3

I love using View NX2 to import, organize and edit my pictures from my Nikon D3200 camera. What I do not love is converting images with it. It can be quite slow when converting and can take overnight to convert 30 pictures. I do not have the best computer in the world, so sometimes I like to outsource tasks to my VPS and let it handle all the tough jobs my computer can't handle. Since I know converting images can be a tough job, I would like my VPS to handle this while still be able to convert a quick image from my Windows computer.

I am looking for software that can convert .NEF (RAW) pictures to .JPG with no or very little loss in quality that has support for both Linux (command line) and Windows.

Requirements:

  • Must have support for both Linux (CentOS) and Windows (7)
  • Must be able to "batch convert" the images (IE I don't want to convert one file at a time. On Linux, this should recursively select all the files in a folder and convert them to a specified output folder)
  • Must convert with little or no loss in quality
  • Must output to .JPG or .JPEG
  • Must be gratis (free)
  • Shouldn't use too much processing and RAM power but I know this can be hard to find when dealing with images so its not a set requirement, but it would be nice to have

3 Answers 3

3

Imagemagick can read NEF files to output jpeg or a wide range of other formats.

  • Free/Gratis
  • Cross platform
  • Command Line conversion
  • Batch conversion
  • Lots of input & output formats:
~$ identify -list
format     Format  Module    Mode  Description
-------------------------------------------------------------------------------
  3FR  DNG       r--   Hasselblad CFV/H3D39II
    A* RAW       rw+   Raw alpha samples
  AAI* AAI       rw+   AAI Dune image
   AI  PDF       rw-   Adobe Illustrator CS2
  ART* ART       rw-   PFS: 1st Publisher Clip Art
  ARW  DNG       r--   Sony Alpha Raw Image Format
  AVI  MPEG      r--   Microsoft Audio/Visual Interleaved
  AVS* AVS       rw+   AVS X image
    B* RAW       rw+   Raw blue samples
  BGR* BGR       rw+   Raw blue, green, and red samples
 BGRA* BGR       rw+   Raw blue, green, red, and alpha samples
  BIE* JBIG      rw-   Joint Bi-level Image experts Group interchange format (2.0)
  BMP* BMP       rw-   Microsoft Windows bitmap image
 BMP2* BMP       -w-   Microsoft Windows bitmap image (V2)
 BMP3* BMP       -w-   Microsoft Windows bitmap image (V3)
  BRF* BRAILLE   -w-   BRF ASCII Braille format
    C* RAW       rw+   Raw cyan samples
  CAL* CALS      rw-   Continuous Acquisition and Life-cycle Support Type 1
       Specified in MIL-R-28002 and MIL-PRF-28002
 CALS* CALS      rw-   Continuous Acquisition and Life-cycle Support Type 1
       Specified in MIL-R-28002 and MIL-PRF-28002
CANVAS* XC        r--   Constant image uniform color
CAPTION* CAPTION   r--   Caption
  CIN* CIN       rw-   Cineon Image File
  CIP* CIP       -w-   Cisco IP phone image format
 CLIP* CLIP      -w+   Image Clip Mask
 CMYK* CMYK      rw+   Raw cyan, magenta, yellow, and black samples
CMYKA* CMYK      rw+   Raw cyan, magenta, yellow, black, and alpha samples
  CR2  DNG       r--   Canon Digital Camera Raw Image Format
  CRW  DNG       r--   Canon Digital Camera Raw Image Format
  CUR* CUR       rw-   Microsoft icon
  CUT* CUT       r--   DR Halo
  DCM* DCM       r--   Digital Imaging and Communications in Medicine image
       DICOM is used by the medical community for images like X-rays.  The
       specification, "Digital Imaging and Communications in Medicine
       (DICOM)", is available at http://medical.nema.org/.  In particular,
       see part 5 which describes the image encoding (RLE, JPEG, JPEG-LS),
       and supplement 61 which adds JPEG-2000 encoding.
  DCR  DNG       r--   Kodak Digital Camera Raw Image File
  DCX* PCX       rw+   ZSoft IBM PC multi-page Paintbrush
  DDS* DDS       r--   Microsoft DirectDraw Surface
DFONT* TTF       r--   Multi-face font package (Freetype 2.5.2)
 DJVU* DJVU      r--   D�j� vu
       See http://www.djvuzone.org/ for details about the DJVU format.  The
       DJVU 1.2 specification is available there and at
       ftp://swrinde.nde.swri.edu/pub/djvu/documents/.
  DNG  DNG       r--   Digital Negative
  DOT  DOT       ---   Graphviz
  DPX* DPX       rw-   SMPTE 268M-2003 (DPX 2.0)
       Digital Moving Picture Exchange Bitmap, Version 2.0.
       See SMPTE 268M-2003 specification at http://www.smtpe.org
       
 EPDF  PDF       rw-   Encapsulated Portable Document Format
  EPI  PS        rw-   Encapsulated PostScript Interchange format
  EPS  PS        rw-   Encapsulated PostScript
 EPS2* PS2       -w-   Level II Encapsulated PostScript
 EPS3* PS3       -w+   Level III Encapsulated PostScript
 EPSF  PS        rw-   Encapsulated PostScript
 EPSI  PS        rw-   Encapsulated PostScript Interchange format
  EPT  EPT       rw-   Encapsulated PostScript with TIFF preview
 EPT2  EPT       rw-   Encapsulated PostScript Level II with TIFF preview
 EPT3  EPT       rw+   Encapsulated PostScript Level III with TIFF preview
  ERF  DNG       r--   Epson RAW Format
  EXR  EXR       rw-   High Dynamic-range (HDR)
  FAX* FAX       rw+   Group 3 FAX
       FAX machines use non-square pixels which are 1.5 times wider than
       they are tall but computer displays use square pixels, therefore
       FAX images may appear to be narrow unless they are explicitly
       resized using a geometry of "150x100%".
       
 FITS* FITS      rw-   Flexible Image Transport System
FRACTAL* PLASMA    r--   Plasma fractal image
  FTS* FTS       rw-   Flexible Image Transport System
    G* RAW       rw+   Raw green samples
   G3* FAX       rw-   Group 3 FAX
  GIF* GIF       rw+   CompuServe graphics interchange format
GIF87* GIF       rw-   CompuServe graphics interchange format (version 87a)
GRADIENT* GRADIENT  r--   Gradual linear passing from one shade to another
 GRAY* GRAY      rw+   Raw gray samples
GROUP4* TIFF      rw-   Raw CCITT Group4
 HALD*           r--   Identity Hald color lookup table image
  HDR* HDR       rw+   Radiance RGBE image format
HISTOGRAM* HISTOGRAM -w-   Histogram of the image
  HRZ* HRZ       rw-   Slow Scan TeleVision
  HTM* HTML      -w-   Hypertext Markup Language and a client-side image map
 HTML* HTML      -w-   Hypertext Markup Language and a client-side image map
  ICB* TGA       rw-   Truevision Targa image
  ICO* ICON      rw+   Microsoft icon
 ICON* ICON      rw-   Microsoft icon
 INFO  INFO      -w+   The image format and characteristics
INLINE* INLINE    r--   Base64-encoded inline images
  IPL* IPL       rw+   IPL Image Sequence
ISOBRL* BRAILLE   -w-   ISO/TR 11548-1 format
  J2C* JP2       rw-   JPEG-2000 Code Stream Syntax
  J2K* JP2       rw-   JPEG-2000 Code Stream Syntax
  JBG* JBIG      rw+   Joint Bi-level Image experts Group interchange format (2.0)
 JBIG* JBIG      rw+   Joint Bi-level Image experts Group interchange format (2.0)
  JNG* PNG       rw-   JPEG Network Graphics
       See http://www.libpng.org/pub/mng/ for details about the JNG
       format.
  JP2* JP2       rw-   JPEG-2000 File Format Syntax
  JPC* JP2       rw-   JPEG-2000 Code Stream Syntax
 JPEG* JPEG      rw-   Joint Photographic Experts Group JFIF format (80)
  JPG* JPEG      rw-   Joint Photographic Experts Group JFIF format (80)
  JPX* JP2       rw-   JPEG-2000 File Format Syntax
    K* RAW       rw+   Raw black samples
  K25  DNG       r--   Kodak Digital Camera Raw Image Format
  KDC  DNG       r--   Kodak Digital Camera Raw Image Format
LABEL* LABEL     r--   Image label
    M* RAW       rw+   Raw magenta samples
  M2V  MPEG      rw+   MPEG Video Stream
  M4V  MPEG      rw+   Raw MPEG-4 Video
  MAC* MAC       r--   MAC Paint
  MAP* MAP       rw-   Colormap intensities and indices
  MAT  MAT       rw+   MATLAB level 5 image format
MATTE* MATTE     -w+   MATTE format
  MEF  DNG       r--   Mamiya Raw Image File
 MIFF* MIFF      rw+   Magick Image File Format
  MNG* PNG       rw+   Multiple-image Network Graphics (libpng 1.2.50)
       See http://www.libpng.org/pub/mng/ for details about the MNG
       format.
 MONO* MONO      rw-   Raw bi-level bitmap
  MOV  MPEG      rw+   MPEG Video Stream
  MP4  MPEG      rw+   MPEG-4 Video Stream
  MPC* MPC       rw+   Magick Persistent Cache image format
 MPEG  MPEG      rw+   MPEG Video Stream
  MPG  MPEG      rw+   MPEG Video Stream
  MRW  DNG       r--   Sony (Minolta) Raw Image File
  MSL* MSL       rw+   Magick Scripting Language
 MSVG  SVG       rw+   ImageMagick's own SVG internal renderer
  MTV* MTV       rw+   MTV Raytracing image format
  MVG* MVG       rw-   Magick Vector Graphics
  NEF  DNG       r--   Nikon Digital SLR Camera Raw Image File
  NRW  DNG       r--   Nikon Digital SLR Camera Raw Image File
 NULL* NULL      rw-   Constant image of uniform color
    O* RAW       rw+   Raw opacity samples
  ORF  DNG       r--   Olympus Digital Camera Raw Image File
  OTB* OTB       rw-   On-the-air bitmap
  OTF* TTF       r--   Open Type font (Freetype 2.5.2)
  PAL* UYVY      rw-   16bit/pixel interleaved YUV
 PALM* PALM      rw+   Palm pixmap
  PAM* PNM       rw+   Common 2-dimensional bitmap format
PANGO* PANGO     r--   Pango Markup Language (Pangocairo 1.36.1)   
PATTERN* PATTERN   r--   Predefined pattern
  PBM* PNM       rw+   Portable bitmap format (black and white)
  PCD* PCD       rw-   Photo CD
 PCDS* PCD       rw-   Photo CD
  PCL  PCL       rw+   Printer Control Language
  PCT* PICT      rw-   Apple Macintosh QuickDraw/PICT
  PCX* PCX       rw-   ZSoft IBM PC Paintbrush
  PDB* PDB       rw+   Palm Database ImageViewer Format
  PDF  PDF       rw+   Portable Document Format
 PDFA  PDF       rw+   Portable Document Archive Format
  PEF  DNG       r--   Pentax Electronic File
  PES* PES       r--   Embrid Embroidery Format
  PFA* TTF       r--   Postscript Type 1 font (ASCII) (Freetype 2.5.2)
  PFB* TTF       r--   Postscript Type 1 font (binary) (Freetype 2.5.2)
  PFM* PFM       rw+   Portable float format
  PGM* PNM       rw+   Portable graymap format (gray scale)
  PGX* JP2       r--   JPEG-2000 VM Format
PICON* XPM       rw-   Personal Icon
 PICT* PICT      rw-   Apple Macintosh QuickDraw/PICT
  PIX* PIX       r--   Alias/Wavefront RLE image format
PJPEG* JPEG      rw-   Joint Photographic Experts Group JFIF format (80)
PLASMA* PLASMA    r--   Plasma fractal image
  PNG* PNG       rw-   Portable Network Graphics (libpng 1.2.50)
       See http://www.libpng.org/ for details about the PNG format.
PNG24* PNG       rw-   opaque 24-bit RGB (zlib 1.2.8)
PNG32* PNG       rw-   opaque or transparent 32-bit RGBA
 PNG8* PNG       rw-   8-bit indexed with optional binary transparency
  PNM* PNM       rw+   Portable anymap
  PPM* PNM       rw+   Portable pixmap format (color)
 PREVIEW* PREVIEW   -w-   Show a preview an image enhancement, effect, or f/x
   PS  PS        rw+   PostScript
  PS2* PS2       -w+   Level II PostScript
  PS3* PS3       -w+   Level III PostScript
  PSB* PSD       rw+   Adobe Large Document Format
  PSD* PSD       rw+   Adobe Photoshop bitmap
 PTIF* TIFF      rw+   Pyramid encoded TIFF
  PWP* PWP       r--   Seattle Film Works
    R* RAW       rw+   Raw red samples
RADIAL-GRADIENT* GRADIENT  r--   Gradual radial passing from one shade to another
  RAF  DNG       r--   Fuji CCD-RAW Graphic File
  RAS* SUN       rw+   SUN Rasterfile
  RGB* RGB       rw+   Raw red, green, and blue samples
 RGBA* RGB       rw+   Raw red, green, blue, and alpha samples
 RGBO* RGB       rw+   Raw red, green, blue, and opacity samples
  RLA* RLA       r--   Alias/Wavefront image
  RLE* RLE       r--   Utah Run length encoded image
  SCR* SCR       r--   ZX-Spectrum SCREEN$
  SCT* SCT       r--   Scitex HandShake
  SFW* SFW       r--   Seattle Film Works
  SGI* SGI       rw+   Irix RGB image
SHTML* HTML      -w-   Hypertext Markup Language and a client-side image map
  SR2  DNG       r--   Sony Raw Format 2
  SRF  DNG       r--   Sony Raw Format
STEGANO* STEGANO   r--   Steganographic image
  SUN* SUN       rw+   SUN Rasterfile
  SVG  SVG       rw+   Scalable Vector Graphics (RSVG 2.40.1)
 SVGZ  SVG       rw+   Compressed Scalable Vector Graphics (RSVG 2.40.1)
 TEXT* TXT       rw+   Text
  TGA* TGA       rw-   Truevision Targa image
THUMBNAIL* THUMBNAIL -w+   EXIF Profile Thumbnail
 TIFF* TIFF      rw+   Tagged Image File Format (LIBTIFF, Version 4.0.3)
TIFF64* TIFF      rw-   Tagged Image File Format (64-bit) (LIBTIFF, Version 4.0.3)
 TILE* TILE      r--   Tile image with a texture
  TIM* TIM       r--   PSX TIM
  TTC* TTF       r--   TrueType font collection (Freetype 2.5.2)
  TTF* TTF       r--   TrueType font (Freetype 2.5.2)
  TXT* TXT       rw+   Text
 UBRL* BRAILLE   -w-   Unicode Text format
  UIL* UIL       -w-   X-Motif UIL table
 UYVY* UYVY      rw-   16bit/pixel interleaved YUV
  VDA* TGA       rw-   Truevision Targa image
VICAR* VICAR     rw-   VICAR rasterfile format
  VID* VID       rw+   Visual Image Directory
 VIFF* VIFF      rw+   Khoros Visualization image
  VST* TGA       rw-   Truevision Targa image
 WBMP* WBMP      rw-   Wireless Bitmap (level 0) image
  WMF* WMF       r--   Windows Meta File
  WMV  MPEG      rw+   Windows Media Video
  WMZ* WMZ       r--   Compressed Windows Meta File
  WPG* WPG       r--   Word Perfect Graphics
    X* X         rw+   X Image
  X3F  DNG       r--   Sigma Camera RAW Picture File
  XBM* XBM       rw-   X Windows system bitmap (black and white)
   XC* XC        r--   Constant image uniform color
  XCF* XCF       r--   GIMP image
  XPM* XPM       rw-   X Windows system pixmap (color)
  XPS  XPS       r--   Microsoft XML Paper Specification
   XV* VIFF      rw+   Khoros Visualization image
  XWD* XWD       rw-   X Windows system window dump (color)
    Y* RAW       rw+   Raw yellow samples
YCbCr* YCbCr     rw+   Raw Y, Cb, and Cr samples
YCbCrA* YCbCr     rw+   Raw Y, Cb, Cr, and alpha samples
   YUV* YUV       rw-   CCIR 601 4:1:1 or 4:2:2

* native blob support
r read support
w write support
+ support for multiple images
2

Pretty much all free / open-source RAW converters, including all the other recommendations given so far (ImageMagick and Darktable), are based on the dcraw command-line tool by Dave Coffin.

Dcraw can do pretty much anything that commercial RAW decoders can, at least up to the limits of the developers' ability to reverse engineer the various proprietary RAW formats that camera vendors keep coming up with. In fact, it's what ImageMagick (as recommended by Steve Barnes) uses internally to decode RAW files.

If you're just looking to quickly batch-decode a bunch of NEF files, and have some familiarity with the Unix command line, you could just use the dcraw command-line interface directly. Alas, the one thing it doesn't do is write out JPEG files, but you can always pipe the PPM output from dcraw into cjpeg or ImageMagick to convert it to JPEG.

However, if you want to adjust things like exposure and white balance in your photos while decoding them, you'll most likely want to use a GUI front-end like UFRaw, Darktable or RawTherapee. All of these are cross-platform tools, so they should run on both Windows and Linux.

Since you say you're mostly interested in batch converting multiple photos at a time, I'd also recommend the Rawstudio front-end, which is designed primarily for this purpose. However, it does not currently seem to have a Windows port, so it'd only be a solution on Linux.

3
  • At first I did find dcraw when I was doing my initial searching but I found it to be a little bit inconvenient to convert twice. Still great app though. I'll be editing all that stuff before hand (which is why its in RAW in the first place and not in JPEG from the camera) so mainly my main problem is converting. I'll probably be using the command line for simplicity, make a simple script to do it automatically. Very detailed answer! Thanks for that!
    – aman207
    Commented Jul 21, 2014 at 3:35
  • Note that there are some adjustments (such as, notably, exposure correction) that you really want to do before converting to JPEG, because JPEG only supports 8-bit color, and so loses much of the dynamic range of your RAW photos. (If you have an image editor that supports 16-bit TIFF or some HDR image format like EXR, you could convert the images to those without dynamic range loss; but at that point, it's probably easier to keep them in NEF format, or possibly in DNG if you don't like NEF for some reason.) Commented Jul 21, 2014 at 8:45
  • Yeah that's what I plan on doing. Literally the only reason I need to convert them is to print them off at my local photo lab.
    – aman207
    Commented Jul 22, 2014 at 3:05
0

You may want to look at online NEF converter at Raw.pics.io. It is different from other online converters in a way that it performs everything on the client-side. It should work for you both on Linux and Windows.

1
  • Are you associated with that software? If so, you should disclose that in your answer.
    – vclaw
    Commented May 9, 2015 at 21:41

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