GIF to JPEG over white

[bmjnine]

Hi all,

I am converting image files of various formats to JPEG using:

System.Drawing. Image img = System.Drawing. Image.FromFile( myfilepath);

Works great except that transparent GIF's are over a black background
instead of white. What would be the simplest way to convert GIF's to an
Image object over a white background?

I have tried the following:

System.Drawing. Image img = new Bitmap(myfilepa th);
Bitmap bmp = new Bitmap(img.Widt h, img.Height);
Graphics gfc = Graphics.FromIm age(bmp);
gfc.Clear(Color .White);
gfc.DrawImage(i mg, 0, 0);
img = bmp;

This does work for the GIF's over white, but then sometimes when a JPEG
runs through this code, it gets resized, so I'm not convinced this is
the best route.

Thanks in advance,
Alyssa

[Marcin Grzêbski]

Hi,

bm*****@hotmail .com napisa³(a):

Hi all,

I am converting image files of various formats to JPEG using:

System.Drawing. Image img = System.Drawing. Image.FromFile( myfilepath);

Works great except that transparent GIF's are over a black background
instead of white. What would be the simplest way to convert GIF's to an
Image object over a white background?

I have tried the following:

I recommend these changes in your code:

System.Drawing. Image img = new Bitmap(myfilepa th);
PixelFormat pixFormat=img.P ixelFormat;
if( pixFormat==Pixe lFormat.Format8 bppIndexed
|| Image.IsAlphaPi xelFormat(pixFo rmat) ) {
Bitmap bmp = new Bitmap(img.Widt h, img.Height);
using( Graphics gfc = Graphics.FromIm age(bmp) ) {
gfc.Clear(Color .White);
gfc.DrawImageUn scaled(img, 0, 0);
}
Image oldImg=img;
img = bmp;
oldImg.Dispose( );
}

This does work for the GIF's over white, but then sometimes when a JPEG
runs through this code, it gets resized, so I'm not convinced this is
the best route.

These changes can assure you that there's no way to draw JPEG
till it has no alpha channel.

Cheers! & HTH
Marcin