[gdal-dev] Re: Gdal Bug? was: Re: JP2MRSID Issues

[Rahkonen Jukka]

Stephen Woodbridge wrote:
 
Jukka Rahkonen wrote:

 
>> Hi, 
>> 
>> There is absolutely something basically wrong.  For that little files conversion
>> to GeoTIFF should take perhaps 5 minutes.  Try skipping more drivers and see how
>> Kakadu driver performs.  If you want to know how fast it can be, download Kakadu
>> win32 executables from www.kakadusoftware.com and measure how long it takes to
>> expand your images to GeoTIFFs with kdu_expand.  

> Hi Jukka,

> Thank you for that pointer. I grabbed the linux version and kdu_expand 
> is really fast!!! 2 mins if the source file is not cached and 55 sec if 
> it is cached by the file system. But is only is expanding the first 
> band, do you know how I can get it to expand bands 1,2,3 into the tiff 
> as r,g,b? If I can do that then I could just use that as an interim step 
> to expand the jp2 into a tif and then do the gdalwarp based on that.

Hi,

Kakadu executables are demonstration programs showing some examples about what can be done with Kakadu SDK. They are working and effective programs but not user friendly and not even meant to be such. Another problem is that jpeg2000 is not extremely easy to understand. At least I consider it complicated. Have a try with reading what you get by giving kdu_compress -usage, or kdu_expand -usage, or by reading the usage_examples.txt file that you probably have now :)

Without knowing how your jpeg2000 original is made it is hard to say how you could take out the three channels you want with kdu_expand.  This might do it channel by channel, but you would need to construct three individual files together to make a colour image:
c:\kakadu60\kdu_expand -raw_components -skip_components 0 -i input.jp2 -o red.tif
c:\kakadu60\kdu_expand -raw_components -skip_components 1 -i input.jp2 -o green.tif
c:\kakadu60\kdu_expand -raw_components -skip_components 2 -i input.jp2 -o blue.tif

But this is gdal-dev mailing list (Kakadu users Yahoo group exists but it is rather quit) and I can say that I have used gdal for converting jpeg2000 images to other formats a lot and for me it has worked fine. Our images are mostly 3-channel aerial photos which are easier to handle than yours 4-channel images, but also 7-band Landsat mosaics. You should be able to do fine with gdal.

If you can show me a place where I could download one of your images I could have a try with it some day.

-Jukka Rahkonen-