PremultiplyComponents

TiffImage.PremultiplyComponents property

获取或设置一个值，该值指示是否必须对分量进行预乘。

public override bool PremultiplyComponents { get; set; }

适当的价值

真的如果组件必须预乘；否则，错误的 .

例子

下面的示例创建一个新的 TIFF 图像，保存指定的半透明像素，然后加载这些像素并以预乘形式获取最终颜色。

[C#]

int imageWidth = 3;
int imageHeight = 2;

Aspose.Imaging.Color[] colors = new Aspose.Imaging.Color[]
{
    Aspose.Imaging.Color.FromArgb(127, 255, 0, 0),
    Aspose.Imaging.Color.FromArgb(127, 0, 255, 0),
    Aspose.Imaging.Color.FromArgb(127, 0, 0, 255),
    Aspose.Imaging.Color.FromArgb(127, 255, 255, 0),
    Aspose.Imaging.Color.FromArgb(127, 255, 0, 255),
    Aspose.Imaging.Color.FromArgb(127, 0, 255, 255),
};

Aspose.Imaging.ImageOptions.TiffOptions createOptions = new Aspose.Imaging.ImageOptions.TiffOptions(Aspose.Imaging.FileFormats.Tiff.Enums.TiffExpectedFormat.TiffDeflateRgba);
createOptions.Source = new Aspose.Imaging.Sources.StreamSource(new System.IO.MemoryStream(), true);

using (Aspose.Imaging.FileFormats.Tiff.TiffImage image = (Aspose.Imaging.FileFormats.Tiff.TiffImage)Aspose.Imaging.Image.Create(createOptions, imageWidth, imageHeight))
{
    // 保存整个图像的像素。
    image.SavePixels(image.Bounds, colors);

    // 像素以非预乘的形式存储在原始图像中。
    // 需要显式指定相应的选项才能获得预乘的颜色分量。
    // 预乘的颜色分量由以下公式计算：
    // 红色 = original_red * alpha / 255;
    // 绿色 = original_green * alpha / 255;
    // 蓝色 = original_blue * alpha / 255;
    image.PremultiplyComponents = true;
    Aspose.Imaging.Color[] premultipliedColors = image.LoadPixels(image.Bounds);

    for (int i = 0; i < colors.Length; i++)
    {
        System.Console.WriteLine("Original color: {0}", colors[i].ToString());
        System.Console.WriteLine("Premultiplied color: {0}", premultipliedColors[i].ToString());
    }
}

//输出将如下所示：
//原色：Color [A=127, R=255, G=0, B=0]
//预乘颜色：Color [A=127, R=127, G=0, B=0]
//原色：Color [A=127, R=0, G=255, B=0]
//预乘颜色：Color [A=127, R=0, G=127, B=0]
//原色：Color [A=127, R=0, G=0, B=255]
//预乘颜色：Color [A=127, R=0, G=0, B=127]
//原色：Color [A=127, R=255, G=255, B=0]
//预乘颜色：Color [A=127, R=127, G=127, B=0]
//原色：Color [A=127, R=255, G=0, B=255]
//预乘颜色：Color [A=127, R=127, G=0, B=127]
//原色：Color [A=127, R=0, G=255, B=255]
//预乘颜色：Color [A=127, R=0, G=127, B=127]

也可以看看

Pages VerticalResolution