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Image Rotation

Discussion in 'HDR-FOX T2 Freeview Recorder' started by Jeremy, Dec 13, 2011.

  1. Jeremy

    Jeremy Member

    Hi folks,

    I'm connecting successfully to my NAS drive through the HDR-FOXT2 for streaming movies and displaying my photos on the TV. Whilst this works fine, the photo side of things seems to be a bit lacking, in that photos will not automatically rotate.

    As I'm sure you know if you load pictures from your camera on to a Windows PC using the software that came with the camera (which is what most of us do I think), that software will perform a 'soft-rotate' if necessary, i.e. you took the picture with the camera at 90° to the subject and your software rotates the picture based on the orientation flag in the EXIF data. The photo itself stays 'landscape' in Windows though. If I stream photos direct to my Sony Bravia TV, the renderer on the TV does automatically rotate, so it's certainly possible, in theory, for the FOXT2 to do it but there isn't even a setting for this or a manual 'rotate image function'.

    I'm trying to use the FOXT2 as my 'entertainment centre' and not have the need the need to switch back and forth between it and the TV, so it's disappointing that the image handling on the FOXT2 is so weak. Is anyone aware of a solution to this? I was hoping that this was the kind of the thing that could be addressed by the customised firmware (maybe a package), which I already use.

    Any thoughts on this appreciated. Thanks.
     
  2. grahamlthompson

    grahamlthompson Well-Known Member

    Rotate the image in a photo editor and re-save. Or if you have WIN 7 try right clicking on the jpg icon in explorer and choose the appropriate rotate option.
     
  3. Jeremy

    Jeremy Member

  4. grahamlthompson

    grahamlthompson Well-Known Member

     
  5. Black Hole

    Black Hole Felonius Gru

    Not a chance. As far as I know we don't have direct access to the video output, so we couldn't even import a competent image viewer. You have what the Humax does and that's that, sorry.

    However, I would be very careful what you trust to open your photos on a Windows PC - Windows Picture Viewer (I think it's called) resaves the image file if you rotate it on screen, and it takes a little time to do that so I don't trust that it has only updated the EXIF data. Neither does it keep a back-up of the original file, or offer to save to a different name! Not good news for a jpeg, and I have not got around to looking into it.

    Graham's suggestion to save a rotated version for display only is ok (but a lot of work) as long as the saved file is a new one and not over-writing the original.
     
  6. grahamlthompson

    grahamlthompson Well-Known Member

    The text disappeared when I posted so I had to edit it back in. This post has just done the same. Looks like a forum problem
     
  7. grahamlthompson

    grahamlthompson Well-Known Member

    Photos displayed at 1920 x 1080 are generally a fraction of the original resolution, provided you work on a copy you are not going to see any difference. You get by far the best on screen images by cropping to 16:9 and resizing to 1920 x 1080.
     
  8. Jeremy

    Jeremy Member

    I do have Win7 and rotating in Explorer is the simplest option. I've heard some say that doing so loses the EXIF data but as far as I can see that isn't the case.
     
  9. fenlander

    fenlander Active Member

    Many free editors (Irfanview, Faststone, to name but 2) offer "lossless jpeg rotation" which simply adjusts the orientation data in the image's EXIF. The ability to auto-rotate images in a viewer depends upon both the camera and the viewer software. I have Panasonic and Fuji cameras. Viewed with Faststone, portrait-oriented images from the Panasonic are always automatically rotated while those from the Fuji have to be adjusted manually.
     
  10. Jeremy

    Jeremy Member

    This doesn't help though. I already use Faststone, which auto-rotates. But this is not reflected in Windows which will still display the photo in landscape, and the FOXT2 is rendering from what it finds there. As I understand it, Windows (even Win 7) does not read the orientation tag.
     
  11. grahamlthompson

    grahamlthompson Well-Known Member

    With jpegs it's always best to work on copies of your original file, as already observed everytime you open one and resave you lose a little more data so the picture quality gradually declines. Starting with a say 12Mp image though and displaying it at 1920 x 1080 you would have to it a lot of times before you notice any difference.
     
  12. Black Hole

    Black Hole Felonius Gru

    I find IE starts playing up after a while (I rarely reboot, just keep my notebook on sleep) and then a reboot sorts everything out again.
     
  13. grahamlthompson

    grahamlthompson Well-Known Member

    7 It's only on this forum, no problems elsewhere. Reboot every morning Had to edit again
     
  14. fenlander

    fenlander Active Member

    What I'm saying is that auto-rotation is an extra that you can't rely on for all combinations of image/viewer. For reliable results, always perform a lossless rotation of portrait format through 90 degrees. The result will then be correct on all viewers/devices.
     
  15. Black Hole

    Black Hole Felonius Gru

    I have often wondered whether the jpeg algorithm permits a "transcoding" of the data so that the image is rotated without a decoding-recoding operation. I understand it is based on a cosine spacial compression, but I imagine the actual data is axis-sensitive.
     
  16. fenlander

    fenlander Active Member

    There is an EXIF 'orientation' tag that has 8 permissible values, top-left being the default. I'm assuming that some (recent) cameras set it, some (older ones) don't, and that equally some viewers read it and some don't. Re-setting the image's orientation should just be a matter of resetting the tag value. Anyway, that's my best guess - I don't see why any transcoding should be necessary for a simple 90-degree rotation.
     
  17. Black Hole

    Black Hole Felonius Gru

    Easy - if the viewer doesn't take the EXIF data into account when it decides how to display the image.
     
  18. fenlander

    fenlander Active Member

    I've never encountered a software viewer or editor that didn't display correctly after a lossless rotation. Haven't used enough hardware devices (TVs, PVRs) to form an opinion.