Tip: JPEG shooters - lossless saving

[Onyx]

MattK, Vicareyus and myself are about the only ones known to me to be predominantly JPEG shooters. You guys pay attention - especially if you're heavily into post processing!

The following is a segment shamelessly ripped from an email written by an employee of Nikon's software division.

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One additional option you have when using Nikon Capture is to save as a NEF file. If you start with a JPEG file, make some adjustments, and choose "Save As", you can save that file as "filename.nef". This will save your ORIGINAL JPEG DATA inside a NEF file, along with all of your changes. This means that you will not lose any quality from saving multiple times because the image data is not being recompressed each time. When you reopen the NEF file, the original JPEG data will be opened again, and the changes will be reapplied. Using this method, you can work on an image in several sessions, and only recompress and save as JPEG when you are completely finished with it. Also, the NEF file will only be slightly larger than the original JPEG file.

Steven Pont
Nikon Capture Lead Engineer

[sirhc55]

Absolutely true but for one fact - jpeg is a lossy compression so even if you save to a NEF file you are only saving the jpeg information. The jpeg compression happens within the camera.

If you require jpeg it is always better to obtain from the cleanest source so shoot RAW and save down to jpeg - you cannot save up from jpeg

Chris

[Onyx]

Sorry, I think I might have cut out too much from the original quote.

This was intended to address the issue of heavy photoshoping/editing - the save/resave of changes that results in detail losses each time. It's doing away with the losses of jpeg compression as a result of image manipulation, not intended as a means of competing with NEF as a format.

[sirhc55]

Gotcha Onyx now I understand and agree.

Chris

[Matt. K]

Interesting! Thanks for the post. We look, learn and grow.

[Vicareyus]

Thanks Onyx...interesting. But, being a true luddite (albeit one who has embraced digital photography with great enthusiam)...its all a bit complicated for me! I confess I dont actually use Nikon Capture - I just read from the card directly into Adobe Photoshop Album (which I really like as an organising tool) and if I want to edit then I do so in Photoshop, but I always save the edited image as a copy, so never over-write the original image - I believe in this way I always at least have the original JPG unaltered to play with again.

I understand from my reading that RAW would give me more data, and more possibilities, but that I'd probably have to do more pp on each and every image to get a passable looking image. I've goota be honest and say that I don't have enough time to spend hours editing a few images - if I cant do it in a few simple steps (and presumably therefore with little data loss), then I'm probably never going to get around to it.

If I generate a big pile of images in a "pending" folder (ie folder says - "will pp in detail when I get around to it") then these are probably the images that will be in this folder for a long time to come.

Vic

[Greg B]

If I am starting with a jpg, the first thing I do is save it as an uncompressed tiff, and save each stage as an uncompressed tiff. I guess its pretty much the same thing. Downside is tiffs are probably bigger than nefs. Upside is they can be easily opened in any program, don't need nef support.

[phillipb]

Vic
My suggestion is that you give RAW a try, it cost nothing and you may find that you don't need to do as much PP as you are led to believe.

[Vicareyus]

hmm...OK...maybe I'll shoot a few "in the RAW" and see what happens...
Vic

[Onyx]

You'll be back to good ol' jpeg in no time Vic! I dislike PP probably as much as you do, and try to avoid raw unless I'm in unfamiliar territory.

[Nnnnsic]

Add me to the list, Onyx.
I shoot mostly in jpeg as it's the only option available that's fast enough for my movie making.

[lukeo]

Any decent graphic software made from about the year 2002 onwards does not re compress a JPG file every time it is opened / saved.

The only time it get recompressed is when you apply filters etc and alter the colours of the image.

Saving JPG in RAW format is a myth, for JPG to exist it must be compressed and each time you alter and save such an image it will lose data from the original. You cannot have lossless JPG it's a contradiction in terms.

I am sorry I disagree, its akin to renaming a .MP3 file a .WAV it doesn't magically restore the data lost when the MP3 was created as like JPG, MP3 is inherently lossy.

File extension higgery pokery just doesn't work. It's a nice idea though, shoot in RAW to get a feel for your environment, get your whitebalance happy (something you cannot change post shoot with JPG) and then once you know your situation switch to JPG ... if you need to.

Just my two cents worth for my first post

[Raydar]

Thanks Onyx

Good read & something to think about having a go at.

Cheers
Ray

[jethro]

jpeg is definately a once off compression. as the camera does it for you, you must save the image as a tif or whatever you require for the end purpose. But if you save as a tiff and in the save menu you will see LZW compression. check this box and your file size will dramatically reduce in size and it will not kill the image data. i use this method every day. jpeg compression will effect image quality if it is re-saved as a jpeg. the loss will be roughly 1-2% per time obviously increasing with each save.

[sirhc55]

I quote the following by Mike Chaney:

What's the Bottom Line?:


The JPEG image format offers a way to save images using less space, but with some loss in image quality. Typically, a first generation save will be almost as good as a lossless TIFF as long as you use quality levels close to the highest available. Some "die hards" claim that you should never use a camera in JPEG mode when you have TIFF or RAW available as an option, and one cannot argue that you get the best quality and best editing capability with TIFF or RAW when compared to JPEG. That said, JPEG is a perfectly valid format to use even when capturing images the first time in your camera, especially when memory space, shooting speed, or the ability to print images without post processing is important. Remember that JPEG's are processed and ready to view/print, whereas RAW images require post processing to "develop" the images from the raw data. This takes additional time and can complicate your shoot-to-print workflow. A first generation JPEG will offer quality comparable to any other final or ready-to-print format, however, cannot offer latitude for correcting exposure and other shooting issues like a RAW image or a 48 bit TIFF. Bottom line: choose what works for you, but be sure to take the pros/cons of each format into consideration.

Chris

[dooda]

I'm a Jpegger as many here would have guessed. I try and get the shot right away, if not I make adjustments and try again. I've gotten better and better at this to where I'm comfortable in most situations. There are a few situations that I might use RAW, but prefer JPEG Fine. It scares me that saving it as JPEG loses information. I'll take the advice Onyx, thanks.

[sirhc55]

When you are in a photo shoot situation that cannot be repeated - shoot RAW.

The D70 LCD is in effect fairly useless when it comes to knowing whether or not you have a good shot. Also remember that the histogram is not RGB and as such gives a fairly loose interpretation of the final result.

My advice - shoot jpeg if you wish but if shooting something really important shoot RAW which gives a much better chance of retrieving a bad pic.



Chris

[PlatinumWeaver]

My philosphy is to shoot in RAW until i'm running out of room and then carefully shoot in JPEG. This way for the majority of my pics I have the full editting ability you get using RAW and when I've switched over to JPEG I get to take shots that I otherwise would have missed out on if I had run out of room.. in that case anything i've taken is a bonus, even if I would have prefered to have been able to adjust the final shot more...

[gstark]

Dean,

Yes, and don't forget that (once you've switched to JPG) you can always switch to a lower resolution to conserve even more space on your CF card, thus gaining a few more of those "bonus" shots.

Mind you, now that I'm using a 1 GB card as my primary storage, with a 512MB as my secondary, I'm not actually running out of space for images in any relatively short timeframe.

[sirhc55]

Actually Gary I think you have touched on the solution. By having larger compact flash cards there is no real reason to shoot jpeg. Also if the in camera parameters are correct and you shoot the pic correctly then the amount of PP should be very nominal even in the RAW format.

Chris

[Greg B]

Any decent graphic software made from about the year 2002 onwards does not re compress a JPG file every time it is opened / saved.

The only time it get recompressed is when you apply filters etc and alter the colours of the image.

Saving JPG in RAW format is a myth, for JPG to exist it must be compressed and each time you alter and save such an image it will lose data from the original. You cannot have lossless JPG it's a contradiction in terms.

I think this needs some clarification. If you save something as a JPG - it will be compressed. Regardless of your software.

If you have a file which is a JPG, and you save it in a non-compressed format such as uncompressed TIFF, or even as RAW, you will not revert to an uncompressed image, but you will avoid any further compression.

If you have a JPG and don't do anything to it, why would you save it? If you do save it, there will be another compression.

The only "lossless" jpg save is the lossless rotation which some programs allow.

[Greg B]

Dean,

Yes, and don't forget that (once you've switched to JPG) you can always switch to a lower resolution to conserve even more space on your CF card, thus gaining a few more of those "bonus" shots.

Mind you, now that I'm using a 1 GB card as my primary storage, with a 512MB as my secondary, I'm not actually running out of space for images in any relatively short timeframe.

Ditto, and I bought one of those 40 gig portable storage drives from Birdie. I think that means about 600-800 NEF images. Yep, that should be enough

[sirhc55]

Greg - surely a 40Gb HD will hold 3760 NEFs based on 94 per giga!!!



Chris

[xerubus]

Greg - surely a 40Gb HD will hold 3760 NEFs based on 94 per giga!!!



Chris

correct... it's closer to 3800 than 800

[JordanP]

I'd say 6000 plus becasue I have never gotten less than 150 raw files on a gig.

[kipper]

While in France I've been shooting predominantly in JPEG. Tried a few NEF shots but at the moment it's too hard to use the features of wb, exposure, etc control of NEF due to really low resolution and the NEF plugin for PS requires a high resolution to work properly. There have been some shots that I'd have liked to have been taken in NEF but I've managed to recover some shots quite easily in PS given the know how.

[Greg B]

Holy miscalculation Batman.

I believe I have dropped a zero.....

I know the camera says that you have 94 shots with a 1 gig card, which suggests that the files are 10 meg.

However, most of my NEF files seem to be between 4 and 6 meg, let's say 5 meg on average.

I assume the drive in my storage thingy uses that stupid japanese gigabyte which is actually a 1,000,000 kB (how the hell do they get away with that!) or, say 1,000 meg by 40 = 40,000 meg divided by 5 meg (average NEF size) = 8,000 files

How does that look?

[sirhc55]

That’s more like it Batman - I based my figure on the lowest common denominator.

Now go shoot your heart out in RAW - but remember machines guns needed water or air cooling so try not to shoot 8,000 all at once

Chris

[Deano]

While in France I've been shooting predominantly in JPEG. Tried a few NEF shots but at the moment it's too hard to use the features of wb, exposure, etc control of NEF due to really low resolution and the NEF plugin for PS requires a high resolution to work properly. There have been some shots that I'd have liked to have been taken in NEF but I've managed to recover some shots quite easily in PS given the know how.

Don't forget that you can set the D70 to capture both a NEF and JPEG of each shot. It does take more card space but it allows the NEF to be post processed to perfection later and the JPEG is immediately available if, for example, you want a print from the local printing shop without having to PP.

I always shoot raw now but I found this to be a problem on the weekend at the in-laws because I could not pop in to the local print shop for a few prints as I didn't have my computer to process the NEFs. Of course I only thought about this after the fact.

Cheers
Dean

[skippy]

Don't forget that you can set the D70 to capture both a NEF and JPEG of each shot. It does take more card space but it allows the NEF to be post processed to perfection later and the JPEG is immediately available if, for example, you want a print from the local printing shop without having to PP.

This would be my biggest prob with the D70 - RAW+JPG means basic jpg, and I would prefer to be able to choose the jpg setting I want saved with the RAW image. Space isn't an issue, but the local print shop scenario would mean I could use Large Fine jpgs instead of basics. Firmware update maybe? Nikon, are you listening?

[PlatinumWeaver]

When you're shooting RAW+JPG the Jpeg is full resolution but basic quality. I would assume the image would be find for helping you catalogue your files but wouldn't be all that great for getting printed out.

Does anyone actually regularly use this setting?

With regards to changing the size of the image to fit a few more in. I'm happy compromising on quality to a certain degree and going with Jpeg for the last few shots, but I don't know that I'd start to reduce the size.

Depending on how things turn out for X-mas I'm planning on buying a 1gb card from Birdy pretty soon.. that should alleviate most storage issues.. well.. that and a new harddrive..

With regards to compression and Jpegs, there is actually a lossless jpeg format, but from what i've seen it doesn't actually save any space at all, might as well save as .bmp

[Onyx]

JPG basic is actually fairly good for most applications. Certainly good enough for the impulsive 40 cent 6x4 snapshot prints. Personally I can't pick the diff between JPG fine and norm without severe pixel peeping, but norm to basic is noticeable step down, especially at contrast edges. I'd avoid printing from JPG basics, but it's certain holds IQ pretty well compared to PHD cameras.

[beetleboy]

I always shoot RAW + JPG. I know some people may think I'm crazy for doing so but I found flicking between happy snap JPG's and "keep for later editing" NEF's was a pain in the neck.

All I do is run through a slideshow on my lappy post shoot and delete the JPG's that I don't want then I use this as a guide to delete the corresponding NEF's. I then jump into PS File Browser and delete any NEF's that I only plan on keeping as JPG's and PP the others and save into categorised folders. What I'm left with is a folder of happy snap JPG's which I then date and archive.

If you look closely at the "Basic" JPG's you'll actually find that for their 750k-1000k file size they are actually decent quality..I agree that you wouldn't go printing large copies but I've produced perfectly acceptable results at 8x6 inch.

The prints from the Basic JPG's on the D70 actually look better than what I used to produce with my old Fuji S602Z!

[Matt. K]

Greg
Tiff files are huge...is there any good reason why not to save as PSD files? Photoshops own format? Let's face it, PS is going to be around forever.
By the way...I am beginning to shoot more RAW images than I used to as a matter of learning how far I can take the image quality...something I only judge from a print. My unscientific experiments so far indicate to me that there's very little difference between a high quality JPG and a RAW file. However, the RAW file gives more post processing options.

I think the general concensus now is that it's OK to shoot JPG's most of the time but shoot RAW for anything that's important. Then again...it depends on what kind of photographer you are. If you normally shoot a very large number of images then the above advice is probably best. If you are a selective, careful shooter who who only shoots after great delibereation and you don't shoot many images...then shoot RAW.

[Greg B]

This

http://www.jpeg.org/

is the website of the Joint Photographic Experts Group, and may be of interest.

[Matt. K]

Greg
Thanks for link. That's disturbing news. Wonder what the ramifications of this will be. I know the Defence Department were very hot on JPEG 2000 because of its abilities to selectively compress non important parts of the image. Hmmm.

[neurons]

Something else to remember is JPEG introduces subtle colour shifts into the source data as well as artefacting during compression, and obviously all the camera settings are 'baked' into the pixel data. Saving the JPG back out as NEF basically gains nothing you couldn't achieve by saving a PSD with adjustment layers. Non destructive editing should always be a priority for quality data.
If you shoot raw, you can batch process them out to jpgs in one drag &drop anyway, and you'll still have the best source data (in 16 bits after import thru camera raw, or NC) which you could never get back through fiddling with JPG's. You dont nescessarily have to use PP to want to shoot raw, its simply the best storage format for your source data. When you have limitations imposing on that decision such as shooting speed (the only real consideration) or storage space (you're kidding right? CF cards are now £49 per GB ) , or you're outputting straight to print from card (you're not P&S'ing with this thing are you?! ) then switch to JPG. Using raw on any 1/2 decent PC only adds a tiny amount of time to your copying the files off the card & turning them into JPG's anyway if thats your bag!

cheers!

/2ob

[sirhc55]

welcome neurons - fully support what you have said.

I believe that the likes of Nikon and Canon, in their DSLR’s, should have RAW, Fine JPEG and that’s it (maybe uncompressed RAW would be nice)

Chris