Issue in resizeing an image to thumbnail size

Question

i have an image where i am resizing the image into thumbnail size it works fine if i am using an image size[700(width)* 600(height)] orignal size lets say i have 10 images of theis size

but if i use an image around size[1100*1200] orignal size it resize the image into thumbnail but doesnot match the size of the other thubnail image

when show in listview control all the images which are size in [700* 600] are shown in one size

image which is in size in [1100* 1200] are shown in one size[slighty smaller than other images]

so when i am displaying the image in listview control so this looks out all 10 images are shown in one size but one image is shown in a smaller size

and some times all the images are loaded fine

but some images are not shown only few images out 10 images 2 images sre not shown

System.Drawing.Image objImage = System.Drawing.Bitmap.FromFile(System.Web.HttpContext.Current.Server.MapPath(@"Images\" + sImageFileName));
if (sImageFileName != null)
{
    if (iThumbSize == 1)
    {

        dHeight = objImage.Height;
        dWidth = objImage.Width;
        dNewHeight = 100;
        dNewWidth = 100;
        objImage = objImage.GetThumbnailImage((int)dNewWidth, (int)dNewHeight, new System.Drawing.Image.GetThumbnailImageAbort(callback), new IntPtr());
}

this i the code what i am using i am setting the size height and width to 100

any help would be great thank you

Answer 1

I don't see what the problem is with your code, however, I would suggest using a Graphics object to draw the image instead of using Image object.
Here's an example:

Bitmap newImage = new Bitmap(newWidth, newHeight); using (Graphics gr = Graphics.FromImage(newImage)) {
    gr.SmoothingMode = SmoothingMode.AntiAlias;
    gr.InterpolationMode = InterpolationMode.HighQualityBicubic;
    gr.PixelOffsetMode = PixelOffsetMode.HighQuality;
    gr.DrawImage(srcImage, new Rectangle(0, 0, newWidth, newHeight)); }

Answer 2

ListView control (and ImageList too) is designed to work with uniform sized images. This can be weird, but this is the situation. So I let ListView work as it wants. I created SquareThumbnail from all of my images from the normal thumbnails:

private void Thumbnail_Square()
{
    Size size = new Size(Settings.Thumbnail.Size, Settings.Thumbnail.Size);
    this._squareThumbnail = new Bitmap(size.Width, size.Height, this._thumbnail.PixelFormat);
    Graphics g = Graphics.FromImage(this._squareThumbnail);
    g.FillRectangle(Brushes.Purple, 0, 0, size.Width, size.Height);
    size = this._thumbnail.Size;
    Point location = new Point(
        (Settings.Thumbnail.Size - size.Width) / 2,
        (Settings.Thumbnail.Size - size.Height) / 2);
    g.DrawImage(this._thumbnail,
    new Rectangle(location.X, location.Y, size.Width, size.Height),
    new Rectangle(0, 0, this._thumbnail.Width, this._thumbnail.Height), GraphicsUnit.Pixel);
    g.Dispose();
}

I used ImageList.TransparentColor = Color.Purple in the form to make it look good.