List view control displaying distorted images

I have a problem with the ListView control in a windows forms application. Even if I create a thumbnail image or resize the real one I get distorted images in the list view. The image looks like when you zoom in an image very much. I first thought that the GetThumbnailImage is couseing this but I used a resize code I found here and I have the same result.

I also did not found any bug related to list view control so I gues I'm doing something wrong but I just can't figure out what. Here is the code I use:

lsvPictures.LargeImageList = m_imagesList;
lsvPictures.LargeImageList.ImageSize = new Size(100, 100);
lsvPictures.View = View.LargeIcon;
lsvPictures.CheckBoxes = true;
for (int i = 0; i < ofd.FileNames.Length; i++)
{
    filename = ofd.FileNames[i].ToString();    
    ListViewItem lvi = new ListViewItem(filename);
    m_imagesList.Images.Add(ResizeImage(Image.FromFile(filename), 100, 100));
    lvi.ImageIndex = i;
    lsvPictures.Items.Add(lvi);
} 

And this is the function that resizes images:

public static System.Drawing.Bitmap ResizeImage(System.Drawing.Image image, 
                                                int width, int height)
{        
    //a holder for the result
    Bitmap result = new Bitmap(width, height);

    //use a graphics object to draw the resized image into the bitmap
    using (Graphics graphics = Graphics.FromImage(result))
    {
        //set the resize quality modes to high quality
        graphics.CompositingQuality = 
            System.Drawing.Drawing2D.CompositingQuality.HighQuality;
        graphics.InterpolationMode =
            System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        graphics.SmoothingMode = 
            System.Drawing.Drawing2D.SmoothingMode.HighQuality;
        //draw the image into the target bitmap
        graphics.DrawImage(image, 0, 0, result.Width, result.Height);
    }
    //return the resulting bitmap
    return result;
}

Thank you! Mosu'

I just found the source of the problems:

m_imagesList.ColorDepth = ColorDepth.Depth16Bit;

It seams that, as de开发者_开发百科fault, the ColorDepth of the ImageList is 8 bit (or 4 bit, but my guess is 8). If I change this to at least 16 bit everything looks very nice.

To those with similar problems: I changed my Thumbnail method a lot before I realised that the ListView control is not using the color depth the images were having. I put the result of my method on a PictureBox control and saw that the function was working corectly. Atfer this I googled a lot ... and found that silly ColorDepth property.

How did you set the resolution for your image. Also, did what did you set the PixelFormat value to when you created the bitmap? I have a list of images loading into my list view that I am resizing similar to how you are and it is working fine without any distortion in the resulting thumbnail images that are created.

Here is a snippet from my resize method.

Bitmap bitmap = new Bitmap(width, height, PixelFormat.Format24bppRgb);
        bitmap.SetResolution(image.HorizontalResolution, image.VerticalResolution);
        using (Graphics graphics = Graphics.FromImage(bitmap))
        {
            graphics.Clear(Color.Red);
            graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
            graphics.DrawImage(image,
                new Rectangle(destinationX, destinationY, destinationWidth, destinationHeight),
                new Rectangle(sourceX, sourceY, originalWidth, originalHeight),
                GraphicsUnit.Pixel);
        }
        return bitmap;

I was also using a ListView in WinForms to display directories, and had the same problem. I suggest that you check the image file type: icon files (.ico) tend to end up distorted, so try to use an image file with the .png extension. This works for me:

ListView listView = new ListView();
ImageList imageList = new ImageList();
// add image to list:
imageList.Images.Add("image_key", image_path);
// give the listview the imagelist:
listView.SmallImageList = imageList;
// add item to listview:
listView.Items.Add("item_text", "image_key");