BackgroundColor

PngImage.BackgroundColor property

Retrieves the background color of the image, if one is specified. This property is helpful for applications that need to identify and potentially manipulate the background color of an image.

public override Color BackgroundColor { get; set; }

Examples

The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn’t support alpha channel.

[C#]

Aspose.Imaging.ImageOptions.PngOptions createOptions = new Aspose.Imaging.ImageOptions.PngOptions();
createOptions.Source = new Aspose.Imaging.Sources.FileCreateSource("c:\\temp\\transparent.png", false);
createOptions.ColorType = Aspose.Imaging.FileFormats.Png.PngColorType.Truecolor;

// Create a TrueColor PNG image of 100x100 px.
using (Aspose.Imaging.Image image = Image.Create(createOptions, 100, 100))
{
    Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;
    Aspose.Imaging.Graphics gr = new Aspose.Imaging.Graphics(pngImage);

    // All red pixels will be considered as fully transparent.
    pngImage.TransparentColor = Aspose.Imaging.Color.Red;
    pngImage.HasTransparentColor = true;

    // All transparent pixels will have a background color.
    pngImage.BackgroundColor = Aspose.Imaging.Color.Green;
    pngImage.HasBackgroundColor = true;

    // Fill the entire image with white color.
    gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.White), pngImage.Bounds);

    // Fill the top-left quarter of the image with the transparent color.
    // This makes the top-left quarter colored in the background color.
    Rectangle rect = new Rectangle(0, 0, pngImage.Width / 2, pngImage.Height / 2);
    gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red), rect);

    pngImage.Save();
}

See Also

PngImage BitsPerPixel