Image rotate

Question

User1587254688 posted
I want to rotate image and save it but it gives an error like this; GDI+ generic error... Can you help? Thanks.

1    protected void Page_Load(object sender, EventArgs e)
2        {
3            string yol = Server.MapPath("a.jpg");
4            System.Drawing.Image resim = System.Drawing.Image.FromFile(yol);
5            resim = cevir((Bitmap)resim, 270);
6            resim.Save(yol);
7            resim.Dispose();
8            resim = null;
9        }
10   
11       public static Bitmap cevir(Bitmap b, float angle)
12       {
13           //create a new empty bitmap to hold rotated image
14           Bitmap returnBitmap = new Bitmap(b.Width, b.Height);
15           //make a graphics object from the empty bitmap
16           Graphics g = Graphics.FromImage(returnBitmap);
17           //move rotation point to center of image
18           g.TranslateTransform((float)b.Width / 2, (float)b.Height / 2);
19           //rotate
20           g.RotateTransform(angle);
21           //move image back
22           g.TranslateTransform(-(float)b.Width / 2, -(float)b.Height / 2);
23           //draw passed in image onto graphics object
24           g.DrawImage(b, new Point(0, 0));
25           g.Dispose();
26   
27           return returnBitmap;
28       }

 

 

Answer 1

User187056398 posted

From the online help on FromImage:

    The file remains locked until the Image is disposed.

You are never disposing the original image.  You can save to a new file name, or create separate objects and dispose the original before saving the new one.

 

Answer 2

User1587254688 posted
I've changed it but it doesn't works [:(] Is this code correct?

1    string yol = Server.MapPath("a.jpg");
2            System.Drawing.Image resim = System.Drawing.Image.FromFile(yol);
3            resim = cevir((Bitmap)resim, 270);
4            resim.Save(Server.MapPath("b.jpg"));
5            resim.Dispose();
6            resim = null;
7            File.Delete(Server.MapPath("a.jpg"));
8            File.Move(Server.MapPath("b.jpg"), Server.MapPath("a.jpg"));

 

 

Answer 3

User187056398 posted

No.  In these lines

2            System.Drawing.Image resim = System.Drawing.Image.FromFile(yol);
3            resim = cevir((Bitmap)resim, 270);

You have a reference to an Image called resim that is lurking in memory.

Then you re-assign the reference to a new image returned from your function.  This 'abandons' the first image.  Eventually something will time out and the resource will be released but it's not want you want.

 

Answer 4

User1587254688 posted

 So, how can I release the fist image? Or is there another way like working on memory?

Answer 5

User1587254688 posted

  Now it's working with oku function. But it doesn't compress the jpeg file. How can I compress it?

 

1    using System;
2    using System.Collections.Generic;
3    using System.Linq;
4    using System.Web;
5    using System.Web.UI;
6    using System.Web.UI.WebControls;
7    using System.Drawing;
8    using System.IO;
9    
10   public partial class _Default : System.Web.UI.Page 
11   {
12       public static System.Drawing.Image oku(string fileName)
13       {
14           System.Drawing.Image theImage = null;
15           using (FileStream fileStream = new FileStream(fileName, FileMode.Open,
16           FileAccess.Read))
17           {
18               byte[] img;
19               img = new byte[fileStream.Length];
20               fileStream.Read(img, 0, img.Length);
21               fileStream.Close();
22               theImage = System.Drawing.Image.FromStream(new MemoryStream(img));
23               img = null;
24           }
25           GC.Collect();
26           return theImage;
27       }
28   
29       protected void Page_Load(object sender, EventArgs e)
30       {
31           string yol = Server.MapPath("a.jpg");
32           System.Drawing.Image resim = oku(Server.MapPath("a.jpg")); ;
33           resim.RotateFlip(RotateFlipType.Rotate90FlipNone);
34           resim.Save(Server.MapPath("a.jpg"));
35           resim.Dispose();
36           resim = null;
37       }
38   }
39   

 

Answer 6

User187056398 posted

But it doesn't compress the jpeg file. How can I compress it?

Here's a sample: http://www.vbforums.com/showthread.php?t=343060

 

Answer 7

User187056398 posted

By the way,  you may find this technique helpful...

        String ImagePath = MapPath(@"~\Images\April2.jpg");

        System.Drawing.Image MyImage = System.Drawing.Image.FromFile(ImagePath);

        MyImage.RotateFlip(RotateFlipType.Rotate270FlipX);
        MyImage.Save(ImagePath);