Resize all images in a directory

Question

i have to resize image of a directory,

but i am getting error, access denied, on this line

System.IO.File.Delete(_path);

i know it is because the image i read is in used, but dont know how to handle it

I have found links on SO, but all are in php :-(

for (int i = 1; i < dt.Rows.Count; i++)
{
    try
    {
        string _ImageUrl = HttpContext.Current.Request.PhysicalApplicationPath + 
            "Data\\" + dt.Rows[i]["ProductImage"].ToString();

        string _extName = System.IO.Path.GetExtension(_ImageUrl);

        System.Drawing.Image _productImage = ImageReSize(_ImageUrl, 500);
        string _path = _ImageUrl;

        if (System.IO.File.Exists(_path))
        System.IO.File.Delete(_path);

        _productImage.Save(_path);

        _productImage = ImageReSize(_ImageUrl, 85);
        string _strImageName2 = dt.Rows[i]["ProductSmallImage"].ToString();

        _path = HttpContext.Current.Request.PhysicalApplicationPath + 
            "Data\\" + _strImageName2;

        if (System.IO.File.Exists(_path))
        System.IO.File.Delete(_path);
        _productImage.Save(_path);
    }
}

code of resize

 public System.Drawing.Image ImageReSize(string _imageUrl, int Width)
    {
        try
        {
            //uploadImageFile.PostedFile.InputSteam
            System.Drawing.Image oImg = System.Drawing.Image.FromFile(_imageUrl);

            //((oh *nw) / ow)*100

            int Height = ((oImg.Height * Width) / oImg.Width);              // (oImg.Width * Width);
            Size PictureThumbSize = new Size();
            PictureThumbSize.Height = Height;
            PictureThumbSize.Width = Width;
            System.Drawing.Image oThumbNail = new Bitmap(PictureThumbSize.Width, PictureThumbSize.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

            Graphics oGraphic = Graphics.FromImage(oThumbNail);

            oGraphic.CompositingQuality = CompositingQuality.HighQuality;

            oGraphic.SmoothingMode = SmoothingMode.HighQuality;

            oGraphic.InterpolationMode = InterpolationMode.HighQualityBicubic;

            Rectangle oRectangle = new Rectangle(0, 0, PictureThumbSize.Width, PictureThumbSize.Height);

            oGraphic.DrawImage(oImg, oRectangle);
            oImg.Dispose();
            return oThumbNail;
            //oThumbNail.Save(sPhysicalPath + @"\" + newFileName, ImageFormat.Jpeg);
        }
        catch (Exception Ex)
        {
            return null;
        }
    }

What does your `ImageReSize` method do? Can you share some code, especially how you open/close the image files? — kdrvn, Jul 16 '13 at 09:41
ImageResize code is working fine, if i dont delete the file and save with other name then its working fine, problem is i have to give same name (replace older image) — Your father, Jul 16 '13 at 09:42
Does the user account your program is running under have access to the file it is trying to delete? — Liam, Jul 16 '13 at 09:53
when i dint read file and delete simply, its deleted, so i think main problem is its being used some where, i did dispose but its not wroking — Your father, Jul 16 '13 at 09:58

score 1 · Answer 1 · edited May 23 '17 at 12:05

First you don't have to delete the file before save, the function Image.Save() will replace the existing image but you have to make sure to dispose all handles pointing to the image. here is an example to explain my point:

      var image = new Bitmap("test.png");

      var image2 = resizeImage(image, new Size(48, 48));
      //image.Dispose();
      image2.Save("test.png");

Without the dipose you will have an exeption, but if you uncomment the line image.Dispose() it will work like a charm.

for the function resizeImage I copied it for the question Resize an Image C#

and here is the code:

public static Image resizeImage(Image imgToResize, Size size)
{
  return (Image)(new Bitmap(imgToResize, size));
}

EDIT:

It seems that the Graphics object is the reason, you have to call oGraphic.Dispose();

Call the _productImage.Dispose() after the save.

In fact a more proper way is :

  for (int i = 1; i < dt.Rows.Count; i++)
  {
    try
    {
      string _ImageUrl = HttpContext.Current.Request.PhysicalApplicationPath +
          "Data\\" + dt.Rows[i]["ProductImage"].ToString();

      string _extName = System.IO.Path.GetExtension(_ImageUrl);

      using (System.Drawing.Image _productImage = ImageReSize(_ImageUrl, 500))
      {
        string _path = _ImageUrl;

        if (System.IO.File.Exists(_path))
          System.IO.File.Delete(_path);

        _productImage.Save(_path);
      }
      using (System.Drawing.Image _productImage = ImageReSize(_ImageUrl, 85))
      {
        string _strImageName2 = dt.Rows[i]["ProductSmallImage"].ToString();

        _path = HttpContext.Current.Request.PhysicalApplicationPath +
            "Data\\" + _strImageName2;

        if (System.IO.File.Exists(_path))
          System.IO.File.Delete(_path);
        _productImage.Save(_path);
      }
    }
    catch
    {
      //Handle the exeption
    }
  }

public System.Drawing.Image ImageReSize(string _imageUrl, int Width)
{

  try
  {
    //uploadImageFile.PostedFile.InputSteam
    using (System.Drawing.Image oImg = System.Drawing.Image.FromFile(_imageUrl))
    //((oh *nw) / ow)*100
    {
      int Height = ((oImg.Height * Width) / oImg.Width);              // (oImg.Width * Width);
      Size PictureThumbSize = new Size();
      PictureThumbSize.Height = Height;
      PictureThumbSize.Width = Width;
      System.Drawing.Image oThumbNail = new Bitmap(PictureThumbSize.Width, PictureThumbSize.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

      using (Graphics oGraphic = Graphics.FromImage(oThumbNail))
      {
        oGraphic.CompositingQuality = CompositingQuality.HighQuality;

        oGraphic.SmoothingMode = SmoothingMode.HighQuality;

        oGraphic.InterpolationMode = InterpolationMode.HighQualityBicubic;

        Rectangle oRectangle = new Rectangle(0, 0, PictureThumbSize.Width, PictureThumbSize.Height);

        oGraphic.DrawImage(oImg, oRectangle);
      }
      return oThumbNail;
    }
    //oThumbNail.Save(sPhysicalPath + @"\" + newFileName, ImageFormat.Jpeg);
  }
  catch (Exception Ex)
  {
    return null;
  }

}

yeah @dav_i, you have a point since the code like that is bound to have an unexpected outcome. — Swift, Jul 16 '13 at 10:14

score 1 · Answer 2 · answered Jul 16 '13 at 10:10

1

Call Dispose on your Graphics object as well.

answered Jul 16 '13 at 10:10

dotNET

33,414
24
162
251

score 0 · Answer 3 · answered Jul 16 '13 at 09:49

0

Call Dispose on your original image before trying to delete it.

answered Jul 16 '13 at 09:49

Tamim Al Manaseer

3,554
3
24
33

Yes it did, still same problem – Your father Jul 16 '13 at 09:51

Resize all images in a directory

3 Answers3