怎样通过C#获取图片（tif)的压缩方式，

怎样通过C#获取图片（tif)的压缩方式，

比如：有一张图片

图片路径：d:\test.tif
图片的压缩：CCITT 4
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现在我想同过代码来获取该图片的“压缩方式”，

问题一：请问怎样获取呢？

问题二：请问我对图片进行处理（比如：旋转）之后，再保存该图片的时候，怎样才能不改变该图片的压缩方式（CCITT 4）呢？

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希望各位帮帮忙，指点下，我感激不尽。

            // 问题一：
            // 获取TIFF编码解码器
            ImageCodecInfo ImageCodecInfo1 = null;
            ImageCodecInfo[] encoders = ImageCodecInfo.GetImageDecoders();
            foreach (ImageCodecInfo imageCodecInfo in encoders)
            {
                if (imageCodecInfo.FormatDescription=="TIFF")
                {
                    ImageCodecInfo1 = imageCodecInfo;
                    break;
                }
            }
            // 读取图片
            Image image1 = Image.FromFile(@"c:\1.tif");
            EncoderParameters eps = image1.GetEncoderParameterList(ImageCodecInfo1.Clsid);
            foreach (EncoderParameter ep in eps.Param)
            {
                // 查找压缩参数(注意要ToString)
                if (ep.Encoder.ToString() == System.Drawing.Imaging.Encoder.Compression.ToString())
                {
                    //用枚举System.Drawing.Imaging.EncoderValue与compressionValue比对
                    int compressionValue = ep.NumberOfValues;
                    int v2 = (int)System.Drawing.Imaging.EncoderValue.CompressionLZW;
                    int v3 = (int)System.Drawing.Imaging.EncoderValue.CompressionCCITT3;
                    int v4 = (int)System.Drawing.Imaging.EncoderValue.CompressionCCITT4;
                    int v5 = (int)System.Drawing.Imaging.EncoderValue.CompressionRle;
                    int v6 = (int)System.Drawing.Imaging.EncoderValue.CompressionNone;
                }
            }