Re: [Gimp-user] Opening raw images in GIMP


It pays to make no assumptions about folks one meets online (in forums,
Twitter, etc.)

Rick Kline
Data Manager (ret.) <-- !
Spacecraft Planetary Imaging Facility, Cornell University <-- !!!!

Indeed :-)

I followed Stave Liam's method and it does mostly work (using Emily
Lakdawalla's test image I saw mostly what she sees in her Photoshop process
though there is "missing" data--you'll see what I mean if you do this).
Biggest issue is that GIMP, as she says, makes assumptions about data
encoding and the only options in the GIMP open dialog where you specify
information about the image provides no options that seem relevant to the
way the data is encoded in the .img file.

Liam mentions G'MIC and you may have more success there. It, like GIMP, is
free and, more importantly, it has far more options related to image data
content (it's written by imaging data scientists for use in manipulating
scientific image data). And it's scriptable already! A steep learning curve
for someone like me with no background in such things, but for you and your
background it may be just what you're looking for (and I can attest that
G'MIC developers are veyr nice people who are approachable if you have
questions). If you're comfortable with a command line (and I can't imagine
you are not given your background) G'MIC may save you a fair bit of time.



Guy Stalnaker
jimmyg521 gmail com

On Wed, Jan 30, 2019 at 12:18 PM Rick Kline <rick kline ms> wrote:

Thanks, Liam,

I like the “change the file type” method best, because there’s no messing
with the contents. Easy enough to find header size (offset) - look at the
file info, Lines x Samples x bytes (16 bit image = 2 bytes). Subtract
result from actual file size and you have the header size.

In PDS images, the ^image (“hat image”) parameter tells what byte the
image starts on. I used to use that in P’shop when importing uncompressed
(.img) PDS images. Even wrote some scripts for P’shop and NIH Image (now
Image J) to import Viking Orbiter, Viking Lander, and Magellan images that
used ^image. Those scripts are probably long gone, and I’m retired from the
Astro job. May have to contact my also retired work friend known as Dr.
Bithead to get some help with script writing for GIMP.

I’ll give the .data trick a try.


Rick Kline
Data Manager (ret.)
Spacecraft Planetary Imaging Facility, Cornell University

 * * ** *** ***** ******** ************* *********************
It’s better to wave at a stranger than to ignore a friend
 * * ** *** ***** ******** ************* *********************

On Jan 29, 2019, at 9:42 PM, Liam R E Quin <liam holoweb net> wrote:

On Tue, 2019-01-29 at 11:43 -0500, Rick Kline wrote:

Some folks working with planetary data would like to use raw PDS may help. It needs to be updated to handle 16-
bit images now that GIMP can open them.

it’s also possible to use ImageMagick or g'mic to conver the VICAR/PDS
raw images to PNG, although you may need to use a hex (or octal) editor
to work out where the image starts exactly. You can also name the image and open it in GIMP, and the pop-up window will ask you
for an offest and the format.

Hope this helps,

slave liam

Liam Quin - web slave for
with fabulous vintage art and fascinating texts to read.
Click here to have the slave beaten.

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