Convert All to JPG in C#

Question

I have a function like the following:

    // Convert To JPG 
    // 
    public string AlltoJPG(FileInfo foo)
    {
        // Get file extension
        string fileExtension = foo.Extension;

        // Get file name without extenstion
        string fileName = foo.Name.Replace(foo.Extension, string.Empty) + ".jpg";

        /*------------------------------------------------------------------------*/

        /// <Check for PNG File Format>
        if (fileExtension == ".png" || fileExtension == ".PNG")
        {
            System.Drawing.Image img = System.Drawing.Image.FromFile(foo.FullName);

            // Assumes img is the PNG you are converting
            using (Bitmap b = new Bitmap(img.Width, img.Height))
            {
                using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(b))
                {
                    g.Clear(System.Drawing.Color.White);
                    g.DrawImageUnscaled(img, 0, 0);
                }

                // Save the image as a JPG
                b.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);
            }

        }

        /*------------------------------------------------------------------------*/

        /// <Check for GIF File Format>
        if (fileExtension == ".gif" || fileExtension == ".GIF")
        {
            System.Drawing.Image img = System.Drawing.Image.FromFile(foo.FullName);

            // Construct a bitmap from the image resource.
            Bitmap bmp1 = new Bitmap(img.Width, img.Height);

            // Save the image as a JPG
            bmp1.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);
        }

        /*------------------------------------------------------------------------*/

        /// <Check for BMP File Format>
        if (fileExtension == ".bmp" || fileExtension == ".BMP")
        {
            System.Drawing.Image img = System.Drawing.Image.FromFile(foo.FullName);

            // Construct a bitmap from the image resource.
            Bitmap bmp1 = new Bitmap(img.Width, img.Height);

            // Save the image as a JPG
            bmp1.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);
        }

        /*------------------------------------------------------------------------*/

        /// <Check for TIFF File Format>
        if (fileExtension == ".tiff" || fileExtension == ".TIFF")
        {
            System.Drawing.Image img = System.Drawing.Image.FromFile(foo.FullName);

            // Construct a bitmap from the image resource.
            Bitmap bmp1 = new Bitmap(img.Width, img.Height);

            // Save the image as a JPG
            bmp1.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);
        }

        /*------------------------------------------------------------------------*/
        fileName = foo.DirectoryName + "\\" + fileName;
        return fileName;
    }

I'm trying to convert bmp,png,gif,tiff file formats to jpg, but GDI+ as gives:

System.OutOfMemoryException was unhandled
Message=Bellek yetersiz.
Source=System.Drawing
StackTrace:
konum: System.Drawing.Image.FromFile(String filename, Boolean useEmbeddedColorManagement)
konum: System.Drawing.Image.FromFile(String filename)

So how can I avoid this and convert at least PNG and BMP files to JPG?

Here is a picture of the error:

enter image description here

Have a look here : http://stackoverflow.com/questions/1108607/out-of-memory-exception-on-system-drawing-image-fromfile — Raphaël Althaus, Jun 11 '12 at 13:42
That stack trace doesn't fit the code you've supplied... no such vairable `OriginalImage` in your code — Shai, Jun 11 '12 at 13:42
@RaphaëlAlthaus yea i checked it before.. Nothing wrong with the pictures its the GDI+ causing this trouble. — Berker Yüceer, Jun 11 '12 at 13:49
Well i just checked it again and seen there is no problem with JPG files but when it comes to PNG trouble begins. So i'm on the possibility of alpha area problem here. — Berker Yüceer, Jun 11 '12 at 14:21

score 3 · Accepted Answer · edited May 23 '17 at 11:48

I found the problem! It was caused by PNG alpha channel..

Thanks to max, link below solved my problem:

How to load Transparent PNG to Bitmap and ignore alpha channel

public static void SetAlpha(this Bitmap bmp, byte alpha)
{
    if(bmp == null) throw new ArgumentNullException("bmp");

    var data = bmp.LockBits(
        new Rectangle(0, 0, bmp.Width, bmp.Height),
        System.Drawing.Imaging.ImageLockMode.ReadWrite,
        System.Drawing.Imaging.PixelFormat.Format32bppArgb);

    var line = data.Scan0;
    var eof = line + data.Height * data.Stride;
    while(line != eof)
    {
        var pixelAlpha = line + 3;
        var eol = pixelAlpha + data.Width * 4;
        while(pixelAlpha != eol)
        {
            System.Runtime.InteropServices.Marshal.WriteByte(
                pixelAlpha, alpha);
            pixelAlpha += 4;
        }
        line += data.Stride;
    }
    bmp.UnlockBits(data);
}

Usage:

var pngImage = new Bitmap("filename.png");
pngImage.SetAlpha(255);

after setting alpha it started to work correctly.

score 0 · Answer 2 · answered Jun 11 '12 at 14:02

0

The gif, png, and tiff code blocks are missing using clauses and are leaking the GDI references.

answered Jun 11 '12 at 14:02

asawyer

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Convert All to JPG in C#

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