Strange bmp black output from BitmapSource - any ideas?

Question

I have a byte[] array with the bgra bytes of an image, from which I produce a BitmapSource like so:

BitmapSource bmsOut = BitmapSource.Create(
iPixelWidth, iPixelHeight, 96, 96, PixelFormats.Bgra32, null, bytOutput, iStride);

this displays fine on an wpf Image element. HOWEVER, when I then try to create a file from the BitmapSource:

private void mtdSave(BitmapSource bitmapSource, string path, BitmapEncoder encoder)
          {
              using (var stream = new FileStream(path, FileMode.Create))
              {
                  encoder.Frames.Add(BitmapFrame.Create(bitmapSource));
                  encoder.Save(stream);
              }
          }

I get strange output dependent on the encoder used: bmp gives a little, maybe 10x10 pixel image of the centre of the image in a sea of black, png does the same without the black. The displayed area looks as if the picture has been cropped by a thumbnail outline (just to describe the visula effect) Furthermore, if you then open the png in Paint the whole picture is there and displayed, but not for the bmp version (Irfanview cannot cope with either of the files)

What is going on? What am I missing?

I tried to add pictures, but as a new user your spam filter will not let me — The English Patient, Jan 16 '12 at 15:52
You can still post a link (I think) or even add one in the comments and someone will edit it into the question for you. — ChrisF, Jan 16 '12 at 15:59

score 1 · Answer 1 · answered Jan 16 '12 at 15:18

1

What kind of BitmapEncoder are you passing in? Did you try a PngBitmapEncoder?

answered Jan 16 '12 at 15:18

MyKuLLSKI

5,285
3
20
39

Yes, I use the PngBitmapEncoder for png and the BmpBitmapEncoder for bmp - I just checked again. – The English Patient Jan 16 '12 at 15:57
think you can post a reproduction of your project? – MyKuLLSKI Jan 16 '12 at 15:58
1

PngBitmapEncoder and saving it as a .png file instead of .bmp made my black image become normal :DDDDDD – Sep 19 '12 at 15:11

Strange bmp black output from BitmapSource - any ideas?

1 Answers1

Linked