Found iPad app for DNG files

[Julian H]

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A friend of mine thought it was too slow with iPad1 and M8 files. He has not commented on M9 files yet but I guess they are slower still. I think I'll keep with a Macbook, probably a Pro but maybe an Air.

 

Julian

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[stunsworth]

I too tried the lite version, but found it too slow on a v1 iPad to be really useful. That's a pity, but there's not much Sandy can do other than to try to optimise the code, and even then I suspect it's the hardware that's the bottleneck anyhow.

[sandymc]

I too tried the lite version, but found it too slow on a v1 iPad to be really useful. That's a pity, but there's not much Sandy can do other than to try to optimise the code, and even then I suspect it's the hardware that's the bottleneck anyhow.

 

Well, PhotoRaw's speed (or lack thereof) is essentially determined by two things:

 

1. Using a 16 bit processing path - PhotoRaw uses a full 16 bit processing path for demosaicing. It would be a lot faster to process at 8-bits, but the intent of PhotoRaw is to give an image that's comparable to what you'd get by processing on a desktop machine. Using 8 bits just doesn't give you a realistic view of what the final image will (or could) look like.

 

2. Memory. Demosaicing takes a lot of memory. Where this gets complicated is that iOS has a unconventional memory management system. On most operating systems, if the OS gives you memory, then you can use it as you want. With iOS, the OS will give you memory, but then if it runs short of memory due to other things happening, it will simply terminate the app that has the most memory. So, (a) PhotoRaw has to use as little memory as possible, which directly impacts efficiency. But (, in order to avoid being terminated because other apps decide they need memory (which users interpret as PhotoRaw crashing ) PhotoRaw implements virtual memory. Essentially what that does is to use the flash memory (the iPad's "disk") as RAM. Unfortunately, that's really slow. However it does prevent crashes, even with huge images - you can, if you have a lot of time, process images from Phase P65 medium format backs using PhotoRaw.

 

You can switch off virtual memory in PhotoRaw's settings area, which makes it a lot faster, but that risks "crashes".....

 

Regards,

 

Sandy

[stunsworth]

Sandy, thanks. Would there be a possibility of offering 8/16 bit operation as an option?

 

I only ask because perhaps like other people I'm more interested in getting an image I can look at rather than have to rely on shooting DNG + Jpeg.

[sandymc]

Sandy, thanks. Would there be a possibility of offering 8/16 bit operation as an option?

 

I only ask because perhaps like other people I'm more interested in getting an image I can look at rather than have to rely on shooting DNG + Jpeg.

 

Steve,

 

I have thought about it. So far, I've chosen not to, on the basis of image quality, and the complexity of building a dual mode app. Essentially, it would amount to a entirely separate demosaicing module for each mode. But I'll continue to try to think of a simple way to do so........

 

Regards,

 

Sandy

[macjim]

Sandy, I've bought your app — can I suggest a few things to improve its usability please.

The adjustment buttons need to be larger and more visible to help the user as the sliders are to small to comfortably use giving a less than smooth operation, a cancel/go back button is needed to exit the editing mode, and a clear all/ delete button in the import section is needed to clear no longer wanted imports. This would improve its ease of use as the first time I tried editing a RAW file it wouldn't show the editing tools, it also didn't show any way to get back the main window. I had to hit the home button to get out of the app, close it fully, before I could get back in to try editing.

Kind regards

[sandymc]

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Sandy, I've bought your app — can I suggest a few things to improve its usability please.

The adjustment buttons need to be larger and more visible to help the user as the sliders are to small to comfortably use giving a less than smooth operation, a cancel/go back button is needed to exit the editing mode, and a clear all/ delete button in the import section is needed to clear no longer wanted imports. This would improve its ease of use as the first time I tried editing a RAW file it wouldn't show the editing tools, it also didn't show any way to get back the main window. I had to hit the home button to get out of the app, close it fully, before I could get back in to try editing.

Kind regards

 

 

There is a cancel button - bottom left - but it won't show if the HUD (editing controls) don't show. If you get the problem with the editing controls not showing again, please email me (via the "Contact us" button) in the app itself with what you were doing when that happened; emailing from in the app will also send a log file to me.

 

On the usability issues, I assume you're on an iPad? The next version will have larger controls. On the iPhone, its a bit more difficult; there's only so much screen real estate to work with.

 

Regards,

 

Sandy

[macjim]

Yes, I was using it on an iPad. If it happens again I'll email from the app.

 

 

Cheers, Macjim.