Upside down images in some software?

[Merlin66]

Has anyone noticed that different software can present the same image upside down?

I was comparing a screen dump from PHD and AstroArtV5 and just realised the images, from the same camera, same set-up were 180 degree different.

[Scott]

Must refrain from some half baked joke pertaining to antipodeans . I get it all the time at work. 

I must say I've not noticed it but you've got me wondering if theres a "image correction" (for want of a better name) button in the menu somewhere? I must remember to have a look next time out 

[Merlin66]

;-)

I asked on the PHD group, and the answer given was that different software has a different way of presenting images - no standards.

[andrew s]

Yes Ken, I find it a real pain. Some put (0,0) at top left and others bottom left.

Regards Andrew

[JamesF]

Yes Ken, I find it a real pain. Some put (0,0) at top left and others bottom left.

Regards Andrew

Indeed.  My recollection is that FITS assumes the origin to be at the top left of the image.  I think TIFF might, too.  People generally want to work with the origin at the bottom left though, so it's bound to lead to confusion.  I know it makes it a pig of a job when you want to turn a YUYV frame into a FITS file

I'd guess it's because memory has historically tended to map to a display from top left to bottom right as one would read a book so it's handy for some applications to lay the image out that way.  In turn that's presumably because CRTs scan that way.  Perhaps CRTs scan that way because books are read that way (for some of us, at least).  I imagine it would have been no more difficult to start scanning at the bottom left and move up the screen rather than down.

James

[nytecam]

Hi Ken - I've been aware for a decade AA presents an inverted image but as long as you know it's not a problem and easily sorted

[Merlin66]

Yeah,

Under normal circumstances it's a non event....

It's only when you compare images.

Do other imaging programs show the same?

[Gina]

I get this with DSS and invert the images in Photoshop - a minor inconvenience but an inconvenience nevertheless