GifOptions.ColorResolution

GifOptions.ColorResolution property

Gets or sets the GIF color resolution.

public byte ColorResolution { get; set; }

Property Value

The color resolution.

Remarks

Color Resolution - Number of bits per primary color available to the original image, minus 1. This value represents the size of the entire palette from which the colors in the graphic were selected, not the number of colors actually used in the graphic. For example, if the value in this field is 3, then the palette of the original image had 4 bits per primary color available to create the image. This value should be set to indicate the richness of the original palette, even if not every color from the whole palette is available on the source machine.

Examples

This example shows how to save a BMP image to GIF format using various options.

[C#]

string dir = "c:\\temp\\";

using (Aspose.Imaging.Image bmpImage = new Aspose.Imaging.FileFormats.Bmp.BmpImage(1000, 1000))
{
    // Fill the entire image with the blue-yellow gradient.
    Aspose.Imaging.Brushes.LinearGradientBrush gradientBrush = new Aspose.Imaging.Brushes.LinearGradientBrush(
            new Aspose.Imaging.Point(0, 0),
            new Aspose.Imaging.Point(bmpImage.Width, bmpImage.Height),
            Aspose.Imaging.Color.Blue,
            Aspose.Imaging.Color.Yellow);

    Aspose.Imaging.Graphics graphics = new Aspose.Imaging.Graphics(bmpImage);
    graphics.FillRectangle(gradientBrush, bmpImage.Bounds);

    Aspose.Imaging.ImageOptions.GifOptions saveOptions = new Aspose.Imaging.ImageOptions.GifOptions();

    // The number of bits required to store a color, minus 1.
    saveOptions.ColorResolution = 7;

    // Palette correction means that whenever image is exported to GIF the source image colors will be analyzed
    // in order to build the best matching palette (in case image Palette does not exist or not specified in the options)
    saveOptions.DoPaletteCorrection = true;

    // Load a GIF image in a progressive way.
    // An interlaced GIF doesn't display its scanlines linearly from top to bottom, but instead reorders it
    // so the content of the GIF becomes clear even before it finishes loading.
    saveOptions.Interlaced = true;

    // Save as a lossless GIF.
    using (System.IO.Stream stream = System.IO.File.OpenWrite(dir + "output.gif"))
    {
        bmpImage.Save(stream, saveOptions);
        System.Console.WriteLine("The size of the lossless GIF: {0} bytes.", stream.Length);
    }

    // Set the maximum allowed pixel difference. If greater than zero, lossy compression will be used.
    // The recommended value for optimal lossy compression is 80. 30 is very light compression, 200 is heavy.
    saveOptions.MaxDiff = 80;

    // Save as a lossy GIF.
    using (System.IO.Stream stream = System.IO.File.OpenWrite(dir + "output.lossy.gif"))
    {
        bmpImage.Save(stream, saveOptions);
        System.Console.WriteLine("The size of the lossy GIF: {0} bytes.", stream.Length);
    }
}

//The output may look like this:
//The size of the lossless GIF: 212816 bytes.
//The size of the lossy GIF: 89726 bytes.

GifOptions.ColorResolution