csharp C＃将图像转换为jpeg

Posted 2021-05-12

        ImageCodecInfo jpgEncoder = imageHelper.GetEncoder(ImageFormat.Jpeg);
        
        // define a target quality/fiedlity
        System.Drawing.Imaging.Encoder myEncoder = System.Drawing.Imaging.Encoder.Quality;
        EncoderParameters myEncoderParameters = new EncoderParameters(1);
        EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, 80L);
        myEncoderParameters.Param[0] = myEncoderParameter;

        var ms = new MemoryStream(imgData); // imgData would come from db in this example
        System.Drawing.Image image = System.Drawing.Image.FromStream(ms);
        image.Save(filePath1, jpgEncoder, myEncoderParameters);
        
        public ImageCodecInfo GetEncoder(ImageFormat format)
        {
            ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();
            foreach (ImageCodecInfo codec in codecs)
            {
                if (codec.FormatID == format.Guid)
                {
                    return codec;
                }
            }
            return null;
        }