How can I convert a BMP to JPEG without saving to file?

Question

I have a BMP image object which contains a BMP image, how can I convert it to JPEG format without saving to file?

All I need to know is the size of the JPEG file after the conversion, so If I have several BMP images, I want to convert each one of them into a JPEG and then see the size of each one.

How can I do that?

Thanks.

Save it to a MemoryStream. – Dan Byström Mar 14 '19 at 12:03 — Dan Byström, Mar 14 '19 at 12:03

score 2 · Answer 1 · answered Mar 14 '19 at 12:12

Just save it stream. and look size.

private ImageCodecInfo GetEncoder(ImageFormat format)
    {

        ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();

        foreach (ImageCodecInfo codec in codecs)
        {
            if (codec.FormatID == format.Guid)
            {
                return codec;
            }
        }
        return null;
    }

    private void Form1_Load(object sender, EventArgs e)
    {

        Bitmap bmp1 = new Bitmap(@"C:\Users\ercan.acar\Pictures\Current CR Sticker.PNG");
        ImageCodecInfo jpgEncoder = GetEncoder(ImageFormat.Jpeg);

        System.Drawing.Imaging.Encoder myEncoder =System.Drawing.Imaging.Encoder.Quality;

        EncoderParameters myEncoderParameters = new EncoderParameters(1);

        EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder,
            50L);
        myEncoderParameters.Param[0] = myEncoderParameter;
        Stream stream=new MemoryStream();
        bmp1.Save(stream, jpgEncoder,myEncoderParameters);
        //bmp1.Save(@"C:\Users\ercan.acar\Documents\TestPhotoQualityFifty.jpg",);

        var size = stream.Length;

    }

score 0 · Answer 2 · answered Mar 14 '19 at 12:17

0

How about using a nuget package like Magick.NET or similar. Why reinventing the wheel and care about encoding, conversion adjustments, optimization if other have done this already for you.

answered Mar 14 '19 at 12:17

TiTime

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How can I convert a BMP to JPEG without saving to file?

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