View Full Version : Y800 Memory Layout

August 11, 2008, 23:18:28

Forgive me if I am in the wrong forum, but none look quite right for my question. I am attempting to interface our data acquisition system to ImageSource cameras (currently the DMK 21AU04.AS). I am doing this directly via the DirectShow interface - not via any of the ImagingSource SDKs.

Everything works fine except that the image is inverted. The BITMAPINFOHEADER I get for the DMK camera has a positive biHeight parameter which usually implies an origin in the lower left corner (see http://msdn.microsoft.com/en-us/library/ms532290(VS.85).aspx for interpretation of biHeight). Usually for origins in the upper left, the biHeight parameter is negative.

Is this intentional? I have looked around on the web for Y800 to see if there is some implicit orientation but I do not see one.

Indeed one of the few articles I found was on this very forum: "Y800 grayscale bitmap not compatible?" where they are also noting an inverted image in some applications. I would assume those applications are making the same interpretation I am.

Can anyone shine any light on this?

Best regards,

Tom Udale

Sascha Schmidt
August 15, 2008, 13:15:51
Hallo Tom,

Please have a look at "www.fourcc.org" under "RGB formats" -> "Bitmap Orientation and biHeight" and "YUV formats" -> Y800. Maybe this helps.