SF HDR and compressed tiff

[Gregory C]

I've run into a problem.

I want to save my 4000 dpi HDR files to DVD-R disc. it turns out that a 36-frame roll of 35mm film is *just* larger than a DVD-R disc. I could omit one frame from each DVD but that's not convenient.

one option I have thought of is to use GraphicConverter to save the HDR tif files with LZW compression. the question though is if I do this, will SF HDR be able to open the files and will the HiRepp data still be usable by SF HDR.

I was hoping to save both HDR and 300 dpi corrected versions one roll of film on each disc. maybe LZW compression will allow me to do that.


so can HDR open LZW compressed HDR files?

regards
Gregory

[Gregory C]

if I open one of my HDR tif files in GraphicConverter and save a copy without any changes, in exactly the same format, the new file is half the size of the HDR file. a digital comparison of the two files via GraphicConverter/Edit/Compare pictures shows that the images are identical.

HDR tif file:
TIFF, No compression, Striped (1), Non Planar
Memory 78.5MB
File 125MB

Save as tif file (with same enclosed preview)
TIFF, No compression, Striped (3642), Non Planar
Memory 78.5MB
File 62.6MB

why is there a (huge) difference? is it the HiRepp data? where is the HiRepp data saved?

when using SF HDR, does having HiRepp data only increase the preview speed or does it increase the final processing speed too?

what does Striped (3642) mean?

regards
Gregory

[President_LSI]

SF HDR 16 bit Compression

Dear Gregory,

we will shortly release an new product called "SilverFast HDR Studio" which will have JPEG 2000 compression (among other new features) with up to 7 times the compression speed of Photoshop. This version will also have lossless compression. An upgrade from SF HDR to Sf HDR Studio will be available.

LZW compression for raw data does not make sense and speeds will be slow. LZW is suitable for Line Art and GreyScale images. The new SilverFast JPEG 2000 format is very fast running the compression and extremely fast (close to HiRePP) in opening the file.

best regards

Karl-Heinz Zahorsky

[Gregory C]

does this mean that:

(a) with JPEG 2000 compression, we won't need to use the HiRepp format (ie, HDR) ?

(b) I can use GraphicConverter to convert my raw HDR tif files to JPEG 2000 and be able to open them in SF HDR Studio when it's released?

(c) the new JPEG 2000 format will produce smaller HDR files than the current HDR tif format? if the size of my 35mm HDR images are currently 125MB, what might the size of the new JPEG 2000 HDR images be?


regards
Gregory

[President_LSI]

SF HDR Studio and 16/48 bit Compression

Dear Gregory,

Now there will be two choices of compression with SF HDR Studio and JPEG 2000 into true 16/48 bit HDR or 16/48bit Colour format :

1. HDR Lossless compression (125 MB becomes 63 MB) Time G5: 1:18
2. HDR Lossy compression HQ (125 MB becomes 6 MB) Time G5: 48S

HQ means high quality which will be a factor of 10:1, where with our true 16/48 bit processing and compression, loss of quality will be insignificant.

The old HDR JPEg compression will also be there.
(125 Mb becomes 11 MB)
We have not tested yet whether Graphic Converter can read our files or vice versa, although we are working with a standard implementation of JPEG 2000.

SF HDR will still be preferred to open HiRePP implemented files which will still be significant faster especially when files are very large.

best regards

Karl-Heinz Zahorsky

[Gregory C]

hello Mr Zahorsky.

thank you for taking the time to provide the great answers.

this is all pretty new to me and I'm still trying to understand different aspects of it. unfortunately, the HDR tif files are just too large to allow me to save one 'roll' of film to a single DVD-R disc so I have to work through this and find the best solution.

are the current HDR tif files 48 bit? that might explain why the files saved by GraphicConverter (ie, GC) are so much smaller even in the same non-compressed tif format. GC appears to only support up to 32 bit. when using GC to convert an HDR 48 bit tif file to jp2 (100% Quality), the file size drops from 125MB to just 9MB. however, I assume that 32 bit HDR files (ie; my 'digital negative film') will not be very useful if we need to re-open them in SF HDR sometime in the future. we probably really need to be have 48 bit HDR files.

when scanning film with SF Ai, will we need to save the scans as raw HDR tif format and then use SF HDR Studio to convert them to raw HDR jp2 format?