On Wed, 2008-04-09 at 13:43 +0300, Petri Helin wrote:
On Wed, Apr 9, 2008 at 9:43 AM, Jouni Karvo Jouni.Karvo@iki.fi wrote:
Nevertheless, although probably most techies feel the crop mode is not interesting, perhaps you'll be able to find one that is willing to implement it - or perhaps you can DIY and share the code.
I think the idea of cropping material from aspect ratios 16:9 or 2.39:1 to 4:3 is not worth putting attention, because it will often result in quite awkward image. When done properly with technique called pan&scan (http://en.wikipedia.org/wiki/Pan_and_scan) where the cropped selection can reside at any part of the original image, the result is bearable. But think about a movie shot and broadcasted in 2.39 and crudely cropped so that the 4:3 part in the middle is shown... You will see half heads, people talking to people not included in the picture and so on. Or think about a football match in 16:9 cropped to 4:3... with the ball in the portion left out.
However, often things just work out: the camera operators are sometimes directed to shoot the full 16:9 frame but keep the action in a 4:3 frame. This does happen, and IMHO makes for shots that seem too wide on a 16:9 screen. Production companies do this to maximise the market potential for their material. To use the football case: the international feeds still need to deliver 4:3 images. So the host broadcaster who wants both a 16:9 version and a 4:3 version can either employ twice as many camera operators and have twice as many cameras etc etc OR shoot 16:9 but keep the action in the 4:3 frame.
Then there is 14:9 material. This is shown on a 4:3 image with smaller black bars, or cropped less (than 16:9) and shown full screen on a 4:3.
(I myself prefer the black bars on top and on bottom and view all 16:9 programmes that way on my 4:3 set)
(For movies the transfer to video can take more time: there pan&scan is used, but so are other techniques including letterbox, image distortion etc. It is particularly noticeable at the end of a movie with credits that use the whole 16:9 width)
-Petri
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