Why am I having errors when importing images with over 8,388,608 pixels?

[benjaminp1952888]

Here's a puzzling one for you all...

Background

I've been using InDesign for a long time, since my days as a print designer, and have been fortunate to see it evolve into a pretty solid tool for digital design too. Having tried (and loved) a host of other programmes for web design (Illustrator, Sketch, Axure to name just a few) I do find myself returning often to InDesign for all forms of digital design, primarily because of it's superior powers when it comes to controlling type. This means that I'll often drag a JPG, PNG, or PSD into InDesign as a background, starting point, or reference when creating new pages and designs.

Problem

Bizarrely, I've noticed recently that when I place some images into InDesign (as a linked file of course) they seem to pixelate.

I know what every one of you with any sense is thinking right now – "doofus, just change the display settings to High Quality rendering and end this thread..." Please read on my friends...

Here's the difference between this thread and most of the others along a similar topic on this forum – My problem isn't only with the display of images – they actually render with the same pixelation/distortion when exported as a PNG.

Further investigation

Naturally I racked my brains about this one all morning trying to see which images were affected and which remained pixel-perfect. That's where it got interesting.

It became clear early on that it was nothing to do with colour profile, pixel density, file size or display settings 😜 and that it was, in fact, related to image size. Having played around for some time with what feels like a thousand different image sizes, I've refined down my problem pixel region to a single pixel tipping point, beyond which images no longer render or export properly.

That magic value appears to be 8,388,608 pixels. Any image with a total number of pixels at or below this value renders in full pixel perfection. For example, an image with a width of 2474px and a height of 3390px (8,386,860px in total) renders perfectly well. Increase the height or width by a single pixel, and everything goes Pete Tong.

The Question

My Question is WHY... Why this restriction? Why the bizarre rendering? Why the lack of prompt from InDesign to inform me that everything is about to look rubbish? And why 8,388,608. I understand that it's a bit of a special number (I know it's the first power of 2 in Bits that is above 1Megabyte) but why should this affect the way InDesign deals with the image?

Any answers would be massively appreciated. And Adobe, any chance you could change this in future versions?

[rob day]

The quality of linked images in JPEG and PNG exports has always been problematic. I think you'll see that InDesign objects don't pixelate–the problem is only with placed objects. The solution is to export as a PDF, open in Photoshop, and save as PNG or JPEG there.

See this thread. #16 has an AppleScript for exports to JPEG via PDF.

Re: BUG: Indesign CC 2014 - significant image artifacts with 'export as JPG'

[benjaminp1952888]

Thanks for getting back so quickly with an answer. I've glanced through the thread and agree it's likely the same issue. It's strange though that no one else seems to be calling out that there's a pixel limit or what that limit is.

Do you have any idea just why the limit is in place and why it's set at such a specific pixel volume?

Thanks for the script – I've given it a go and it's an amazing workaround – kudos (assuming you wrote it?) While I'd be happy to export to export using a script like this, the one you've provided isn't quite going to work for me unfortunately. First it only allows single page exports – I'm designing sites with dozens of pages and states, each of which need to be exported individually with this script.

Second, it doesn't allow PNG exports, which I'd prefer in order to avoid all those JPG artifacts that can creep in.

It seems a huge shame that you/someone has to take time out to build a script as a workaround for something that seems more like a bug on Adobe's part.

Thanks so much for your help on this.

[rob day]

I'm designing sites with dozens of pages and states, each of which need to be exported individually with this script.

Are the PNGs you are exporting going directly to the server or are you assembling the states in Photoshop? If the latter you can export the entire document to PDF and place the pages in Photoshop layers.

[benjaminp1952888]

Not sure if this answers your question, but my current workflow is to export the whole document as separate PNGs into a local folder, then drag those flat PNGs into InVision to create an interactive prototype.

[rob day]

AcrobatProDC has a Image Export that would let you export all of a document's pages to PNG. I haven't checked the quality, but you could export your entire document to PDF/X-4 and try it out. The tool icon gives you some export controls including resolution. so if you wanted  4000x2000 pixel PNGs, set your ID document up to 4000x2000 pixels and export as 72ppi: