>In fact, unlike TIFF and TIFF/EP, DNG is proprietary and I'm under the impression that Adobe never really had any real intention to standardize it. Proof is the recent additions of the undocumented lossy and fast-load options that creates "DNG" files that only Adobe can read back safely.
I don't think this constitutes proof of nefarious intentions. If no DNG 1.4 specification is published, or if the license for the 1.4 functionality changes, I'd be inclined to agree with you. I don't think advancement is proof of anything other than forward thinking and the need for new functionality.
As to "only Adobe can read back safely", I'm not sure exactly what you are talking about. There are two basic issues. If you are speaking about the issue with Fast Load previews becoming unreadable, here is my understanding.
There is a flaw in the existing dcraw code that improperly treats an alternate IFD as the main IFD. (I think this has been corrected in newer dcraw code.) Since a lot of software uses dcraw, it makes this a widespread issue. The existing specification outlines how DNG readers should understand IFDs. Here's the relevant part of the 1.2 spec as I understand it.
"DNG 1.2.0.0 allows a new value for NewSubFileType equal to 10001.H. This value, used for alternative or non-primary rendered previews, allows for multiple renderings (not just multiple sizes of a single rendering) to be stored in a DNG file. DNG reading software that displays a preview for a DNG file should, by default, display a preview from an IFD with NewSubFileType equal to 1. Alternative renderings should only be displayed if requested by the user."
I believe that dcraw was grabbing the wrong IFD because it was not paying proper attention to the tag.
If your objection is based on the new lossy compressed options, then I'd simply say to wait a little while and see if Adobe continues to do what they have always done so far - fully document the changes and release free SDK code for other applications to make use of (some of) the new functionality.
As to the addition of lossy source image data, it's my understanding that this allows DNG to be a more suitable container for JPEG originals. There is a significant file size economy, which will be useful at times. I'm personally very happy about this addition, since it allows JPEG shooters to store their parametrically edited images in a more appropriate format. (I personally believe that stuffing the EDL back into the JPEG header is a bad hack.) There are other really good and interesting ways for lossy compression to be of use that anyone here should be able to imagine with a little thought.
You are certainly free to believe that any advancement in the specification is prima facie evidence that Adobe is up to no good. It is my hope that they will document and license the new DNG capabilities as they have done for the last few revisions, and that these capabilities will be used by many different software and hardware vendors in valuable ways. i think they have a good track record in this regard.
As to the ISO stuff, if you are really curious, then I suggest you ask them what's up.
>In fact, unlike TIFF and TIFF/EP, DNG is proprietary and I'm under the impression that Adobe never really had any real intention to standardize it. Proof is the recent additions of the undocumented lossy and fast-load options that creates "DNG" files that only Adobe can read back safely.
I don't think this constitutes proof of nefarious intentions. If no DNG 1.4 specification is published, or if the license for the 1.4 functionality changes, I'd be inclined to agree with you. I don't think advancement is proof of anything other than forward thinking and the need for new functionality.
As to "only Adobe can read back safely", I'm not sure exactly what you are talking about. There are two basic issues. If you are speaking about the issue with Fast Load previews becoming unreadable, here is my understanding.
There is a flaw in the existing dcraw code that improperly treats an alternate IFD as the main IFD. (I think this has been corrected in newer dcraw code.) Since a lot of software uses dcraw, it makes this a widespread issue. The existing specification outlines how DNG readers should understand IFDs. Here's the relevant part of the 1.2 spec as I understand it.
"DNG 1.2.0.0 allows a new value for NewSubFileType equal to 10001.H. This value, used for alternative or non-primary rendered previews, allows for multiple renderings (not just multiple sizes of a single rendering) to be stored in a DNG file. DNG reading software that displays a preview for a DNG file should, by default, display a preview from an IFD with NewSubFileType equal to 1. Alternative renderings should only be displayed if requested by the user."
I believe that dcraw was grabbing the wrong IFD because it was not paying proper attention to the tag.
If your objection is based on the new lossy compressed options, then I'd simply say to wait a little while and see if Adobe continues to do what they have always done so far - fully document the changes and release free SDK code for other applications to make use of (some of) the new functionality.
As to the addition of lossy source image data, it's my understanding that this allows DNG to be a more suitable container for JPEG originals. There is a significant file size economy, which will be useful at times. I'm personally very happy about this addition, since it allows JPEG shooters to store their parametrically edited images in a more appropriate format. (I personally believe that stuffing the EDL back into the JPEG header is a bad hack.) There are other really good and interesting ways for lossy compression to be of use that anyone here should be able to imagine with a little thought.
You are certainly free to believe that any advancement in the specification is prima facie evidence that Adobe is up to no good. It is my hope that they will document and license the new DNG capabilities as they have done for the last few revisions, and that these capabilities will be used by many different software and hardware vendors in valuable ways. i think they have a good track record in this regard.
As to the ISO stuff, if you are really curious, then I suggest you ask them what's up.
Peter