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New M DNG compression


stevegoldenberg

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Hi everyone,

 

I just got my new M (and it's AMAZING) and I have a question: is there any downside to using the compressed DNG? The instructions say that the compression is loss-less which sounds good but I'm curious if there are any negatives of using it? Are there any downsides?

 

-Steve

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Hi everyone,

 

I just got my new M (and it's AMAZING) and I have a question: is there any downside to using the compressed DNG? The instructions say that the compression is loss-less which sounds good but I'm curious if there are any negatives of using it? Are there any downsides?

 

-Steve

 

HI Steve

I also understand it's lossless - I've not done any really detailed comparison, but it seems to me that if it's lost anything I can do without it!:)

 

Enjoy your new camera.

all the best

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To me the definition of compression means something is lost. My gosh memory is so cheap if I need another TB of backup over many years of M use I do not care.

 

Jono's images are superb so for him it's OK. I am a duffer and as such I need all the help I can get.

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To me the definition of compression means something is lost. My gosh memory is so cheap if I need another TB of backup over many years of M use I do not care.

 

Lossless compression is a well established technique that allows the data to be completely reconstructed (see Lossless compression - Wikipedia).

 

The best real-world analogy I can come up with are those vacuum storage bags, where you remove the air from the packaged goods (usually clothes, blankets, cushions, etc.) in order to save storage space.

 

As already pointed out using lossless compression on the 240 does not only save space on the card and on disk but also allows the camera to write the files to the card more quickly.

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Point well taken on all counts.

 

So what if in 3-5 years some new ACR becomes available that takes old uncompressed files to a new level and gives them a new lease on life, but does nothing to improve on lossless images because the air has already been sucked out of them?

 

As for writing files to the card more quickly, I dare say it is SD card development that helps more than about anything else. A couple of nano-seconds for me is not an improvement and I will gladly wait that long while I take in the scene before me.

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To me the definition of compression means something is lost. My gosh memory is so cheap if I need another TB of backup over many years of M use I do not care.

 

Jono's images are superb so for him it's OK. I am a duffer and as such I need all the help I can get.

 

Modern lossless compression algorithms are truly lossless. The most commonly used is probably zip and it's variants.

 

A simple example, if the next 100 characters are '0', noting '0' X 100 is smaller than 100 0's, and completely lossless when decompressed.

 

The network pages you use to read this are lossless compressed.

 

There is no downside that I can think of to lossless compressed if it is available. The extra computing time is made up by smaller data transfer.

 

Regards ... H

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So why does Leica offer uncompressed as an image option on the M if there is nothing to gain from uncompressed over compressed?

Hard to say, but nearly all the camera vendors offer the option of storing either uncompressed or losslessly compressed data. I couldn’t say why one would choose the uncompressed option.

 

One could argue that a few damaged bits within a compressed file might render the file unreadable while a similar damage would only affect a few pixels of an uncompressed file. In practice I have never come across a case where this made a difference, though.

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So what if in 3-5 years some new ACR becomes available that takes old uncompressed files to a new level and gives them a new lease on life, but does nothing to improve on lossless images because the air has already been sucked out of them?

‘Lossless’ means that you can reconstruct the original data from the compressed file – there is absolutely no difference between the original and the decompressed data. If there was a difference than the compression wouldn’t be lossless. Typical image files can be losslessly compressed to about 40 to 70 percent of their original file size.

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Hi everyone,

 

I just got my new M (and it's AMAZING) and I have a question: is there any downside to using the compressed DNG? The instructions say that the compression is loss-less which sounds good but I'm curious if there are any negatives of using it? Are there any downsides?

 

-Steve

 

 

Lossless compression is just that: lossless.

 

It means that there is an algorithm at work that can convert the two representations,

namely uncompressed and compressed, into each other without loss of information.

Of course doing so requires a bit of computational processing power that the M has.

The M9 doesn't have that processing power and therefore offers only lossy compression.

 

So, In order to use lossless compression requires more processing power than using lossy compression.

I wouldn't call that a downside but instead call it a requirement.

Of course, that also requires more energy, therefore a larger battery.

Here is your downside.

 

If the necessary processing power is available,

then using it and compressing the data losslessly before moving and storing it,

is typically more efficient.

One uses one commodity, namely compute or processing power,

in order to reduce the requirements for communication bandwidth and data storage.

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Thank you Harold.

 

So why does Leica offer uncompressed as an image option on the M if there is nothing to gain from uncompressed over compressed?

 

I believe that some older software tools can't open lossless compressed DNG files.

 

- Steve

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I believe that some older software tools can't open lossless compressed DNG files.

But then, any software supporting the new M wouldn’t be one of those older apps.

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Lossless compression is just that: lossless.

 

Lossless Compression is just that: compression.

 

So far no one can answer for me this simple question.

 

If it's a no brainer to use lossless compression then why give us the choice? Why even have the line item with 2 choices?

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Lossless Compression is just that: compression.

 

So far no one can answer for me this simple question.

 

If it's a no brainer to use lossless compression then why give us the choice? Why even have the line item with 2 choices?

 

If you use software which does not handle files which are compressed, do not compress the files.

 

If you use software which does handle compressed files, compress the files.

 

It's all been said in this thread before.

 

A simple question is just that: a question.

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I prefer to use my Photoshop CS 5, where the last ACR version for it is 6.7, as Adobe releases no newer ACR suitable for CS 5. And therefore I open my uncompressed DNG files from the M 9 with CS 5 and do all necessary work with it and not with LR 4. This workflow will not be possible any more with loseless compressed DNGs of the M, if I understand right. Seems that two options remain, if DNGs should be processed. Either to use the uncompressed DNGs and to do all work in CS 5 or to use LR 4 (actual version LR 4.4) and the loseless compressed format at least for opening and converting the files (if I want to work with them in my CS 5).

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