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Old August 6th, 2015, 12:18 PM
Doug Kerr Doug Kerr is online now
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Join Date: May 2006
Location: Alamogordo, New Mexico, USA
Posts: 8,390
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Well, here is the report afresh, hopefully correct this time. The change is highlighted in blue (but the images are new also)

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Here we see a visual comparison of a small crop from the JPG files developed (by Photoshop/ACR) from two DNG files, generated by Adobe DNG Converter from same CR2 file generated by my Canon PowerShot G16 camera. The shot was at ISO 400.

The original shot resulted in a JPG image with dimensions of 4000 px 3000 px. The reconstructed JPG images (from the CR2->DNG chain) had those same dimensions.

The crop on the left is developed from a DNG file with normal compression; the one on the right from a DNG file with lossy compression. They are both presented on a pixel-for-pixel basis.



Left: from DNG with normal compression. Right: from DNG with lossy compression.

Both developments were with the default settings of PS/ACR.

I think I would have to say that I find a very slight deterioration in image quality overall from the lossy compression DNG route.

Best regards,

Doug
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