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How to convert DNG without normalization?
Posted: 2015-12-28T11:46:52-07:00
by Meloware
I am using my Canon DSLR to capture 16mm movie film. My camera creates raw DNG format images. Any conversion I try (such as mogrify -format png somefile.DNG) results in a normalized image, rather than one with the original brightness, contrast, and whitebalance values. This default behaviour isn't any good for creating movie frame sequences.
Is imagemagick using dcraw to convert these files? The dcraw command, dcraw -6 -T -W somefile.DNG, gives me the conversion I wish.
Is there some way to produce the same result in an imagemagick command line?
I have tens of thousands of images to batch process. Of course, there are other transformations to still do within imagemagick, and it is important to avoid wasting time and saving huge intermediate files. Movie film preservation needs your help!
Re: How to convert DNG without normalization?
Posted: 2015-12-28T12:51:10-07:00
by fmw42
mogrify -format png somefile.DNG
Try
Code: Select all
mogrify -format png DNG:somefile.DNG
From
http://www.imagemagick.org/script/formats.php
DNG R Digital Negative Requires an explicit image format otherwise the image is interpreted as a TIFF image (e.g.
dng:image.dng).
IM does use dcraw to process RAW files.
I am unaware of any special -defines for DNG images to customize processing.
Re: How to convert DNG without normalization?
Posted: 2015-12-28T14:35:57-07:00
by magick
ImageMagick uses the
dcraw-batch delegate program under Linux and
dcraw under Windows to read DNG files. The
dcraw-batch delegate program provides additional camera metadata. For example,
Code: Select all
-> identify -verbose CRW_0049.dng
identify -verbose CRW_0049.dng
Image: /tmp/magick-1540923BfiksRl3Co.png
Base filename: CRW_0049.dng
Format: DNG (Digital Negative)
Class: DirectClass
Geometry: 2630x1970+0+0
Units: Undefined
Type: TrueColor
Endianess: Undefined
Colorspace: sRGB
Depth: 16-bit
Channel depth:
red: 16-bit
green: 16-bit
blue: 16-bit
Channel statistics:
Pixels: 5181100
Red:
min: 0 (0)
max: 65535 (1)
mean: 32295.8 (0.492802)
standard deviation: 22256.2 (0.339607)
kurtosis: -1.35923
skewness: 0.366125
entropy: 0.788557
Green:
min: 0 (0)
max: 65535 (1)
mean: 32805.3 (0.500577)
standard deviation: 21932.5 (0.334669)
kurtosis: -1.34468
skewness: 0.380011
entropy: 0.82547
Blue:
min: 0 (0)
max: 65535 (1)
mean: 32271.9 (0.492437)
standard deviation: 22156.4 (0.338085)
kurtosis: -1.31337
skewness: 0.487454
entropy: 0.781009
Image statistics:
Overall:
min: 0 (0)
max: 65535 (1)
mean: 32457.7 (0.495272)
standard deviation: 22115.4 (0.33746)
kurtosis: -1.33952
skewness: 0.410946
entropy: 0.798345
Rendering intent: Perceptual
Gamma: 0.454545
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 2630x1970+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: TopLeft
Properties:
date:create: 2015-12-28T16:26:57-05:00
date:modify: 2015-12-28T16:26:57-05:00
dng:Aperture: F2.8
dng:AspectRatio: 1.335025
dng:ChannelMultipliers: 1.677888 1.000000 1.311410 1.000000
dng:CreateID: 1
dng:Crop: 0 0 2630 1970
dng:EXIFSource: exiv2 0.25
dng:FocalLength: 7.1 mm
dng:Green: 1.353
dng:ISOSpeed: 50
dng:Make: Canon
dng:MatrixInputProfile: Color matrix
dng:Model: PowerShot S50
dng:Orientation: 0
dng:Rotation: 0.000000
dng:Shutter: 1/1000 s
dng:sRGBOutputProfile: sRGB
dng:Temperature: 5407
dng:Timestamp: Fri Jun 3 13:23:50 2005
dng:WB: Auto WB
dng:WBFineTuning: 0
exif:ApertureValue: 2970854/1000000
exif:ColorSpace: 1
exif:DateTimeOriginal: 2005:06:03 13:23:50
exif:ExifOffset: 594
exif:ExposureBiasValue: 0/1
exif:ExposureProgram: 3
exif:ExposureTime: 1/1000
exif:Flash: 0
exif:FNumber: 28/10
exif:FocalLength: 71/10
exif:ISOSpeedRatings: 50
exif:Make: Canon
exif:MaxApertureValue: 309375/100000
exif:MeteringMode: 2
exif:Model: Canon PowerShot S50
exif:Orientation: 1
exif:ShutterSpeedValue: 9965784/1000000
png:IHDR.bit-depth-orig: 16
png:IHDR.bit_depth: 16
png:IHDR.color-type-orig: 2
png:IHDR.color_type: 2 (Truecolor)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 2630, 1970
png:sRGB: intent=0 (Perceptual Intent)
png:text: 3 tEXt/zTXt/iTXt chunks were found
png:text-encoded profiles: 1 were found
signature: 429021c94b1e544d06ea90840e35562c54f57cf9ad736a970b6bc73fa4ffc8d9
Software: UFRaw
Source: CanonPowerShot S50
unknown: UFRaw 0.21
Profiles:
Profile-exif: 838 bytes
Artifacts:
filename: CRW_0049.dng
verbose: true
Tainted: False
Filesize: 21.67MB
Number pixels: 5.181M
Pixels per second: 126.37GB
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.9.3-0 Q16 x86_64 2016-01-07 http://www.imagemagick.org
Re: How to convert DNG without normalization?
Posted: 2015-12-28T14:39:55-07:00
by Meloware
Try
Code: Select all
mogrify -format png DNG:somefile.DNG
Thank you for the reply, but this suggestion doesn't affect my problem. The contrast still gets normalized. This prevents me from being able to control any levels across an entire image sequence. A 'fade to black', becomes a dissolve to noisy grey. Light vs dark scenes cannot be reproduced.
Is there anything else I might try? Is it possible to write a script which first uses the dcraw command, and then pass the result as an object which imagemagick may finish processing? A 30Mb dng turns into a 100Mb tiff. Saving each intermediate frame to disk will quickly eat a 4Tb drive and require a ton of additional CPU time. Unfortunately, I am stuck with Windows 7, so that may be even more limiting.
Re: How to convert DNG without normalization?
Posted: 2015-12-28T16:09:21-07:00
by magick
Locate the delegates.xml file on your system. You can edit the parameters we pass to the dcraw program to get the desired results.
Re: How to convert DNG without normalization?
Posted: 2015-12-28T16:32:33-07:00
by Meloware
Bingo! Thank You
My problem was solved by editing 'delegates.xml'. I replaced your dng decode command option from '-w' to '-W', and I was done.