How can I automatically convert Sony RAW (ARW) to JPEGs as good as the camera creates itself?

For Linux you could use exiftool:

exiftool -b -PreviewImage -w _preview.jpg -ext arw <directory>

It treats all arw files in the directory. With an extra -r parameter it also does the sub-directories. The files will have the same name as the arw files but _preview.jpg will be added.

Have you tried using Sony's "Imaging Edge" software?

Most manufacturers' raw developing software opens raw images with the in-camera settings at the time the image was captured applied by default. Canon's Digital Photo Professional and Nikon's Capture NX-D both certainly do.

For Linux, the following all have GUIs you can use to adjust settings and CLI you can script for batch conversion.

• UFRaw
• RawTherapee
• DarkTable

You may also consider trying the camera manufacturer's software with WINE.

Unfortunately, I have been unable to find a tool that creates JPGs similar to what the camera creates.

The issue is noise. Most annoying noise is chroma noise, the second most annoying noise is luma noise.

One option to reduce chroma noise is to do a L+A+B channel decomposition of the image, apply gaussian blur to the A+B channels and combine again. Unfortunately, this is a lot of manual work unless you write a script to do it, and the chroma resolution will be severely affected. The JPG created does not have as good chroma resolution as the ones produced by the camera.

Another option is the profiled denoise module of the open-source software called 'darktable'. It uses noise measured from the camera sensor (that's why it's called profiled), and has options for non-local means or wavelet noise reduction. The wavelet one according to my tests is way too aggressive, reducing the resolution of fine details. The non-local means is by far the best noise reduction algorithm I have found in open-source software. Unfortunately, for high ISO sensitivities, when cropping a small 1500x1000 area from a 24 megapixel 6000x4000 image, the profiled non-local means algorithm may give a slightly painting-like appearance which the noise reduction algorithms in the camera do not do. On the other hand, non-local means will remove more luma noise than what the camera does.

If you don't shoot at high ISO sensitivities using a high-megapixel sensor and subsequently crop a small area from the image (effectively using 'digital zoom'), this issue probably doesn't affect you.

I recently found myself in the same situation, took some RAW shots, not RAW + Jpeg, and now have a ton of photos that I need to improve in order to show anyone.

I've tried a small handful of programs so far- Imaging Edge, Fotor, FastStone Image Viewer.

Here's what I've found-

Imaging Edge works very well. It's made by Sony and going by the logic that "Sony knows Sony", I trust that it knows how to work with it's own camera's images. And the results look pretty good. It's also reasonably fast, 500 pictures took around 30-40 minutes.

FastStone Viewer was nearly as good. I used the "Quality = 100" setting, everything else default. It was as fast, or nearly as fast, as Imaging Edge. The quality was nearly indistinguishable. The jpeg file sizes were much larger, around double the size. FastStone has some other options that could be tweaked that might make more of a difference, but I didn't play with them.

Fotor was not very good. It was VERY slow, taking about 24 hours to convert the photos (it's hard to tell exactly how long, because my laptop kept sleeping after a few hours, and I'm not sure the processing was working in the background.) Also, the resulting photos were very 'noisy'. Some looked ok at the regular size, but when I zoomed in on the photo, there were a LOT of extra color and pixels that distracted from the image. Would not recommend this one.

So, as Michael C says, try the Sony program and see what happens. Imaging Edge is actually three programs (viewer, editor and camera remote control). It's the viewer that I used to batch-output my photos.

Hope that helps.

One of the other answers, by @Marco, has a negative score, and that is the one that I ended up preferring:

exiftool -b -PreviewImage IN.ARW > OUT.jpg

As pointed out in the comments, this has the disadvantage of not preserving the full resolution of the image. On my 14-year-old camera, the preview image extracted by ExifTool is 1616 x 1080, not quite the resolution of my monitor, but good enough for a web page. The other option for me, since I didn't want to use proprietary software, was @xiota's suggestion to use the command line interface of a GUI tool. The tool that I had been using is DarkTable, and the command-line is very simple:

darktable-cli IN.ARW > OUT.jpg

Perhaps for the future, I should read the user's manual and try to get the camera to save high-resolution JPEGs, but for my immediate needs, the exiftool extraction option produced a suitable resolution and far superior colors.

It's unfortunate that, at least in my case, the DarkTable default output is so much lower quality than whatever the software in the camera is producing. However, I guess Sony put a lot of work into their software.

I decided to post this additional answer, because I figured I'm not the only web user who is willing to sacrifice resolution for color quality, and I wanted to make sure that the Marco's answer didn't get ignored or deleted.

Output of DarkTable (originally 4288 x 2856):

Output of ExifTool (originally 1616 x 1080):

Which one would you want to see on a web page?

Also, before you downvote this answer, note that the OP asked for:

• "software (for Linux, eventually Windows) that helps me to have similar effect like auto in my camera (convert arw into jpeg)?"

  (Check. This software produces an identical effect to that of the camera's firmware, because it is extracting the output of that firmware.)

• "I want software to do that and I want to have jpegs as good as camera can process"

  (The jpegs extracted by exiftool are lower resolution than the camera can process - but aside from that, the quality is the same, because they came from the camera. Other answers produced inferior output for my use case)

• "I want software that can choose proper settings like the camera does."

  (In one sense, exiftool is not choosing the settings; in another sense, it is choosing exactly the same settings as the camera...)

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Update: One commenter expressed concern about the compression quality of the preview image. I don't think there's any reason for Sony to use a low quality compression for a preview image. The goal is to have an image that looks good on a small screen, and this is achieved with good compression but lower resolution.

To estimate the compression quality that my camera uses for previews, I used ImageMagick's convert tool:

convert IN.jpg -quality 96 OUT.jpg

I adjusted the quality until the size of the input and output was the same, in this case 508k. This corresponds to a quality of 96 which seems fairly high to me.

For comparison, the RAW image file is 13M, so the preview is adding less than 5% to the file size.