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edk

macrumors regular
Original poster
Apr 12, 2006
112
0
Hi, I have a batch of photos (each around 7MB) that I need to reduce to around 1MB in size each.

Is there a way to do this, without much visible quality loss? Someone mentioned to me that you can reduce the color depth, and it has no visible effect.

Any tips on how to best do this via photoshop/bridge/picassa, would be greatly appreciated!!
 

rolsskk

macrumors 6502
Sep 1, 2008
300
297
Why do you need to shrink the file size? Why not just resize the image if you need to shrink the file size. There's no way that you can magically drop 6mb off each image without impacting the quality of it.
 

edk

macrumors regular
Original poster
Apr 12, 2006
112
0
I have to share a batch of photos to a parents group via the school. However, the school uses a very very old ISP account with very little space available.

(And that's another topic for another day... I'd move them to Flickr if it had a built in download set option... unfortunately it doesn't :( )

So, rather than uploading 500MB+ of photos, it needs to be more around 150MB.

The guy who did this before mentioned the 'reducing colour depth' as a way of keeping the files large and usable, while keeping quality. 'it just removes the unused data' was his comments.... and the old photos on the server are all around 800KB and look not too bad.

Problem is... i've not be able to work out how to do that yet :) (edit: and the guy isn't around to ask at the moment)
 

NeGRit0

macrumors 6502a
Apr 19, 2008
941
185
Las Vegas, Nv
I have to share a batch of photos to a parents group via the school. However, the school uses a very very old ISP account with very little space available.

(And that's another topic for another day... I'd move them to Flickr if it had a built in download set option... unfortunately it doesn't :( )

Why not upload to dropbox, and share that way?

The guy who did this before mentioned the 'reducing colour depth' as a way of keeping the files large and usable, while keeping quality. 'it just removes the unused data' was his comments.... and the old photos on the server are all around 800KB and look not too bad.

Problem is... i've not be able to work out how to do that yet :) (edit: and the guy isn't around to ask at the moment)

Have you opened one of the old files to check the actual image size/resolution of them? He may have sized them down, especially if these are just for web viewing.
 

Laird Knox

macrumors 68000
Jun 18, 2010
1,956
1,343
What are the images going to be used for? Print, web, billboards?

If Photoshop check Image > Mode and see if they are set above 8 Bits/Channel. 8-bit should be fine.

How are you saving the files? If they are TIFFs then switch to JPEG. A reasonable setting on the JPEG quality (8 - high) should be good for most uses.

If they are just web bound reduce the longest side to no more than 1000 pixels.

Once you know what you want to do to the files record an action and batch process the files.
 

compuwar

macrumors 601
Oct 5, 2006
4,717
2
Northern/Central VA
It depends on what format the images are in, what resolution they're shot at and what the output medium is. In general, the answer is yes, unless you're pixel peeping you can generally go to JPEG at a quality of 7-8 and re-size to fit your output just fine.

Paul
 
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