WPF的“Stretch.Uniform”等图像填充逻辑答案

【问题标题】：Image FILL logic such as "Stretch.Uniform" of WPFWPF的“Stretch.Uniform”等图像填充逻辑
【发布时间】：2019-09-28 07:18:54
【问题描述】：

我正在寻找要在我的控制台应用程序中应用的图像填充逻辑，它会生成 TIFF 文件。我的图像容器尺寸为 1200 * 1800 像素。

已应用以下逻辑来调整图像大小以适应此尺寸，但此逻辑应用 FIT 部分而不是 FILL 部分。

如果我的图像尺寸为 1200 * 1600，那么我会在下面得到空白区域，如果我尝试将图像放入容器中，那么它会拉伸图像并且图像看起来不太好. 1200 * 1600 上面的图片非常适合。

我正在寻找类似于 WPF 应用程序的“Stretch.Uniform”的逻辑，它可以均匀地填充图像而不会丢失图像的实际视图。

private static Dimension getScaledDimension(Dimension imgSize, Dimension boundary)
{

    int original_width = imgSize.width;
    int original_height = imgSize.height;
    int bound_width = boundary.width;
    int bound_height = boundary.height;
    int new_width = original_width;
    int new_height = original_height;

    // first check if we need to scale width. 
    if (original_width > bound_width)  
    {
        //scale width to fit
        new_width = bound_width;
        //scale height to maintain aspect ratio
        new_height = (new_width * original_height) / original_width;
    }


    // then check if we need to scale even with the new height. 
    if (new_height > bound_height)
    {
        //scale height to fit instead
        new_height = bound_height;
        //scale width to maintain aspect ratio
        new_width = (new_height * original_width) / original_height;
    }

    return new Dimension { height = new_height, width = new_width };
}

【问题讨论】：

标签： c# wpf image-scaling

【解决方案1】：

检查 2 个矩形的纵横比以决定适合哪个属性。

private static Dimension getScaledDimension(Dimension imgSize, Dimension boundary)
{
    int original_width = imgSize.width;
    int original_height = imgSize.height;
    int bound_width = boundary.width;
    int bound_height = boundary.height;

    double original_aspect = (double)original_width / original_height;
    double bound_aspect = (double)bound_width / bound_height;

    //original size is wider than boundary, fit boundary width
    if(original_aspect > bound_aspect)
    {
        return new Dimension
        {
            width = boundary.width,
            height = (int)Math.Round(boundary.width / original_aspect)
        };
    }

    //original size is taller than boundary, fit boundary height
    else
    {
        return new Dimension
        {
            height = boundary.height,
            width = (int)Math.Round(boundary.height * original_aspect)
        };
    }
}

【讨论】：