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Resample image when fitting it to window

Posted: Sat Sep 11, 2010 8:10 pm
by Aeolis
Hello folks,

I have been experiencing problems using Xnview to open my manga .png files. The .png files are larger then the full screen view so they are fitted to windows size, but when Xnview does that the text written in the .png file get unreadable. I think Xnview should resample images when fitting then, so their quality would be better. Am I doing something wrong here? I could not find a option to resample images when fitting then to the windows size. Could somebody help me here? Thank you for your attention.

See you later,

Aeolis

Re: Resample image when fitting it to window

Posted: Sun Sep 12, 2010 8:46 am
by helmut
When resampling the image (zoom < 1.0, image is smaller than original), XnView will resample the image. In Tools > Options, category "View" you can select resampling quality by setting/unsetting the checkbox "Reduce" in panel "High quality Zoom". Default is high quality for reducing image's size and no high quality when enlarging.

I doubt that the above info helps, perhaps you can provide a sample image and/or a screenshot of your problem.

Re: Resample image when fitting it to window

Posted: Sun Sep 12, 2010 4:41 pm
by Aeolis
Hello folks,

Thank you for the information. Actually the information was useful. I have the options you mentioned checked. And I figured out that Xnview is applying the "antialising" when resampling in some of the .png files, but not in a few ones. Here are a few examples:

1) Xnview applies the resample "antialising" in this .png:

Image

2) But, I doesn't work as expected in this one:

Image

I hope you can help me. Thank you for your attention.

See you later,

Aeolis

Re: Resample image when fitting it to window

Posted: Sun Sep 12, 2010 6:30 pm
by XnTriq
Aeolis wrote:2) But, I doesn't work as expected in this one:

Image
Both PNGs are 8-bit paletted images, but according to TweakPNG the second one has also a trns chunk (“alpha values for palette colors, 133 entries”).
Once that trns chunk is deleted from the file, XnView applies anti-aliasing to the image.

My settings in Tools » Options...:
    • General » Operations
      • [×] Ignore alpha channel
    • View » View » High quality zoom
      • [×] Reduce

Re: Resample image when fitting it to window

Posted: Sun Sep 12, 2010 7:23 pm
by Aeolis
Hello folks,

XnTriq I have checked the options you told me, but the problem persist. Could you help me here? What do you mean by "Once that trns chunk is deleted from the file, XnView applies anti-aliasing to the image."? How can I do that?

See you later,

Aeolis

Re: Resample image when fitting it to window

Posted: Sun Sep 12, 2010 9:30 pm
by XnTriq
Aeolis wrote:How can I do that?
You'll need TweakPNG for that:

Image
Here's what I would do:
  1. Batch convert the PNGs to 24-bit color depth with XnView
    to get rid of the (unnecessary?) transparency.
  2. Batch process all converted PNGs with PngOptimizer
    to automatically reduce the filesize without sacrificing quality.
Related topics:

Re: Resample image when fitting it to window

Posted: Sun Sep 12, 2010 9:59 pm
by Aeolis
Hello folks,

Thank you all for your support.

See you later,

Aeolis

Re: Resample image when fitting it to window

Posted: Wed Sep 15, 2010 6:19 pm
by helmut
Obviously the hints helped. Excellent links and support, XnTriq! :-)