href="css/jquery.Jcrop.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>
<script type="text/javascript" src="js/jquery.Jcrop.js"></script>
</head>
<body>
  <form id="form2" runat="server">
  <div>
    <asp:Panel ID="pnlUpload" runat="server">
      <asp:FileUpload ID="Upload" runat="server" />
      <br />
      <asp:Button ID="btnUpload" runat="server" OnClick="btnUpload_Click" Text="Upload" />
      <asp:Label ID="lblError" runat="server" Visible="false" />
    </asp:Panel>
    <asp:Panel ID="pnlCrop" runat="server" Visible="false">
      <asp:Image ID="imgCrop" runat="server" />
      <br />
      <asp:HiddenField ID="X" runat="server" />
      <asp:HiddenField ID="Y" runat="server" />
      <asp:HiddenField ID="W" runat="server" />
      <asp:HiddenField ID="H" runat="server" />
      <asp:Button ID="btnCrop" runat="server" Text="Crop" OnClick="btnCrop_Click" />
    </asp:Panel>
    <asp:Panel ID="pnlCropped" runat="server" Visible="false">
      <asp:Image ID="imgCropped" runat="server" />
    </asp:Panel>
  </div>
  </form>
    <script type="text/javascript">
  jQuery(document).ready(function() {
    jQuery('#imgCrop').Jcrop({
      onSelect: storeCoords
    });
  });

  function storeCoords(c) {
    jQuery('#X').val(c.x);
    jQuery('#Y').val(c.y);
    jQuery('#W').val(c.w);
    jQuery('#H').val(c.h);
  };

</script>
</body>
</html>

用于上传和裁剪的c#代码逻辑。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using SD = System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;

namespace WebApplication1
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        String path = HttpContext.Current.Request.PhysicalApplicationPath + "images\\";
        protected void Page_Load(object sender, EventArgs e)
        {

        }
        protected void btnUpload_Click(object sender, EventArgs e)
        {
            Boolean FileOK = false;
            Boolean FileSaved = false;

            if (Upload.HasFile)
            {
                Session["WorkingImage"] = Upload.FileName;
                String FileExtension = Path.GetExtension(Session["WorkingImage"].ToString()).ToLower();
                String[] allowedExtensions = { ".png", ".jpeg", ".jpg", ".gif" };
                for (int i = 0; i < allowedExtensions.Length; i++)
                {
                    if (FileExtension == allowedExtensions[i])
                    {
                        FileOK = true;
                    }
                }
            }

            if (FileOK)
            {
                try
                {
                    Upload.PostedFile.SaveAs(path + Session["WorkingImage"]);
                    FileSaved = true;
                }
                catch (Exception ex)
                {
                    lblError.Text = "File could not be uploaded." + ex.Message.ToString();
                    lblError.Visible = true;
                    FileSaved = false;
                }
            }
            else
            {
                lblError.Text = "Cannot accept files of this type.";
                lblError.Visible = true;
            }

            if (FileSaved)
            {
                pnlUpload.Visible = false;
                pnlCrop.Visible = true;
                imgCrop.ImageUrl = "images/" + Session["WorkingImage"].ToString();
            }
        }

        protected void btnCrop_Click(object sender, EventArgs e)
        {
            string ImageName = Session["WorkingImage"].ToString();
            int w = Convert.ToInt32(W.Value);
            int h = Convert.ToInt32(H.Value);
            int x = Convert.ToInt32(X.Value);
            int y = Convert.ToInt32(Y.Value);

            byte[] CropImage = Crop(path + ImageName, w, h, x, y);
            using (MemoryStream ms = new MemoryStream(CropImage, 0, CropImage.Length))
            {
                ms.Write(CropImage, 0, CropImage.Length);
                using (SD.Image CroppedImage = SD.Image.FromStream(ms, true))
                {
                    string SaveTo = path + "crop" + ImageName;
                    CroppedImage.Save(SaveTo, CroppedImage.RawFormat);
                    pnlCrop.Visible = false;
                    pnlCropped.Visible = true;
                    imgCropped.ImageUrl = "images/crop" + ImageName;
                }
            }
        }

        static byte[] Crop(string Img, int Width, int Height, int X, int Y)
        {
            try
            {
                using (SD.Image OriginalImage = SD.Image.FromFile(Img))
                {
                    using (SD.Bitmap bmp = new SD.Bitmap(Width, Height))
                    {
                        bmp.SetResolution(OriginalImage.HorizontalResolution, OriginalImage.VerticalResolution);
                        using (SD.Graphics Graphic = SD.Graphics.FromImage(bmp))
                        {
                            Graphic.SmoothingMode = SmoothingMode.AntiAlias;
                            Graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
                            Graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
                            Graphic.DrawImage(OriginalImage, new SD.Rectangle(0, 0, Width, Height), X, Y, Width, Height, SD.GraphicsUnit.Pixel);
                            MemoryStream ms = new MemoryStream();
                            bmp.Save(ms, OriginalImage.RawFormat);
                            return ms.GetBuffer();
                        }
                    }
                }
            }
            catch (Exception Ex)
            {
                throw (Ex);
            }
        }
    }
}

2016-12-16 06:30:02

这很简单:

创建一个裁剪大小的新位图对象。使用图形。为新的位图创建一个图形对象。使用DrawImage方法将图像绘制到具有负X和负Y坐标的位图上。

2009-04-09 16:25:50

在c#中裁剪图像非常简单。然而，做的东西，你将如何管理裁剪你的图像将会有点困难。

下面的示例是如何在c#中裁剪图像的方法。

var filename = @"c:\personal\images\horizon.png";
var img = Image.FromFile(filename);
var rect = new Rectangle(new Point(0, 0), img.Size);
var cloned = new Bitmap(img).Clone(rect, img.PixelFormat);
var bitmap = new Bitmap(cloned, new Size(50, 50));
cloned.Dispose();

2013-01-18 07:57:03

你可以使用[图形。使用DrawImage][1]将裁剪图像从位图绘制到图形对象上。

Rectangle cropRect = new Rectangle(...);
using (Bitmap src = Image.FromFile("") as Bitmap)
{
    using (Bitmap target = new Bitmap(cropRect.Width, cropRect.Height))
    {
        using (Graphics g = Graphics.FromImage(target))
        {
            g.DrawImage(src, new Rectangle(0, 0, target.Width, target.Height),
                cropRect,
                GraphicsUnit.Pixel);
        }
    }
}

2009-04-09 16:23:31

如果你在使用AForge。NET:

using(var croppedBitmap = new Crop(new Rectangle(10, 10, 10, 10)).Apply(bitmap))
{
    // ...
}

2016-04-15 01:16:36

如何使用c#裁剪图像?

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