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DVD Cover H/W ratio
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DVD Profiler Unlimited Registrantjfrench
Registered: April 16, 2008
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I've been working on reports recently and not wanting to distort images I checked the height to width ratio of a cover and noticed that it was equal to 1.414, the square root of 2.  Can anyone see any reason for this?
DVD Profiler Desktop and Mobile Registrantmediadogg
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Registered: March 18, 2007
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Quoting jfrench:
Quote:
I've been working on reports recently and not wanting to distort images I checked the height to width ratio of a cover and noticed that it was equal to 1.414, the square root of 2.  Can anyone see any reason for this?

Seems odd that they would all be exactly that. When I looked at the image folder of one of my databases, the ratio was indeed in the vicinity of 1.4, but not all exactly 1.414. Perhaps a coincidence of the one you looked at?
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 Last edited: by mediadogg
DVD Profiler Desktop and Mobile RegistrantStar ContributorAiAustria
Registered: May 19, 2007
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Maybe something about the German paper format?

...
Din A5 = 210x148,5mm
Din A4 = 297x210mm
Din A3 = 420x297mm
...

The ratio is the square root of two, because the area of a sheet is doubled from one format to the next larger one...
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 Last edited: by AiAustria
DVD Profiler Unlimited Registrantjfrench
Registered: April 16, 2008
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I felt pretty good about the height of the cover being 182 mm and less sure about the width, but estimated it as 129 mm.  128.7 mm results in a closer approximation but  the 1.41 rang a bell.
I see that the Din paper size ratio is the square root of two and that the area doubles with each size increase but trying to figure the math for that escapes me.  It does seem likely that it's not simply coincidental that the Din and DVD cover ratios are the same.
DVD Profiler Desktop and Mobile Registrantmediadogg
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Correction Din A5 = 210mm x 148mm. See here.

The math is simple: By definition, cut an A0 in half to get A1, cut an A1 in half to get A2, and so on. (Edited - better picture here showing proper proportions.).

Final edit: If you set up an equation for the ratio of Long side to short side, and require that each time you cut the page in half, that the ratio of long side to short side remains constant, the only ratio that works is square root of 2.
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 Last edited: by mediadogg
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