The MER Files Options

[Pando]

Here's something of great interest to Doug

Now how's that book coming?

http://pdsimg.jpl.nasa.gov/data/mer/

[djellison]

Woo - and indeed yay I believe the first 30 sols is due 6 months after landing - which is right about now.

Now if only we had an IMG imported for Photoshop

Doug

[slinted]

In looking through all the files there, I'm curious if this is the 'work in progress' of the PDS. It does contain many of the raw files (at least i'm assuming they are raw, since they are in the EDR folder, as opposed to the 'prepared' products which would be RDR's) and their PDS tags. But it is interesting to see all the jpg's, in the ops folders, though they are downsized (understandable, considering the...tremendous volume of files in those folders.)


But we're still going to have to wait for the begining of August for the full release, which will have the calibrated RDR files I think will be the most interesting (and capable of making the most accurate color i'd figure).

I'm looking forward to it!

[Sunspot]

A Comparison

JPEG Image on the MER Website:



IMG File converted to JPEG in NASA View

[djellison]

I take it you used NasaView to read the img?

I must admit - it's so good to see un-butchered imagery

I'm very busy on a 3D project at the moment ( involving an electric land speed record attempt ) - but once the rush for that is over - i'll be looking at the raw imageyr properly

Doug

[Sunspot]

Yep I used NASA View, it allows you to save the files as GIF or JPEG. The original IMG file was 2MB that JPEG is 182K. The GIF I saved from it is about 840K.

[djellison]

Only problem is - that Gif or JPG - you're limited to 8bit greyscale data - and some of the images will be 12 bit Photoshop can handle 12 bit which is just SO frustrating -ARHSAghhgeghaheahfhgh

Surely someone should do an .img Photoshop importer

I think I might email Dr Parker again

Doug

[Bjorn Jonsson]

I do not have Photoshop CS yet (which I understand has vastly improved 16 bit image support compared to earlier versions) but I think it should be trivial to import the files that have 16 bits/pixel as RAW and enter the header size when importing.

In my case this is not needed though since I am able to convert the IMG files to 16 bit PNGs.

[djellison]

In my case this is not needed though since I am able to convert the IMG files to 16 bit PNGs.

Helloooo - would you like to step into my office and tlel me how

Doug

[Bjorn Jonsson]

In my case this is not needed though since I am able to convert the IMG files to 16 bit PNGs.

Helloooo - would you like to step into my office and tlel me how

Doug

I'm using software written by myself to read the PDS stuff and do some initial processing/conversion. However, it is in a (probably permanent) state of 'not ready for release'.

However, I might be able to easily and quickly 'cannibalize' it into a standalone utility for converting IMG files to PNGs if someone is interested. However, the user interface (UI) would be crude (probably a command prompt, at least in version 1.0) since for small, quick-and-dirty utilities like this I'm usually too lazy to do a nice UI.

[djellison]

I for one would much appreciate it. Just something that'd take all the imgs in a folder and PNG them would be perfection!!!

Doug

[Bjorn Jonsson]

I made a very quick and dirty Windows command line utility that will convert PDS IMG files to PNG files, either 8 or 16 bit PNGs depending on the source data.

It's available at http://www.mmedia.is/bjj/misc/img2png.zip

It is run by opening a command prompt window and typing something like

img2png *.img

which will create PNG files from all IMG files in the directory. This might also work for more file types, e.g. Voyager and even Mariner 9/10 but I haven't tested it yet.

Please note that this is a *very* quick and dirty utility and I do not guarantee it to work at all. I have not tested it thoroughly although it seemed to work. One problem I know of is that IMGs containing floating point data (4 bytes/pixel - the 4 MB files) get converted but the result looks strange. I'll fix this later, however, I will be away from my computer for several days starting tomorrow.

Also note that the resulting PNGs will often look very dark. The reason is that 16 bits yield an intensity range of 0-65535 but in all cases I have seen the maximum intensity is roughly 3000 or lower.

[djellison]

I now pronounce you IMG god!



All thats left now really is a way to un-adjust the 'auto levels' type affair that's been done on-board

Doug

[Bjorn Jonsson]

Now that I'm back at my computer I've been considering some minor improvements to IMG2PNG if needed:

(1) Does anyone know what the files that have a size of 4 MB contain (I'm too lazy to spend a lot of time figuring it out since I suspect someone here knows). They contain floating point data that I think I have been able to read but the image I tested looks weird but recognizable. Also the data contains lots of zeros which suggests to me these are not regular images. I found these files at http://pdsimg.jpl.nasa.gov/data/mer/

(2) It's trivial to add the capability to dump the labels to separate text files if that's of interest.

(3) In a different thread someone mentioned scaling the intensity values using RADIANCE_SCALING_FACTOR and RADIANCE_OFFSET_FACTOR. Doing so is trivial but it's not something I need for my purposes. Also what I saw in that thread seemed to imply this was not needed.

(4) Any interesting ideas ?

Bjorn

[djellison]

To be honest - I dont see the need for the radiance scaling either. Then again - I dont understand the relevance now we have the fully geometric and radiance calibrated files.

The only problem I've had is that, as you said, the PNG's are so dark, that you cant really see them at first till a big tweak. So you cant browse around What would be MIGHT usefull is tiny, stretched PNG thumbnail type file to go with each IMG turned to PNG?

LIke, 256x256 maybe - something of that size. It'd make things HUGELY easier when browsing for an image set.

But - as it is - the tool is UBER usefull Many thanks for it!!

Doug