C# 仿照photoshop 亮度调节

在C#中，如果你想要创建一个类似于Photoshop中的亮度调节功能，你可以利用.NET Framework中的System.Drawing命名空间，特别是Image类及其派生类。这里是一个简单的示例，展示如何调整图像的亮度：

using System.Drawing;
using System.Drawing.Imaging;

public class ImageBrightnessModifier {
    public static Bitmap AdjustBrightness(Bitmap sourceImage, float brightnessFactor) {
        if (sourceImage == null) throw new ArgumentNullException(nameof(sourceImage));

        // 创建一个新的Bitmap，用于保存处理后的图像
        Bitmap result = new Bitmap(sourceImage.Width, sourceImage.Height);

        // 使用锁像素的方式进行操作，防止并发修改
        using (Graphics graphics = Graphics.FromImage(result)) {
            // 设置绘图上下文的模式
            graphics.CompositingMode = CompositingMode.SourceCopy;
            graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
            graphics.DrawImage(sourceImage, 0, 0, result.Width, result.Height);

            // 获取图像的数据
            ColorMatrix colorMatrix = new ColorMatrix(
                new float[,]
                {
                    {brightnessFactor, 0, 0, 0, 0},
                    {0, brightnessFactor, 0, 0, 0},
                    {0, 0, brightnessFactor, 0, 0},
                    {0, 0, 0, 1, 0},
                    {0, 0, 0, 0, 1} // Alpha通道保持不变
                });

            // 应用矩阵变换
            ImageAttributes attributes = new ImageAttributes();
            attributes.SetColorMatrix(colorMatrix);
            graphics.DrawImage(sourceImage, new Rectangle(0, 0, result.Width, result.Height), 0, 0, result.Width, result.Height, GraphicsUnit.Pixel, attributes);
        }

        return result;
    }
}

// 调用示例
Bitmap originalImage = ...; // 加载图片
float brightnessLevel = 1.5f; // 调整范围从-1到1，正值增加亮度，负值降低亮度
Bitmap brightenedImage = ImageBrightnessModifier.AdjustBrightness(originalImage, brightnessLevel);