2 bugs with images

[0xDEADC0DE]

I have 2 bugs with the current version of PDF-XChange Editor.

First:
Enable the content pane and look up an image in a pdf. There you have the same width and height as in the properties pane.
But when you export the image (Save Image As), the size increases by one pixel in width and height and the image is blurry.

Second:
By default, the "Smooth Images" setting is enabled. This setting should only be used on images which needs to be resized.
If you have a screenshot with text which is pixel perfect in a pdf, it looks blurry. But it's unnecessary.

Thanks for your feedback
Marc

[Sasha - Tracker Dev Team]

Hello Marc,

Well the image itself can be in a XForm for example and can be clipped, so that the visual representation is a pixel less. Also, the original image in the PDF structure can differ from the image that you see on the screen.
Anyways, if you wan't us to tell more, please attach the file sample, or you can mail it to me directly at polaringu@tracker-software.com

Cheers,
Alex

[0xDEADC0DE]

We use pdflatex to create the pdf.
From the logs, the png is directly included and not converted.
I have included the png and the pdf.
Try to export the png inside the pdf and compare them.
Also why is the image blurry?

[Timur Born]

The image likely is blurry because Editor applies its smoothing to copy and export operations. You first have to disable smoothing (which luckily was fixed) before you export images, at it worked that way last time I checked (quite long ago).

[0xDEADC0DE]

But why is smoothing used if the image is not resized?
It's a bug for me and the image looks blurry.

[Timur Born]

I turn smoothing off for images, especially since Editor's smoothing is stronger compared to Adobe's.

[Tracker Supp-Stefan]

Hello 0xDEADC0DE,

It is very unlikely that an image will not be 'resized' when it is inside the page of a PDF file that you look on screen.
First you have the PDF page dimension that is defined in millimeters (or inches), and then you have to display that on a fixed number of pixels. There will usually be some rounding.
Then the image is usually not the whole page but only part of it and it's dimension in pixels are such that those pixels can not be matched 1:1 to the pixels on your screen at all but at a very specific zoom level (which is more than certain not at 100% zoom). Screens are normally ~96 DPI, or with more recent screens - even higher. My screen is with e.g. 111.54 DPI resolution - and trying to display on it pixel for pixel an image that is embedded in a PDF file at 300 DPI will mean that a zoom of 268.96% will need to be used for the PDF file - even at 268 or 269% zoom - I will not have a perfect match between the pixels inside the image and the pixels on my monitor. That is why some image smoothing is normally needed. Admittedly for high quality text with high enough DPI this might have negative effect, but it is necessary in other scenarios, and as most of the time it is beneficial to have this setting on - it is turned ON by default.

Regards,
Stefan

[Timur Born]

While I agree with display smoothing being beneficial, it should not happen when images are exported/saved at their native resolution. I don't know if this was fixed meanwhile, but it did happen in the past.

[Vasyl-Tracker Dev Team]

Hi All.

In the Editor you already have a possibility to export original images, without any viewing transformations like scaling, rotating etc. (an special viewing-transformation is always applied when any image is displayed on pdf-page) .
To do it you need to turn on one option in context menu for the selected image:

and then just use the 'Save Image As' feature below in that menu.

When you using our PDF-Tools you may do the same with turned off the "Actual image view" option:

Also note: the option 'Preferences/PageDisplay/Rendering/SmoothImages' - it just option for displaying/rendering, it does not take effect on the adding/extraction of images.

HTH.