Author Topic: EXIF Weeding; removing useless tags and uninformative values  (Read 777 times)

BrianP

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EXIF Weeding; removing useless tags and uninformative values
« on: September 22, 2015, 03:42:38 PM »
Some tags you NEVER want to see. Others have some values of interest and some which are better filtered

The table below has 196 "noise" items that will never clutter reports again. My MOST_USED_EXIF_TABLE!

Ex: ColorTemperature:                      0.0
This can be caused by bad software destroying information and has no informative relevant to the image (and has zero probability on a Maxwell-Boltzmann distribution)

The table has a key and an optional value. A NULL value destroys the key on sight. A TRUE value will be matched against the EXIF value and if found will delete the key/val pair.  The values can be OR (|) delimited to match on any of them.

This is useful when you want to see some detail but not all of the arcane minutia.  Here is the difference between -a (most, all but worst) and -A (and the kitchen sink)

get.exif.pl -sA m:/tmp/br5/BPB_5439.NEF | gr.pl -v SCAL > BPB_5439.NEF.all.exf
get.exif.pl -sa m:/tmp/br5/BPB_5439.NEF | gr.pl -v SCAL > BPB_5439.NEF.most.exf
dif  BPB_5439.NEF.most.exf BPB_5439.NEF.all.exf

27 Unique lines from "BPB_5439.NEF.all.exf":
  013) CFAPattern                 =>  [Red,Green][Green,Blue]
  026) DigitalZoomRatio           =>  1                                                 << NO digital zoom on D800E; NEVER want  to see
  042) FileCreateDate             =>  2013-05-14 12:18:08
  043) FileExtension              =>  NEF
  047) FileSource                 =>  Digital Camera
  068) FocalLengthIn35mmFormat    =>  16 mm                            <<   35mmFormat dups NEVER have useful info
  075) HueAdjustment              =>  None
  088) Lens                       =>  16-35mm f/4
  094) LightSource                =>  Unknown
  096) Make                       =>  NIKON CORPORATION
  099) MaxApertureValue           =>  4.0
  101) Megapixels                 =>  12.2
  115) PlanarConfiguration        =>  Chunky
  124) ReferenceBlackWhite        =>  0 255 0 255 0 255
  126) RowsPerStrip               =>  2844
  128) ScaleFactor35efl           =>  1.0
  129) SceneCaptureType           =>  Standard
  130) SceneType                  =>  Directly photographed
  131) SensingMethod              =>  One-chip color area
  135) ShutterSpeed               =>  1/80                                   << GOOD info, but alias  for ExposureTime. Units are SECONDS so speed is wrong label, time is right
  136) StripByteCounts            =>  14660380
  137) StripOffsets               =>  1665216
  138) SubjectDistanceRange       =>  Unknown                                 << NO_IDEA is  better left unsaid
  140) SubSecDateTimeOriginal     =>  2011-05-15 14:47:41.74
  142) SubSecTimeDigitized        =>  74
  143) SubSecTimeOriginal         =>  74
  144) TIFF-EPStandardID          =>  1 0 0 0


select * from exif_junk order by 2 -> 196 rows
cid,  ckey,                                 cval
1,    AlreadyApplied,                       
2,    APP14Flags0,                         
3,    APP14Flags1,                         
4,    ApplicationRecordVersion,                                      <<  No_Idea what this is; don't need to overlook it
5,    AutoLateralCA,                       
6,    AutoWhiteVersion,                     
177,  BitsPerSample,                        8
192,  BlackClip,                            0.000000
7,    BlueHue,                              0
8,    BlueMatrixColumn,                     0.14919 0.06322 0.74457|0.14305 0.06
...