Resolution drop from 300dpi to 150dpi after Patching

Q&A about the latest versions
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riefa
Posts: 9
Joined: Wed Nov 04, 2009 12:15 pm

Mon May 02, 2011 3:58 am

Hi all,

I have a 14000x7000 equirectangular and use Pano2VR Patch tool to correct and/or remove some unwanted items (nadir, shadows, etc.).

After Patching, I re-output the equirectangular, but when I check at Photoshop (Cmd+Alt+I) the resolution dropped from 300pixels/inch to 150pixels/inch, and also width & height at Document Size section (i attached some screen shots)

Anyone know what settings do I need to set on Pano2VR so the pixels stays unchanged?

Thanks..:)
Attachments
after patching
after patching
150pixels.png (83.14 KiB) Viewed 2666 times
before patching
before patching
300pixels.png (82.12 KiB) Viewed 2666 times
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Roy Reed
Posts: 164
Joined: Thu Apr 19, 2007 10:31 am
Location: London, UK
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Mon May 02, 2011 6:03 pm

Nothing that matters has changed. The pixel dimensions before and after are both 14000x7000. It would only matter if you printed the file at the indicated DPI.
riefa
Posts: 9
Joined: Wed Nov 04, 2009 12:15 pm

Mon May 02, 2011 7:10 pm

ah i c...thx for the reply Roy.

so, if I manually change from 150dpi to 300dpi (and in respect of that, i also have to manually change the pixel dimension to 14000px x 7000px and also the document size to 118.53cm x 59.27cm), does the pixels actually gone thru another proces, which might degrade image quality for online/web viewing?
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alabwab
Posts: 21
Joined: Thu Nov 25, 2010 3:43 pm
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Tue May 03, 2011 11:14 am

Hi,

Your example shows that changing the document size (dpi-value) will not affect the pixel dimensions of your image.

document size - refers to the size of the image in print output
changing dpi affects the print output of the image (the size of the image is determined by the dpi value)

the numbers in the "pixel dimensions" field tell you how many pixels (of detail) your image has. when you reduce the width and the heigth in this field you will loose detail.

When you present an image on a webpage you either scale the image (for example in photoshop) to the desired format before loading it up on the server. Or you load up the original image in its original pixel dimensions and scale it in the browser by using html code. Clearly the second solution has many disadvantages. (much more time for loading and scaling the image is needed)
riefa
Posts: 9
Joined: Wed Nov 04, 2009 12:15 pm

Tue May 03, 2011 11:31 am

Hi alabwab,

Really appreciate the explanation. I think i understand it better now..:)

Thank you all for helping me out.
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