How do I crop an image using C#?

Question

score 285 · Answer 1 · edited Apr 07 '19 at 15:00

285

Check out this link: http://www.switchonthecode.com/tutorials/csharp-tutorial-image-editing-saving-cropping-and-resizing

private static Image cropImage(Image img, Rectangle cropArea)
{
   Bitmap bmpImage = new Bitmap(img);
   return bmpImage.Clone(cropArea, bmpImage.PixelFormat);
}

edited Apr 07 '19 at 15:00

bato3

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answered Apr 09 '09 at 16:23

Nick

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Agreed, but note that if the cropArea crosses img boundary, it gives a "Out of memory" exception. – ChrisJJ Oct 29 '11 at 14:41
Is this method faster than @DanielLeCheminant method? – Ivan Kochurkin Jan 04 '13 at 22:25
1

@KvanTTT, both of them are pretty slow if you want to crop a big image into smaller ones. – JBeurer Feb 01 '13 at 07:20
1

@ChrisJJ can you explain more? or give a workaround for that issue? – raym0nd Aug 21 '13 at 19:32
1

@raym0nd I'm guessing the workaround is to ensure your rectangle's dimensions are no bigger than the image's – stuartdotnet May 28 '14 at 06:31
@ChrisJJ yes, sorry it took me forever to reply back. – raym0nd Aug 21 '14 at 14:31
4

Their site is down. Anyone got the code from the site? – sangam Sep 03 '15 at 19:58
2

This is the worst solution for performance. Graphics.DrawImage solution is much better. – ElektroStudios Nov 04 '15 at 13:09
It is available through the Wayback Machine: https://web.archive.org/web/20120420110925/http://www.switchonthecode.com/tutorials/csharp-tutorial-image-editing-saving-cropping-and-resizing – Dec 14 '18 at 14:56
So here should you dispose `bmpImage`, or will disposing the clone also dispose the original? – Juan Feb 22 '20 at 19:15
After pondering the more memory-secure alternatives, I ended up wrapping the `.Clone()` in a `try` without further handling, because ignoring the out-of-bounds is intuitive in my use-case. – dakab May 06 '21 at 15:00

score 245 · Accepted Answer · edited Jul 10 '11 at 15:59

245

You can use Graphics.DrawImage to draw a cropped image onto the graphics object from a bitmap.

Rectangle cropRect = new Rectangle(...);
Bitmap src = Image.FromFile(fileName) as Bitmap;
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);
}

edited Jul 10 '11 at 15:59

axk

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answered Apr 09 '09 at 16:23

Daniel LeCheminant

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Just a note, the signature of DrawImage() isn't valid. [It's missing the GraphicsUnit parameter](http://msdn.microsoft.com/en-us/library/ms142040.aspx). – Nathan Taylor Jan 13 '11 at 18:26
2

Also the second argument is the target rect, not the crop rect. – axk Jul 10 '11 at 13:03
8

Is method `DrawImageUnscaledAndClipped` more efficient than `DrawImage` for cropping purpose? – Ivan Kochurkin Jan 04 '13 at 22:27

score 70 · Answer 3 · edited Jul 08 '20 at 17:54

70

Simpler than the accepted answer is this:

public static Bitmap cropAtRect(this Bitmap b, Rectangle r)
{
    Bitmap nb = new Bitmap(r.Width, r.Height);
    using (Graphics g = Graphics.FromImage(nb))
    {
        g.DrawImage(b, -r.X, -r.Y);
        return nb;
    }
}

and it avoids the "Out of memory" exception risk of the simplest answer.

Note that Bitmap and Graphics are IDisposable hence the using clauses.

EDIT: I find this is fine with PNGs saved by Bitmap.Save or Paint.exe, but fails with PNGs saved by e.g. Paint Shop Pro 6 - the content is displaced. Addition of GraphicsUnit.Pixel gives a different wrong result. Perhaps just these failing PNGs are faulty.

edited Jul 08 '20 at 17:54

caesay

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answered Oct 29 '11 at 15:50

ChrisJJ

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Best reply here, this should be awarded the answer. I was experiencing the 'out of memory' as well on other solutions. This worked first time. – c0d3p03t Oct 15 '14 at 21:27
I don't understand why adding GraphicsUnit.Pixel gives the wrong result, but it definitely does. – DOKKA Jun 30 '16 at 15:41
2

My images were cropping with the correct size but at incorrect X/Y until I called SetResolution on the target image as suggested in the answer by @IntellyDev. – Brent Keller May 10 '17 at 12:59
7

This answer leaks the Grphics object. – TaW May 17 '18 at 15:35
3

`Bitmap` and `Graphics` are `IDisposable` - add a `using` clause – Dave Thieben Mar 17 '19 at 14:02
add this: nb.SetResolution(b.HorizontalResolution, b.VerticalResolution); – Dejan Dozet Oct 29 '20 at 20:51
You mention that Paint Shop Pro doesn't work properly. I had the same error in Photoshop, but after saving "Save as web" and 100% quality, it works as it's supposed to. – WoodyDRN May 02 '22 at 09:38

score 10 · Answer 4 · edited May 01 '20 at 17:59

use bmp.SetResolution(image.HorizontalResolution, image .VerticalResolution);

this may be necessary to do even if you implement best answer here especially if your image is real great and resolutions are not exactly 96.0

My test example:

    static Bitmap LoadImage()
    {
        return (Bitmap)Bitmap.FromFile( @"e:\Tests\d_bigImage.bmp" ); // here is large image 9222x9222 pixels and 95.96 dpi resolutions
    }

    static void TestBigImagePartDrawing()
    {
        using( var absentRectangleImage = LoadImage() )
        {
            using( var currentTile = new Bitmap( 256, 256 ) )
            {
                currentTile.SetResolution(absentRectangleImage.HorizontalResolution, absentRectangleImage.VerticalResolution);

                using( var currentTileGraphics = Graphics.FromImage( currentTile ) )
                {
                    currentTileGraphics.Clear( Color.Black );
                    var absentRectangleArea = new Rectangle( 3, 8963, 256, 256 );
                    currentTileGraphics.DrawImage( absentRectangleImage, 0, 0, absentRectangleArea, GraphicsUnit.Pixel );
                }

                currentTile.Save(@"e:\Tests\Tile.bmp");
            }
        }
    }

score 6 · Answer 5 · edited May 06 '10 at 11:24

6

Here's a simple example on cropping an image

public Image Crop(string img, int width, int height, int x, int y)
{
    try
    {
        Image image = Image.FromFile(img);
        Bitmap bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);
        bmp.SetResolution(80, 60);

        Graphics gfx = Graphics.FromImage(bmp);
        gfx.SmoothingMode = SmoothingMode.AntiAlias;
        gfx.InterpolationMode = InterpolationMode.HighQualityBicubic;
        gfx.PixelOffsetMode = PixelOffsetMode.HighQuality;
        gfx.DrawImage(image, new Rectangle(0, 0, width, height), x, y, width, height, GraphicsUnit.Pixel);
        // Dispose to free up resources
        image.Dispose();
        bmp.Dispose();
        gfx.Dispose();

        return bmp;
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
        return null;
    }            
}

edited May 06 '10 at 11:24

Bill the Lizard

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answered Apr 10 '09 at 16:33

PsychoCoder

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He is the only one who mentioned resolution, all the above methods will fail if the source image has non-standard resolution. – net_prog Jan 02 '12 at 20:46
1

use bmp.SetResolution(image .HorizontalResolution, image .VerticalResolution); to fix resolution issue. – Morbia May 23 '12 at 17:40
3

On exception this will leak image, bmp and gfx objects. Why not to wrap those in using statements? – Darius Kucinskas Nov 20 '13 at 20:30

score 5 · Answer 6 · answered Apr 09 '09 at 16:25

5

It's quite easy:

Create a new Bitmap object with the cropped size.
Use Graphics.FromImage to create a Graphics object for the new bitmap.
Use the DrawImage method to draw the image onto the bitmap with a negative X and Y coordinate.

answered Apr 09 '09 at 16:25

Guffa

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It is always better to add some sample code to refer to. Not everyone is a coding expert like you and me! – D J Jul 17 '20 at 13:18

score 4 · Answer 7 · answered Apr 15 '16 at 01:16

4

If you're using AForge.NET:

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

answered Apr 15 '16 at 01:16

Mateen Ulhaq

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GruMu · Answer 8 · 2017-11-08T13:06:13.477

I was looking for a easy and FAST function with no additional libary to do the job. I tried Nicks solution, but i needed 29,4 sec to "extract" 1195 images of an atlas file. So later i managed this way and needed 2,43 sec to do the same job. Maybe this will be helpful.

// content of the Texture class
public class Texture
{
    //name of the texture
    public string name { get; set; }
    //x position of the texture in the atlas image
    public int x { get; set; }
    //y position of the texture in the atlas image
    public int y { get; set; }
    //width of the texture in the atlas image
    public int width { get; set; }
    //height of the texture in the atlas image
    public int height { get; set; }
}

Bitmap atlasImage = new Bitmap(@"C:\somepicture.png");
PixelFormat pixelFormat = atlasImage.PixelFormat;

foreach (Texture t in textureList)
{
     try
     {
           CroppedImage = new Bitmap(t.width, t.height, pixelFormat);
           // copy pixels over to avoid antialiasing or any other side effects of drawing
           // the subimages to the output image using Graphics
           for (int x = 0; x < t.width; x++)
               for (int y = 0; y < t.height; y++)
                   CroppedImage.SetPixel(x, y, atlasImage.GetPixel(t.x + x, t.y + y));
           CroppedImage.Save(Path.Combine(workingFolder, t.name + ".png"), ImageFormat.Png);
     }
     catch (Exception ex)
     {
          // handle the exception
     }
}

score 1 · Answer 9 · edited Jan 31 '13 at 14:57

Cropping an image is very easy in C#. However, doing the stuff how are you going to manage the cropping of your image will be a little harder.

Sample below is the way how to crop an image in C#.

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();

score 1 · Answer 10 · answered Apr 22 '13 at 22:21

There is a C# wrapper for that which is open source, hosted on Codeplex called Web Image Cropping

Register the control

<%@ Register Assembly="CS.Web.UI.CropImage" Namespace="CS.Web.UI" TagPrefix="cs" %>

Resizing

<asp:Image ID="Image1" runat="server" ImageUrl="images/328.jpg" />
<cs:CropImage ID="wci1" runat="server" Image="Image1" 
     X="10" Y="10" X2="50" Y2="50" />

Cropping in code behind - Call Crop method when button clicked for example;

wci1.Crop(Server.MapPath("images/sample1.jpg"));

score 0 · Answer 11 · edited Sep 16 '13 at 09:10

Only this sample working without problem:

var crop = new Rectangle(0, y, bitmap.Width, h);
var bmp = new Bitmap(bitmap.Width, h);
var tempfile = Application.StartupPath+"\\"+"TEMP"+"\\"+Path.GetRandomFileName();


using (var gr = Graphics.FromImage(bmp))
{
    try
    {
        var dest = new Rectangle(0, 0, bitmap.Width, h);
        gr.DrawImage(image,dest , crop, GraphicsUnit.Point);
        bmp.Save(tempfile,ImageFormat.Jpeg);
        bmp.Dispose();
    }
    catch (Exception)
    {


    }

}

score 0 · Answer 12 · edited Feb 25 '15 at 21:21

This is another way. In my case I have:

2 numeric updown controls (called LeftMargin and TopMargin)
1 Picture box (pictureBox1)
1 button that I called generate
1 image on C:\imagenes\myImage.gif

Inside the button I have this code:

Image myImage = Image.FromFile(@"C:\imagenes\myImage.gif");
Bitmap croppedBitmap = new Bitmap(myImage);
croppedBitmap = croppedBitmap.Clone(
            new Rectangle(
                (int)LeftMargin.Value, (int)TopMargin.Value,
                myImage.Width - (int)LeftMargin.Value,
                myImage.Height - (int)TopMargin.Value),
            System.Drawing.Imaging.PixelFormat.DontCare);
pictureBox1.Image = croppedBitmap;

I tried it in Visual studio 2012 using C#. I found this solution from this page

score 0 · Answer 13 · answered Dec 16 '16 at 06:30

here it is working demo on github

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>

C# code logic for upload and crop.

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);
            }
        }
    }
}

score 0 · Answer 14 · answered Apr 09 '09 at 16:29

Assuming you mean that you want to take an image file (JPEG, BMP, TIFF, etc) and crop it then save it out as a smaller image file, I suggest using a third party tool that has a .NET API. Here are a few of the popular ones that I like:

LeadTools
Accusoft Pegasus Snowbound Imaging SDK

How do I crop an image using C#?

14 Answers14

Linked

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