Hubble Orion Nebula Image Deriviative

[thorpie]

Hello
I was hoping someone could advise what has caused color banding on a manipulated hubble image of the Orion Nebula.
The manipulation undertaken has been to convert the image to a pipapic. A pipapic uses all of the 16,777,216 colors from the rgb color-space each for a single pixel on a canvas of 16,777,216 pixels. So every color from the rgb color-space is used and every pixel in the image is a unique color.
Existing images can be converted to pipapics by various sorting and allocation mechanisms. The conversion undertaken on the Hubble image of Orion Nebula has produced banded swathes of similar color that are not visibly differentiated in the original image.

I presume this banding is caused by some underlying trend in the original, and that this trend is something like a red shift that possibly differentiates the velocities of matter in particular areas.
Would anybody know what is causing this banding?
Original image is at http://www.pipapic.org/images/orionoriginal.png (36 Mb)
Pipapic image is at http://www.pipapic.org/images/orionpipapic.png(31 Mb)
Please note that the image used is a 4096 *4096 pixel area of the 6000 * 6000 pixel image downloaded from http://imgsrc.hubblesite.org/hu/db/images/hs-2006-01-a-hires_tif.tif
For anyone interested I have also pipapiced an image of the sun, http://www.pipapic.org/images/sunpipapic.png (25 Mb)

 

[michaelmozina]

I have no experience at all with the pipapic image processing technique, but at first glance the color scheme of the processed image does seem to follow many of the color patterns in the original images, including the solar image (which I assume is the original SDO composite image). Could you be specific about what you thought would be different in the processed image and why you expected it to be different? That might help me understand a little bit about the processing technique you are using.

 

[UFmbutler]

I also have no idea what pipapic is. However, you should note that images like the one you're manipulating are the result of combining images from multiple bands. Each band is then mapped to a color (usually the longest band is chosen as red, shortest as blue). What you are probably picking up is different components of the gas that appears in different bands but not in others, so is predominantly a certain color. This can have something to do with redshift I guess, but considering the Orion nebula gas is mostly at the same distance from us - and therefore, roughly the same redshift, it is more likely to be caused by the spectrum of the gas (i.e. its color).

In any case, RGB images are not used for science purposes and are almost solely just for presentation. If you want to determine anything meaningful you need to look at it in individual bands.

 

[thorpie]

Thanks for responding
I really had no idea what I expected when I converted the image. It is the first large image I have processed (it took 26 hours for the conversion to complete) and it is the first image of astronomic matter that I have undertaken. On first view I was disappointed because all of the wispy detail has disappeared.
However when reviewing it later I thought it odd that in the image you get the impression that two masses have been ejected from the white centre (the blob at the top left and the smaller bright red mess covering the white) and that the bands of magenta then blue then cyan look like stress indicators from stretching the area around the white hole. Or it may be gravitational effects with the gases being separated by attraction to the massive separate blob in the top left. Whatever, it does appear to show something not as noticible in the original.
Pipapics force images to display the the broadest range of color possible, and force the contrast inherent in displaying this broad range of color. Whether this has any use I do not know, I just thunk it up and thought I should have a look see coz no-one else has, that I know of.
I was actually mistaken, this is a smaller pipapic of an astronomic subject that I have previously converted.