Heavy compression artifacts when creating a flat gigapixel panorama (solved)

Hi all,

on my last vacation in Portugal I took a 3 gigapixel panorama

Everything looks wonderful in Photoshop, including the sky.

The image has a size of almost exactly 3 gigapixels, 113,104 x 26,553 pixels. Due to the size, the file also has 27.5 GB and I had to load the image directly from the .psb format with the krpano tools v1.21 using the flat.config.

Now I have very strong compression artifacts in the sky that don't exist in the original Photoshop file. Can I do anything about it? I'm a little at a loss right now.

Here's a link to the file, please look at the sky, it looks very bad.

Ferragudo

And here is the XML code if you need it.

<krpano bgcolor="0x000000">

	<!-- the skin and the flat pano viewing and controlling setup -->
	<!--<include url="skin/defaultskin.xml" />-->
	<include url="skin/flatpano_setup.xml" />
	
	<!-- preview pano image -->
	<preview url="Ferragudo.tiles/preview.jpg" />

	<!-- pano image -->
	<image hfov="1.00" vfov="0.234766" voffset="0.00">
		<flat url="Ferragudo.tiles/l%l/%00v/l%l_%00v_%00h.jpg" multires="512,1792x422,3584x842,7168x1684,14080x3306,28288x6642,56576x13284,113152x26564" />
	</image>
	
	 <!-- link wnlpd.com -->    
        <plugin name="logo" url="logo.png" zorder="0" alpha="0.7" scale="0.5" onover="tween(alpha,1.0 ,0.6);" onout="tween(alpha,0.5 ,1);" onclick="openurl(https://www.wnlpd.com/galerie/tour,_blank);" keep="true" align="rightbottom" x="20" y="30" />

</krpano>

Thank you!

Many thanks Klaus,

yes, you're right, that's color banding, unfortunately I said it wrong, sorry.

It's of course a 16bit file, I'll try to see if it works, output the file to 8 bit in Photoshop and only then continue working with the KR Panotools.

Thank you also for the tip about the color profile, if the colors on the internet differ a little, I honestly don't care. I work on a calibrated monitor, but what do I know what the rest of the world has or how they see my photos. The colors are important to me for prints, but for the internet it's not really extremely relevant. (my opinion!)

I find the JPG quality really amazing! Is there actually anything that krpano can't do?

Ich wünsche Dir ein frohes neues, und ich hoffe Du bist gut rüber gerutscht! (happy new Year!)

I have now edited the whole file again, starting with the raw data.

Obviously I made a mistake somewhere in the image processing, with the new version I can load both the 16bit and 8 bit version into the KRpanoTools without banding.

Many thanks for the help Klaus, I have learnt a lot again!
I didn't even know about the options in the "flat.config!

Now everything looks fine, I'm really happy!