NEF image size is wrong and extra parameters are invalid

[llanc]

Describe the bug
When converting NEF (NIKON ELECTRIC FILM) format, the resulting webp loses its original pixel ratio. The QUALITY parameter and extra parameters is invalid. Not sure if other RAW formats are ok.

To Reproduce
Just use a NEF image.

Expected behavior
NEF images or other RAW images can work fine.

Screenshots and logs
webp


NEF

Environment (please complete the following information):

• OS: debian 11
• version or branchd: docker latest

Additional context
none

[n0vad3v]

From our docs:

Currently supported image format: JPEG, PNG, BMP, GIF, SVG, HEIC

NEF format is currently NOT supported, and the problem seems libwebp related, I've tried using cwebp like:

cwebp DSC_0001.NEF -o output.webp
TIFFReadDirectory: Warning, Unknown field with tag 36867 (0x9003) encountered.
TIFFReadDirectory: Warning, Unknown field with tag 37398 (0x9216) encountered.
Saving file 'output.webp'
File:      DSC_0001.NEF
Dimension: 160 x 120
Output:    4310 bytes Y-U-V-All-PSNR 37.27 38.71 39.62   37.81 dB
           (1.80 bpp)
block count:  intra4:         64  (80.00%)
              intra16:        16  (20.00%)
              skipped:         6  (7.50%)
bytes used:  header:            142  (3.3%)
             mode-partition:    335  (7.8%)
 Residuals bytes  |segment 1|segment 2|segment 3|segment 4|  total
    macroblocks:  |      20%|      21%|      38%|      21%|      80
      quantizer:  |      36 |      30 |      22 |      16 |
   filter level:  |      11 |       7 |       4 |       2 |

du -ch DSC_0001.NEF
12M	DSC_0001.NEF
12M	total

du -ch output.webp 
8.0K	output.webp
8.0K	total

This gives similar results from what you've posted.

[llanc]

How about converting NEF (RAW) images to JPG first and then to WEBP?

[n0vad3v]

How about converting NEF (RAW) images to JPG first and then to WEBP?

No, it's not that easy, NEF images are little bit hard to deal with, for example, if you use file to check for a NEF image, you'll find it has no standard dimension data:

file 1.NEF 
1.NEF: TIFF image data, big-endian, direntries=25, height=0, bps=0, compression=none, PhotometricInterpretation=RGB, manufacturer=NIKON CORPORATION, model=NIKON XXXXX, orientation=upper-left, width=0

Note height=0 and width=0

So currently we suggest you to convert those NEF images to JPEG or some other supported image formats before using WebP Server Go to render them.

BTW, I've tried https://github.com/rwcarlsen/goexif for extracting info from the above NEF image, and has incorrect results:

package main

import (
	"fmt"
	"os"

	"github.com/rwcarlsen/goexif/exif"
	"github.com/rwcarlsen/goexif/mknote"
)

func main() {

	nefFile, err := os.Open("1.NEF")
	if err != nil {
		fmt.Println(err)
	}
	defer nefFile.Close()
	exif.RegisterParsers(mknote.All...)

	exifData, err := exif.Decode(nefFile)
	if err != nil {
		fmt.Println(err)
	}

	camModel, _ := exifData.Get(exif.Model) // normally, don't ignore errors!
	fmt.Println(camModel.StringVal())

	XResolution, _ := exifData.Get(exif.XResolution)
	YResolution, _ := exifData.Get(exif.YResolution)
	ResolutionUnit, _ := exifData.Get(exif.ResolutionUnit)
	PixelXDimension, _ := exifData.Get(exif.PixelXDimension)
	PixelYDmension, _ := exifData.Get(exif.PixelYDimension)
	ImageWidth, _ := exifData.Get(exif.ImageWidth)
	ImageLength, _ := exifData.Get(exif.ImageLength)

	fmt.Println(XResolution)
	fmt.Println(YResolution)
	fmt.Println(ResolutionUnit)
	fmt.Println(PixelXDimension)
	fmt.Println(PixelYDmension)
	fmt.Println(ImageWidth)
	fmt.Println(ImageLength)
}

The output from above program is:

NIKON XXXXX <nil>
"300/1"
"300/1"
2
<nil>
<nil>
160
120

While it's correct dimension is 4608 x 3072.

[llanc]

I saw a library from https://github.com/gavinwade12/nef2jpeg that can convert NEF to JPG normally: https://github.com/jeremytorres/rawparser

My test results：
NEF

JPG

[llanc]

#284