• Adobe Photoshop

  Scaling down

  Posted by Martin Sterling on February 19, 2008 at 1:27 am

  I can’t figure out why everytime scale down a large jpg picture the image falls apart at a certain point. How do I fix that?

  Thank You in Advance

  Adolf Witzeling replied 18 years, 2 months ago 4 Members · 3 Replies
• 3 Replies

• 

  Richard Harrington

  February 19, 2008 at 2:30 am

  Need to be more specific

  But scaling is throwing away information.. at some point you don’t have enough pixels to describe the image.

  Richard M. Harrington, PMP

  Author: Photoshop for Video, Understanding Adobe Photoshop, and ATS:iWork
• 

  Darby Edelen

  February 19, 2008 at 6:05 am

  You can achieve slightly better results when scaling if you do it iteratively, instead of scaling down to 50% try scaling down to 95% 13 or 14 times. This won’t work miracles because, as Richard said, every time you scale down you’re throwing away information.

  Darby Edelen
  Designer
  Left Coast Digital
  Santa Cruz, CA
• 

  Adolf Witzeling

  February 21, 2008 at 11:06 pm

  Hello friends at the cow!

  Please allow me to throw in my 2 cents worth.

  First of all, I believe the reason why your picture is falling apart, when you downscale is the fact that you are using the JPG format. JPG is probably the worst format in the world ( sometimes I like to exaggerate), because every time you open it, do something to it, then save it, it averages the colours it contains. That means it chooses similar colours and reduces it to one average colour.
  So you are loosing colours every time you save. That’s also known as posterisation.

  Also I don’t agree 100% that when you downscale you loose all the pixel information.
  The correct way in my opinion is in PS in the image size dialog, to uncheck the RESAMPLE IMAGE button, but make sure the KEEP PRPORTIONS button is checked.
  This way when you downscale, you don’t loose pixel info because if you go down in size, the resolution will go up, so it’s still contained in the picture.
  If you downscale withe the RESAMPLE BUTTON checked, you will loose information, because the image resolution stays but the picture get’s smaller. Does that makes sense?

  A good idea when downscaling is to at the very end apply some unsharp masking ( depending on the reduction factor I would start with something like: 150, 1-1.3 pixel.

  The most important although is that you first, right after opening the document, save it as an PS or TIFF or such, but not JPG.

  Give it a shot, I bet you will be surprised about the differnt result.

  Hope that helps,
  Adi

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