Scaling from 300 to 200 dpi?

Ask for help and post your question on how to use XnView Classic.

Moderators: XnTriq, xnview

Post Reply
barsk
Posts: 4
Joined: Wed Jun 13, 2007 10:51 am

Scaling from 300 to 200 dpi?

Post by barsk » Wed Jun 13, 2007 11:56 am

How to properly scale an image in xnview from 300 to 200 dpi?
The change DPI function only changed metadata.
The change picture size function does not take decimals in the percentage scale parameter. I need to specify 66.66666%. 67% is close, but differs to some degree.

Is there another way to do this properly?

The images I need to convert differs sligthly in size so a direct width/height setting is not sufficient either.

User avatar
Drahken
Posts: 884
Joined: Sun Apr 10, 2005 4:29 pm

Post by Drahken » Wed Jun 13, 2007 3:54 pm

The image->set DPI setting DOES change the DPI of the image, it's just not apparent right away because of the fact that image viewers display images at their resolution, not their DPI. Xnview has recently added an option to view the image based on it's DPI however, this is located at view->real size. To see that the DPI of the image does indeed change, set it to a high DPI and click the real size option. Now set it to a low DPI and click the real size option again.


The only available options for resizing are percentage & dimensions. This means that you're only options are 67% or specifying a size. When batch resizing, you can simply set the size for one dimension, and it'll automatically set the other dimension for each image. Thus, if the proportions vary from one image to the next, you could have them all say 1200px in height, then let the width vary appropriately.

barsk
Posts: 4
Joined: Wed Jun 13, 2007 10:51 am

Post by barsk » Mon Jun 18, 2007 3:08 pm

Drahken wrote:The image->set DPI setting DOES change the DPI of the image, it's just not apparent right away because of the fact that image viewers display images at their resolution, not their DPI. Xnview has recently added an option to view the image based on it's DPI however, this is located at view->real size. To see that the DPI of the image does indeed change, set it to a high DPI and click the real size option. Now set it to a low DPI and click the real size option again.


The only available options for resizing are percentage & dimensions. This means that you're only options are 67% or specifying a size. When batch resizing, you can simply set the size for one dimension, and it'll automatically set the other dimension for each image. Thus, if the proportions vary from one image to the next, you could have them all say 1200px in height, then let the width vary appropriately.
Hello, sorry this is simply not good enough for me. I need to scale all images proportionally, regardless of orginal resolution to 66.66666% size, and change DPI setting from 300 to 200. 67% is not close enough IMHO, besides xnview also cannot preserve an exact file tree hierachy in batch so there is two "flaws" that prevent me from doing what I need with this tool.

Otherwise XNView is really nice!

David.P
Posts: 14
Joined: Wed May 02, 2007 9:26 am

Re:

Post by David.P » Sun Dec 08, 2019 2:26 pm

Drahken wrote:
Wed Jun 13, 2007 3:54 pm
The image->set DPI setting DOES change the DPI of the image
Just wanted to add here that this approach unfortunately recompresses the JPEG image and therefore is not lossles

cday
XnThusiast
Posts: 2276
Joined: Sun Apr 29, 2012 9:45 am
Location: Cheltenham, U.K.

Re: Re:

Post by cday » Sun Dec 08, 2019 6:37 pm

David.P wrote:
Sun Dec 08, 2019 2:26 pm
Drahken wrote:
Wed Jun 13, 2007 3:54 pm
The image->set DPI setting DOES change the DPI of the image
Just wanted to add here that this approach unfortunately recompresses the JPEG image and therefore is not lossles
Have you searched online?

The following link lossless change of dpi of a jpeg photo indicates that the DPI of a JPEG can, at least in some circumstances, be changed without recompressing the image.

The are other results that I haven't studied from my search "change dpi without recompressing'.

David.P
Posts: 14
Joined: Wed May 02, 2007 9:26 am

Re: Scaling from 300 to 200 dpi?

Post by David.P » Sun Dec 08, 2019 9:26 pm

Yes, thanks. Have searched online ad nauseam...

With IrfanView and XnView (both Classic and MP), it didn't work at all. With Faststone Image Viewer and with ExiftoolGui, it (strangely) worked on some JPG images, but not on some others.

Post Reply