Legacy ImageMagick Discussions Archive

Can dcraw create 32 bit/channel files? I didn't know that. I do not know that either. I may have read too much into the OP's request and discussion of 32-bit data. No dcraw is 16bit output only afaik, which is why I mention libraw and rawspeed and outputing 4x 16bit raw channels or 32bit where ...

Aim is to avoid going raw into a linear 'gamma' file format due to suspected loss of precision in shadows hence Log but maximising data in 16bit format. Why would you lose precision in the shadows? Any integer format will potentially lose precision, but not especially in the shadows, I think. My ...

Oh my bad, I thought IM did logluv, now discovered however it was pfstools. So that leaves lin to log, I can export four 16bit greyscale tiffs with libraw: 4channnels - splits RAW-file into four separate 16-bit grayscale TIFFs (per RAW channel). Command line switches: -s N selects N-th image from ...

Hi Is it possible using a hdri build of IM, Q32 if necessary Q16 otherwise to 'develop' camera raw format supported by dcraw, libraw and rawspeed and write 16bit Logluv tiffs, reason is to retain, hate to use this tired and overused phrase but retain the 'dynamic range' of a raw file but bake ...

If you know what the color space of an image is then you could use -set colorspace sRGB -colorpace XYZ ? If you want to keep track of an images colorspace you could use ICC profiles, they're available from the ICC website and using IM's -profile feature, download the ICC required and drop into the ...

snibgo, many thanks for the link, I've downloaded and using now, bigger memory footprint than non hdri I think as now my batch processing has to be shorter image sequence batches, so therefore more batches to process than with a Q16 to stay within my available memory but great all the same. magick ...

ok, thanks but unfortuneatly magick.exe 7.00 is crashing for me where as IM 6 latest version Convert works. I'll have to try and find a Windows 32bit hdri of latest 6 version or try compiling via MingW as i'm on Linux but using Windows 32bit binaries via Wine. I'd better wait on IM 7 for a more ...

Many thanks.

**EDIT**

Ok, Convert.exe seems to be missing, have things changed in this release or at least the .dll package, I'll try the other downloads in the alpha link.

hi

I've searched and tried to find either a Windows 32bit build of IM with 'hdri' enabled or IM 7 32bit Windows build which I believe will have 'hdri' as a default build option.

Many thanks

I'm aware IM can write EXR's of the RGB variety can it also export sub sampled and non sub sampled YCbCr luminance / chrominance as an alternative. Also is there an option to write and sequence of EXR's to one file rather than the usual sequential numbered output I'm currently using. many thanks

Back again. :-) I have a query regarding the positioning of the RGB48 data into 32bit hdr format float EXR's based on fmw42's post below. Is it possible to position the RGB48 linear light data piped from Avisynth and center it in the larger 32bit range of levels to leave head and foot room for ...

hi Is it possible to analyse an image, locate the pixel values which are in levels 255 down to 200 in each channel and write them to either a text file with coordinates and pixel value, assume from reading done so far PPM and that has no resolution, just a list of coords and pixel values or image ...

hi I'm piping raw 48bit RGB video frames from avisynth to linear EXR via IM successfully thanks to help on this forum. :-) But I now have a new twist to the process which is videos shot with interleaved exposures of set EV within the video frames ie: dark frame -> light frame -> dark frame etc. Dark ...

Ok, reading the documentation on memory usage and really big files, adding -limit memory 500MiB -limit map 1GiB appears to be helping, good approach or better one available? Does require h/d space for temporary storage of files but doesn't appear to slow the process down too much.

I've been using Avisynth -> AVS2yuv -> Imagemagick for sometime but having problems piping larger video files due to memory errors, running out of memory before the image writing starts. Is there anyway to get IM to start processing and writing files, clearing memory whilst the pipe from AVS2yuv is ...