Quote:
Originally Posted by Dr. Dave 4u
Just for fun, any ideas as to what might change in the file or its metadata?
Now you have me curious !!!
Thanks
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The metadata section will contain codes. Some camera pics will have more information than others. And not always in the same order of information from camera to other different kind of camera. But they all contain information such as orientation information. That orientation information is typically coded as numbers ----- (in the relevant section of the metadata) ---- like '1' or '2' or '3' or '4' or even up to number '8'. I think that usually there are only four relevant values --- that represent 0 degree rotation (relative to the pre-defined UP direction), 90 degree, -90 degree and 180 degree (upside down).
Each one is a code. The number '1' (if that's what is seen in the metadata for the orientation) usually means row number zero of an image is at the TOP, and column number zero is on the LEFT. That tells us that when we display the image on any basic picture viewer, then it would just come out looking 'normal' to us.
But if the photographer had rotated the camera from the camera's pre-defined 'UP' position (ie. rotated counter-clockwise by the equivalent of 90 degree, or rotated clockwise by 90 degree, or even rotated 180 degree --- ie upside down ----- then the associated code will be in that metadata. So - as long as you know where those values are in the metadata ----- and as long as you have a meta-data editor ------ and as long as you know the full details of the orientation information.
For example ---- my Samsung phone has a 6, 1, 3, 8 code system. Altering the value (ie. changing the number with meta-data editors will alter the orientation information.
For my Samsung phone - a '6' would mean the image displayed using a basic viewer would come out left-rotated by 90 degrees. This is assuming that the right-hand-side long edge of the phone is the general photo-taking orientation - ie. right-side long edge facing upwards to the sky is 'general' direction (but we know that a lot of people hold the phone vertically, which is fine - but is not the 'general' reference direction). And a '1' would mean the image would be displayed unrotated - normal. A '3' would mean upside down image. And a '8' would mean the image displayed would appear right-rotated by 90 degrees. Knowing the orientation information allows us to use our own program (software) to graphically rotate an image to the 'normal' position, and then also update the orientation information (such as to change it to a '1'), and then re-save the image automatically to a new filename. The new image file would then always be displayed correctly with any basic image viewer.
Naturally - there can be other situations - where we point a camera up toward the sky or something. So I'll ignore that situation heheh. But I wouldn't be surprised if some phones will provide 3 dimension information along with the meta-data.
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