PngImage.HasTransparentColor

PngImage.HasTransparentColor property

Provides a boolean value indicating whether the image contains a transparent color. This property is crucial for applications that need to handle transparency, allowing developers to determine whether additional processing is required to handle transparent regions in the image.

public override bool HasTransparentColor { 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.HasBackgroundColor PngImage.Height