How to crop an image using C

Question

How can I write an application that will crop images in C

User · Answer

There is a C  wrapper for that which is open source  hosted on Codeplex called Web Image Cropping  Register the control   lt    Register Assembly  CS Web UI CropImage  Namespace  CS Web UI  TagPrefix  cs    gt   Resizing   lt asp Image ID  Image1  runat  server  ImageUrl  images 328 jpg    gt   lt cs CropImage ID  wci1  runat  server  Image  Image1        X  10  Y  10  X2  50  Y2  50    gt    Cropping in code behind - Call Crop method when button clicked for example   wci1 Crop Server MapPath  images sample1 jpg

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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  lt  t width  x                   for  int y   0  y  lt  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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

If you re using AForge NET   using var croppedBitmap   new Crop new Rectangle 10  10  10  10   Apply bitmap

User · Answer

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

User · Answer

here it is working demo on github  https   github com SystematixIndore Crop-SaveImageInCSharp   lt    Page Language  C   AutoEventWireup  true  CodeBehind  WebForm1 aspx cs  Inherits  WebApplication1 WebForm1    gt    lt  DOCTYPE html gt   lt html xmlns  http   www w3 org 1999 xhtml  gt   lt head runat  server  gt     lt title gt  lt  title gt    lt link href  css jquery Jcrop css  rel  stylesheet  type  text css    gt   lt script type  text javascript  src  http   ajax googleapis com ajax libs jquery 1 3 jquery min js  gt  lt  script gt   lt script type  text javascript  src  js jquery Jcrop js  gt  lt  script gt   lt  head gt   lt body gt     lt form id  form2  runat  server  gt     lt div gt       lt asp Panel ID  pnlUpload  runat  server  gt         lt asp FileUpload ID  Upload  runat  server    gt         lt br   gt         lt asp Button ID  btnUpload  runat  server  OnClick  btnUpload Click  Text  Upload    gt         lt asp Label ID  lblError  runat  server  Visible  false    gt       lt  asp Panel gt       lt asp Panel ID  pnlCrop  runat  server  Visible  false  gt         lt asp Image ID  imgCrop  runat  server    gt         lt br   gt         lt asp HiddenField ID  X  runat  server    gt         lt asp HiddenField ID  Y  runat  server    gt         lt asp HiddenField ID  W  runat  server    gt         lt asp HiddenField ID  H  runat  server    gt         lt asp Button ID  btnCrop  runat  server  Text  Crop  OnClick  btnCrop Click    gt       lt  asp Panel gt       lt asp Panel ID  pnlCropped  runat  server  Visible  false  gt         lt asp Image ID  imgCropped  runat  server    gt       lt  asp Panel gt     lt  div gt     lt  form gt       lt script type  text javascript  gt    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          lt  script gt   lt  body gt   lt  html gt    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  lt  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

User · Answer

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  quot Out of memory quot  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

User · Answer

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

User · Answer

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

[c#] How to crop an image using C#?

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