I subscribe to Ask Tim Grey's daily newsletter in which he answers readers' questions, and today's email is about Topaz JPEG to RAW. Here is Tim's text:
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Today's QuestionI got an email about software from Topaz Labs that claims to convert JPEG images to raw captures. Is that even possible, and if so will it provide all of the benefits of raw?
Tim's Quick Answer:The "JPEG to RAW AI" software from Topaz Labs does not provide the same benefits as a raw capture, and frankly I feel that their marketing around this software is misleading.
More Detail:"JPEG to RAW AI" from Topaz Labs enables you to batch process JPEG images and convert them to a DNG or TIFF image with a 16-bit per channel bit depth. As part of the processing, various enhancements are applied to the image. The claim is that the result will be greater dynamic range, a larger color space, higher bit depth, reduced artifacts, and increased detail.
To begin with, converting a JPEG image to a DNG or TIFF file format with a different color space and higher bit-depth setting does not provide any quality benefit for the image all by itself. The only real benefit from these changes would be the potential for better image quality after applying strong adjustments. The exact same results could be achieved by changing the color space and bit depth for an image in Photoshop, for example, with no visible change in appearance for the photo.
After testing a variety of images with JPEG to RAW AI, I did not find that there was any significant improvement in the level of detail in the photos. Some photos showed evidence of contrast enhancement and sharpening in certain areas, which obviously could also be applied using other software.
While some of the visible artifacts in JPEG images I tested with JPEG to RAW AI were reduced, in areas where artifacts were reduced overall sharpness and detail were also reduced. In some cases detail enhancement in certain areas of an image actually increased the visibility of artifacts in the image.
Overall I was not impressed with the results I achieved with the JPEG images I processed with JPEG to RAW AI. More worrisome to me, however, is that I feel the way the product is being marketed is misleading. While I do feel that some of the software products from Topaz Labs are very good, I would not recommend JPEG to RAW AI.
If you'd like to check out JPEG to RAW AI for yourself, you can get more info on the Topaz Labs website here:
https://topazlabs.com/jpeg-to-raw-ai/ref/273/ >>
It seems that Tim tested the application with at least several sample photos to come to these conclusions.
Beyond what Tim reports, I wonder just how much quality enhancement inventing data can provide. To some extent and depending on the operations being performed, it can be useful; but we need to be mindful that for many of our cameras, bit depth exceeds JPEG bit-depth and the JPEG has already eliminated much of the scene referred raw data that a camera sensor records, so any processing already starts with that disadvantage, which would most likely make a visible difference to image quality the more the photo is processed and magnified. Of course the only way to know for sure whether this application does good things for us is to try it in the context of our own requirements and see. I won't be doing so because none of my photography uses JPEG as the initial capture format. I only record raw files and periodically convert some photos to JPEG as useful for transmission over the Internet.