Does Lightroom produce better JPEGs than ImageMagick when converting RAW files?
Asked 9/30/2012
4 views
2 answers
0
When converting a RAW file such as a CR2 to JPEG, is there a quality difference between using Adobe Lightroom and ImageMagick? I'm especially wondering whether exporting at "100% JPEG quality" means the same thing in both programs, and whether the final image quality would differ in any meaningful way.
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
13y ago
2 Answers
10
There are two aspects to your question, because "converting" from RAW to JPEG isn't a simple thing — it's an interpretive process.
So, your results are likely be significantly different. ImageMagick just uses the rudimentary raw conversion from dcraw, and doesn't appear to give you much control over that. Lightroom uses Adobe's rather sophisticated RAW converter, and gives a great deal of control over conversion choices.
The second question is whether "100% jpeg" means the same thing in both of these programs, and the answer there is "no, it doesn't". But, at that level, I'll be shocked if anyone can tell the difference visually even with very careful inspection. The filesize may vary, but there won't be any really meaningful difference.
Originally by user1943. Source · Licensed CC BY-SA 4.0
user1943
13y ago
0
Generated from our catalog & community — verify before relying on it.
Yes—mainly because RAW-to-JPEG conversion is not a simple file format change. A RAW file has to be interpreted and rendered, and different software uses different RAW processing engines and defaults.
Based on the answers, ImageMagick relies on a basic dcraw-style conversion with limited control, while Lightroom uses Adobe’s more advanced RAW converter and gives you much more control over how the image is rendered. That means the JPEGs can look significantly different before JPEG compression is even considered.
As for "100% JPEG quality," that setting is not standardized across programs, so 100% in Lightroom does not necessarily equal 100% in ImageMagick. File sizes may differ.
However, at very high JPEG quality settings, the compression difference itself is unlikely to be meaningfully visible. In practice, the bigger quality difference comes from the RAW conversion process, not the final JPEG quality slider.
Recommended products
UniqueBot
AI13y ago
Your Answer
Related Questions
Why won't Lightroom import Canon 450D RAW+JPEG files, while RAW-only files work?
What’s the practical difference between Canon in-camera JPEGs and JPEGs exported from Lightroom from the same RAW file?
Does exporting JPEG directly from Lightroom give better quality than converting a Lightroom TIFF with ImageMagick?
What JPEG export quality should I use in Lightroom to preserve the original quality?
Can I save a RAW photo as a lossless JPEG for printing in GIMP?