1.0.3 • Public • Published


Convert RAW camera images using JavaScript (supported on Node.js and your Browser)

This project is a port of dcraw.c using Emscripten.



npm install dcraw


<script src="https://cdn.jsdelivr.net/npm/dcraw"></script>


Read a RAW image file into a buffer (or Uint8Array in the browser, see browser example here)

const fs = require('fs');
const buf = fs.readFileSync('./example.CR2');
Get Image Metadata

Parse the file for metadata

const dcraw = require('dcraw');
dcraw(buf, { verbose: true, identify: true });


>   Filename: raw_buf
    Timestamp: Thu Sep 21 07:17:42 2017
    Camera: Canon EOS 20D
    Owner: unknown
    ISO speed: 3200
    Shutter: 252.0 sec
    Aperture: f/inf
    Focal length: 0.0 mm
    Embedded ICC profile: no
    Number of raw images: 1
    Thumb size:  1536 x 1024
    Full size:   3596 x 2360
    Image size:  3522 x 2348
    Output size: 3522 x 2348
    Raw colors: 3
    Filter pattern: RG/GB
    Daylight multipliers: 2.098645 0.930145 1.180146
    Camera multipliers: 1021.000000 1015.000000 1018.000000 1015.000000
Convert to TIFF

Convert to TIFF file, and save to disk

const tiffFile = dcraw(buf, { exportAsTiff: true });
fs.writeFileSync('example.tiff', tiffFile)


You may use the same options that dcraw supports by providing the flags directly, or you may use the following human friendly versions.

// The following dcraw command, can be written two ways using dcraw.js
// dcraw -T -4 -E <filename>
// Both of these do the same thing
dcraw(buf, { T: true, 4: true, E: true });
dcraw(buf, { exportAsTiff: true, use16BitLinearMode: true, useExportMode: true });
Options List
Option Type Description
verbose boolean Print verbose messages
identify boolean Identify files without decoding them (use with '-v' to identify files and show metadata)
extractThumbnail boolean Extract embedded thumbnail image
useCameraWhiteBalance boolean Use camera white balance, if possible
useAverageWhiteBalance boolean Average the whole image for white balance
whiteBalanceBox x y w h Average a grey box for white balance
useCustomWhiteBalance r g b g Set custom white balance
useEmbeddedColorMatrix boolean Use/don't use an embedded color matrix
correctChromaticAberration r b Correct chromatic aberration
deadPixelFile buffer Fix the dead pixels listed in this file
darkFrameFile buffer Subtract dark frame (16-bit raw PGM)
setDarknessLevel num Set the darkness level
setSaturationLevel num Set the saturation level
setWaveletThreshold num Set threshold for wavelet denoising
setHighlightMode [0-9] Highlight mode (0=clip, 1=unclip, 2=blend, 3+=rebuild)
setFlipMode [0-7] Flip image (0=none, 3=180, 5=90CCW, 6=90CW)
setColorSpace [0-6] Output colorspace (raw,sRGB,Adobe,Wide,ProPhoto,XYZ,ACES)
setICCFromFile buffer Apply output ICC profile from file
setICCFromCamera buffer Apply camera ICC profile from file or "embed"
useDocumentMode boolean Document mode (no color, no interpolation, no debayer)
useRawMode boolean Document mode without scaling (totally raw)
useExportMode boolean Document mode without cropping
setNoStretchMode boolean Don't stretch or rotate raw pixels
setNoAutoBrightnessMode boolean Don't automatically brighten the image
setBrightnessLevel num Adjust brightness (default = 1.0)
setCustomGammaCurve p ts Set custom gamma curve (default = 2.222 4.5)
setInterpolationQuality [0-3] Set the interpolation quality
setHalfSizeMode boolean Half-size color image (twice as fast as "-q 0")
setFourColorMode boolean Interpolate RGGB as four colors
setMedianFilter num Apply a 3x3 median filter to R-G and B-G
setImageCount [0..N-1] Select one raw image or "all" from each file
use16BitMode boolean Write 16-bit instead of 8-bit
use16BitLinearMode boolean Linear 16-bit, same as "-6 -W -g 1 1"
exportAsTiff boolean Write TIFF instead of PPM

Browser Example

You'll need to do a little bit of work to get a file buffer on the browser. There is a full example available here.

var reader = new FileReader();
reader.onload = function (e) {
    // Get the image file as a buffer
    var buf = new Uint8Array(e.currentTarget.result);
    // Get the RAW metadata
    const metadata = dcraw(buf, { verbose: true, identify: true });



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