Trying to Load and Save 16-bit x3 color (RGB) TIFF Images ... Unsuccessfully?

Share icon

Sun, 06/26/2016 - 08:59 pm

Basic issue is two-fold:

1) I can't seem to save 48-bit TIFF images. 16-bit just saves a 16-bit greyscale of an NxMx3 wave instead of color. Putting in /DS=48 reverts to a default (?) 8-bit greyscale. Command attempt (or /DS=48): ImageSave /DS=16 /Q=1 /T="tiff" MasterImage as (s_image_path+s_image_folder+"Master.tiff") 2) I can't seem to properly load correctly saved (from Photoshop) 48-bit TIFF images. They load as 3-color, but revert to 8-bit (pixel values between 0 and 255), and they look like a pointillism-ist's dream. I'm sure there has to be a way to do this, but I can't figure it out! If it matters, I'm using the latest v7 beta, but I had this issue in v6, too (with the /D flag instead of /DS for saving).
If you are running IP7 beta you should follow the mechanism for reporting a problem that was described in the beta instructions. Specifically use the Help menu in the application to generate an email to support@wavemetrics.com. The email would include information that is important in analyzing the problem. I'd also appreciate a copy of the image that you are trying to load.

Testing in IP7:
I created a 48-bit image using:
Make/w/u/n=(100,200,3) ddd=10000*(z+1)

Saved it into a 48-bit image:
ImageSave/T="tiff"/DS=16 ddd as "ddd.tif"

and loaded it back using:
ImageLoad/T=tiff/Q/bigt=0 "Macintosh HD:Users:ag:Desktop:ddd.tif"


In IGOR 6.x if your 48-bit TIFF file is written with samplesPerPixel=3 it would be read by IGOR into a 3-layer RGB wave of type unsigned short. Since I do not have your image, I can only suggest that you run your load command with /RAT and then take a look at the tags.

If you see different results or to report anything else relating to IP7 please contact support@wavemetrics.com.

A.G.
WaveMetrics, Inc.

June 27, 2016 at 09:48 am - Permalink

a) It wasn't a bug specifically with Igor 7, I assumed that since I could never do it in 6, that I was doing it wrong in 7.

b) The issue was /bigt=0. Setting that, and it loads perfectly fine. So it's Igor's library that works, the generic one that doesn't.

c) No idea why the saving now works. I wonder if it's because of the exact wave type before, that it needs to be unsigned 16-byte specifically?

d) A sample image was in my previous reply, but now that this works ... it works.

June 27, 2016 at 10:07 am - Permalink

FWIW: IP7 (after the nightly build) will also handle your command so you would not need /bigt=0.

I have no idea why IP6 did not work for you. When you encounter such difficulty you should contact support with the file in question.

A.G.
WaveMetrics, Inc.

June 27, 2016 at 11:59 am - Permalink