BUG - CoreImage bypasses Effect Resolution in Zoom and Print


This is a bug that I’ve been working on for two days now (and first noticed two years ago, LOL).

I’m on an older OS version (Snow Leopard Mac 10.6.8) so apologies if this has been fixed – but it’s a huge bug and I feel it’s worth an update for those of us back here on Intaglio 3.4.4 . Or maybe I’m missing something. But I don’t think so.

CoreImage is ignoring Intaglio’s Export and Effects Resolution settings both for zoom and export. That is, images changed with a CoreImage Filter (ie., Exposure) which is first added, or changed, when zoomed out (ie. 75%), will look grossly pixelated when zoomed in (ie, 200, 400, 800 percent), and will EXPORT with this pixelation (ie, to .png) even if the Resolution for the document has previously been set to High (i.e.300dpi), which gets ignored. I have found workarounds but they are difficult in some situations.

Even if Intaglio Effects/Export is set high (ie, 300dpi), and ‘preview using low res’ preference is OFF, using CoreImage means the following will happen:

  1. CoreImage makes low res screen renders when zoomed out, different at every zoom. When zooming back in these are clearly visible as poor pixelations onscreen, and are not updated — they sit there indefinitely at that resolution no matter what the zoom used. In other words, it’s when the CoreImage is created —what the zoom is then— that determines what the dpi is, not the Effects export setting.

  2. This image then exports/prints at this poorly pixelated dpi, not the Effects/Export dpi (which is what it should export/print at).

This causes havoc in a complex page with many images, if they are worked using CoreImage at different zooms. They end up as a patchwork of different digital dpi’s, and they export/print like that.

Workaround is also difficult (sometimes not perfect but good enough so far). Steps as follows:

A. Zoom in very close — ie, 400% or 800%, and toggle the Resolution preference down to Medium and back to Hi. This forces everything in the document, including CoreImage Filters, to redraw at high resolution. This should be an easy fix, except it’s not, because:

B. In a complex diagram, during this redraw., at say 800%, CoreImage will fail to redraw some images that are not onscreen — or more exactly, parts of images that are partly onscreen and partly off. They’ll be blank in parts that were outside the screen. And, they stay like this and fail to export/print --no matter what the zoom afterwards, they don’t reappear. They’re just ‘missing in action’. So, part 2 of workaround is:

C. After part A above, then zoom the offending image that is partly not redrawn, so it’s as large as possible while fully visible. Ie., fill the screen with the one image, including both the drawn and undrawn areas. Then change something in the CoreImage effect inspector. CoreImage will redraw and now everything in the image will appear. Note that this is the closest zoom (and hence best pixelation dpi) possible for this image — it might be less good than the overall document (if A. was done at 800%) but it will be usually good enough. [Unless the offending image takes a whole page and can’t be zoomed in very close. Then it’s not possible to get a good dpi at all with CoreImage (AFAIK).]

D. User should now be able to export/print the document without trouble, and these CoreImage renders will remain in the document until they’re changed — so you can fix one after another if more than one failed to fully render in part A, by using the process just described in part C for each one.

That’s it.

Any comments or hints welcome – especially from Purgatory telling me that you’re going to send an update for 3.4.4 to fix this. :wink:


Intaglio mailing list
Update your subscriptions at:

It’s not clear what you’re trying to do. Are you combining digital images with drawn shapes and text and adding effects to all of the objects? Is the document intended for the web or print and if so, is it RGB or CMYK?

Intaglio adds more ‘fuzz’ than other OSX programs. Some effects work reasonably well, but the enhancements (Color Controls and Exposure Adjust) make the image blurred and indistinct.

Preview does a good job of cleaning up images, boosting colour, cropping etc. Save as a PDF and import (PDF preserves quality). When you compare the same cleaned up image in Intaglio and Preview, Preview images tend to look slightly better than those processed in Intaglio.

This trick is crude, but it sometimes works. Scale to 200%, take a screengrab, open in Preview and scale to 50%. Any imperfections will also be reduced by that amount. This is a variation of an old pre-computer technique.

To ensure that all images are the same resolution, open them in Photoshop and specify the desired resolution in the Image dialogue box.


Intaglio mailing list
Update your subscriptions at: