CODEWITHSUNDEEP
c#image-processing
Yanshof
Yanshof

Reputation: 9926

How to compress jpg image?

I have jpg image format with size of 3300K.

I try to compress the image => so i changed the image size but still i have very big size of the file ( ~ 800K )

The change size method code:

    internal static Image resizeImage( Image imgToResize )
    {
        Bitmap b = new Bitmap( 300, 300 );

        using( Graphics g = Graphics.FromImage( ( Image )b ) )
        {
            //g.InterpolationMode = InterpolationMode.HighQualityBicubic;
            g.InterpolationMode = InterpolationMode.Low;

            g.DrawImage( imgToResize, 0, 0, 300, 300 );

            imgToResize.Dispose();
        }

        return ( Image )b;
    }

I must compress the image - even if the quality of the image will be less then the original.

How can i do it ?

Upvotes: 4

Views: 14552

Answers (2)

sikender
sikender

Reputation: 5921

mg = image

newsize = height and width

Call Resize function using following code

Bitmap mg = new Bitmap(strUploadPath);
Size newSize = new Size(Convert.ToInt32(DispMaxWidth), Convert.ToInt32(DispMaxHeight));
Bitmap bp = ResizeImage(mg, newSize);
if (bp != null)
bp.Save(strUploadPath, System.Drawing.Imaging.ImageFormat.Jpeg);

private Bitmap ResizeImage(Bitmap mg, Size newSize)
        {
            double ratio = 0d;
            double myThumbWidth = 0d;
            double myThumbHeight = 0d;
            int x = 0;
            int y = 0;

            Bitmap bp;

            if ((mg.Width / Convert.ToDouble(newSize.Width)) > (mg.Height /
            Convert.ToDouble(newSize.Height)))
                ratio = Convert.ToDouble(mg.Width) / Convert.ToDouble(newSize.Width);
            else
                ratio = Convert.ToDouble(mg.Height) / Convert.ToDouble(newSize.Height);
            myThumbHeight = Math.Ceiling(mg.Height / ratio);
            myThumbWidth = Math.Ceiling(mg.Width / ratio);

            //Size thumbSize = new Size((int)myThumbWidth, (int)myThumbHeight);
            Size thumbSize = new Size((int)newSize.Width, (int)newSize.Height);
            bp = new Bitmap(newSize.Width, newSize.Height);
            x = (newSize.Width - thumbSize.Width) / 2;
            y = (newSize.Height - thumbSize.Height);
            // Had to add System.Drawing class in front of Graphics ---
            System.Drawing.Graphics g = Graphics.FromImage(bp);
            g.SmoothingMode = SmoothingMode.HighQuality;
            g.InterpolationMode = InterpolationMode.HighQualityBicubic;
            g.PixelOffsetMode = PixelOffsetMode.HighQuality;
            Rectangle rect = new Rectangle(x, y, thumbSize.Width, thumbSize.Height);
            g.DrawImage(mg, rect, 0, 0, mg.Width, mg.Height, GraphicsUnit.Pixel);

            return bp;

        }

Upvotes: 10

Grzegorz Gierlik
Grzegorz Gierlik

Reputation: 11232

JPG images are already compressed.

You can try to decrease size of image using different algorithm of compression of decrease quality of image.

In this case try to set of CompositingQuality or SmoothingMode properties to better (for you) values -- maybe there are others properties which can help.

Upvotes: 2

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