PremultiplyComponents

RasterImage.PremultiplyComponents property

获取或设置一个值，该值指示是否必须对图像分量进行预乘。

public virtual bool PremultiplyComponents { get; set; }

适当的价值

真的如果必须对图像分量进行预乘；否则，错误的 .

例子

下面的示例创建一个新的光栅图像，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.PngOptions createOptions = new Aspose.Imaging.ImageOptions.PngOptions();
createOptions.Source = new Aspose.Imaging.Sources.StreamSource(new System.IO.MemoryStream(), true);
createOptions.ColorType = Aspose.Imaging.FileFormats.Png.PngColorType.TruecolorWithAlpha;

using (Aspose.Imaging.Image image = Aspose.Imaging.Image.Create(createOptions, imageWidth, imageHeight))
{
    Aspose.Imaging.RasterImage rasterImage = (Aspose.Imaging.RasterImage)image;

    // 保存整个图像的像素。
    rasterImage.SavePixels(rasterImage.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;
    rasterImage.PremultiplyComponents = true;
    Aspose.Imaging.Color[] premultipliedColors = rasterImage.LoadPixels(rasterImage.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());
    }
}

也可以看看

IsRawDataAvailable RawCustomColorConverter