Print Page - ImageHeight and ImageWidth duplicates not the same?

Title: ImageHeight and ImageWidth duplicates not the same?
Post by: Beholder3 on June 19, 2012, 01:43:49 PM

Loook ed at a Pentax K-5 DNG file and just realised this:

Quote---- ExifTool ----
ExifTool Version Number : 8.95
---- File ----
File Name : IMGP3854.DNG
---- EXIF ----

Subfile Type : Full-resolution Image
Image Width : 4992
Image Height : 3284
Subfile Type : Reduced-resolution image
Image Width : 4928
Image Height : 3264

20 pixels in height and 84 pixels in width are for what? Where?
Windows only shows the "reduced-resolution image" dimension as the one dimensions. ???

Title: Re: ImageHeight and ImageWidth duplicates not the same?
Post by: Phil Harvey on June 19, 2012, 01:47:05 PM

RAW files typically store information from all sensor pixels, but not all pixels are imaging pixels. Usually there is a mask which blackens a frame around the image. My guess is that this mask is 10 pixels on the top and bottom, and 42 pixels each side of the image.

- Phil

Title: Re: ImageHeight and ImageWidth duplicates not the same?
Post by: Beholder3 on June 19, 2012, 01:57:02 PM

Ah, yes that could be it. Maybe it also has something to do with the shake reduction needing extra pixels around the edges if it's tilted.

Title: Re: ImageHeight and ImageWidth duplicates not the same?
Post by: Phil Harvey on June 19, 2012, 02:06:37 PM

I don't think it could be for shake reduction -- the entire sensor moves to compensate for shake/rotation. No pixels are harmed in the process.

- Phil

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General => Metadata => Topic started by: Beholder3 on June 19, 2012, 01:43:49 PM