i simply want to load a .BMP file and get the Bitmap object in 24bit RGB format (or 32bit in RGB format).
All methods I tried return a Bitmap/Image object with PixelFormat = Format32bppArgb. Even if of course BMPs don't have alpha.
new Bitmap(System.Drawing.Image.FromFile(fileName, true));
new Bitmap(fileName);
I currently solve the problem by copying the first object to another in memory bitmap at 24bit RBG.
Is there a single method to do it?
Thanks
As far as I can tell it is not possible to specify the PixelFormat for loading bitmaps using the classes in System.Drawing. To convert the bitmap check this question: Converting Bitmap PixelFormats in C#
This is currently the top answer there:
Bitmap orig = new Bitmap(@"c:\temp\24bpp.bmp");
Bitmap clone = new Bitmap(orig.Width, orig.Height, System.Drawing.Imaging.PixelFormat.Format32bppPArgb);
using (Graphics gr = Graphics.FromImage(clone)) {
gr.DrawImage(orig, new Rectangle(0, 0, clone.Width, clone.Height));
}
// Dispose orig as necessary..
One option would be to put that in a function which takes a filename and PixelFormat. That hides the ugly code, which has its ups and downs since it also hides the fact it is probably not that efficient.
According to the linked SO question using the Clone method not always works.
You can clone it to a RGB format one:
var bitmapInRgbFormat = loadedBitmap.Clone(new Rectangle(0, 0, loadedBitmap.Width, loadedBitmap.Height), PixelFormat.Format32bppRgb)
Exactly what do you mean by copying the first object to another?
To achieve what you want to do, meaning loading an image and converting it to 24 bit, just get the graphics context of a second bitmap that matches the size and that is RGB, and paint the original bitmap onto this one.
