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Question

Artifacts and lines distortions in exported images

Forum|Forum|2 years ago
February 12, 2024
4 replies
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I have seen that others have reported similar issues... I am experiencing a very annoying error in InDesign (v 16.0 but also newer versions):

When I insert images and then export them in jpg or png format, even in very high resolution, artifacts and distortions occur, especially when there are thin, slanted, or straight lines...

It is very frustrating because I often have to export some graphics and layouts in different sizes through InDesign to print in quality. However, every time I export, these horrible errors occur. It is definitely a bug, similar to what I have experienced on older versions (Mojave and InDesign v16), but also on the latest versions on Mac Studio with Sonoma. I have already tried resetting preferences and disabling GPU performance, but to no avail... I am attaching examples of the distorted exported images. Thanks to everyone.

PS: as requested I also attach original undistorted images and export to PDF (undistorted)

TEST-distorted-lines-INDESIGN.pdf

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reproo2773183

Inspiring

I'm not sure this is a bug.

this image shows your lines are only 2 or 3 pixels.

300ppi is not enough.

When you ask InDesign to write a Jpeg and Downsample you have no control over how it does this.

In Photoshop you have 7 different options for re-sampling, to get the best result is image dependant. You also get to resample before you Jpeg, with InDesign it could be doing it the other way around.

Rob Day points out that with your image its the downsampling that is doing the most damage.

Thin Lines that are regularly spaced need to be rastered, ideally with the spacing being a whole number divisible by the output resolution, otherwise the lines will be different number of pixels thick, (some will get rounded up some will get rounded down). You can get away with this if the difference is say between 9 or 10 RIPped dots, and anti-aliasing will help but when you only have 2 or 3 RIPped dots its impossible.

I would make 2 suggestions:

1 don't downsample until you have to.

2 choose a higher res than 300dpi, this sort of image you'll see a positive difference at 600dpi, you may see the difference at 1200dpi but probably not on an inkjet or toner digital device.

Every Year we print a catalogue for wood engravings, I recommend 600ppi and ZIP compression for their images, they often Moiré on screen but always print nicely.

One last tip is that if you rotate an image in InDesign then make a pdf the pixels remain intact, the rotation is non-destructive. If you RIP the pdf or open in Photoshop its at that point it becomes destructive, extra resolution in the pdf will help, compared to InDesign's Export to Jpeg which has to be destructive.

rob day

Community Expert

Hi @reproo2773183 , The artifacts in @Gamm System ’s file are happening only on an export downsample, and do not appear on a Photoshop downsample from a higher resolution. They also are not happening through out the images—most all of the image downsamples as expected.

Here is the InDesign page exported to a PDF with compression turned off and imported into Photoshop via Import PDF at 150ppi on the right, and the same page imported into Photoshop at 1400ppi and downsampled to 150ppi via Image Size on the left. The artifact on the right is much more than a few errant pixels. I’ve attached the PDF

TEST-distorted-lines-INDESIGN.pdf

rob day

Community Expert

Hi @Gamm System , I’m not sure if this helps, but if I force a downsample on the PDF Export rather than letting it happen when the PDF is imported into Photoshop, the artifacts are not there. So here the version on the right with the artifacts is from a PDF Export where I’ve turned off downsampling and compression, and the version on the left is from a PDF Export where I forced everything to downsample to 300ppi on the Export, before I import the PDF into Photoshop:

JR Boulay

Community Expert

The JPEG compression algorithm necessarily degrades the image, even at higher quality, and is particularly unsuitable for this type of image (fine lines).
Always prefer TIFF or PNG (non-destructive), but make sure you use 24-bit PNG (vs. 8-bit/256-color).

Acrobate du PDF, InDesigner et Photoshopographe

Luke Jennings3

Community Expert

You might try exporting a pdf from InDesign, then opening the pdf in Acrobat and exporting all pages as images, where you can control the image type, compression and resolution. The distortions look like stitching lines to me which typically appear after flattening transparency but might also be caused by compression or re-sampling. You might also try using an Acrobat preflight profile to convert the pdf page content to an image. (duplicate the existing profile to edit the settings)

G

Gamm SystemAuthor

Known Participant

Hi Luke, honestly, I hadn't thought about the step with Acrobat; I used to create the PDF and export pages from Photoshop. However, indeed, using Acrobat might be better...

It's not so much the compression artifacts that bother and worry me, as they are always present in JPGs, but it's that the lines appear 'cut/broken' and 'shifted' in several places. I think it happens even with simpler shapes like rotated rectangles, not just on thin and dense lines... I believe there are similar posts in the community; maybe I'll run a test.
Thanks a lot.

JR Boulay

Community Expert

(created and exported from Adobe Illustrator as PNG 300dpi).

I think the error comes from this process, if you have vector images you need to keep them in vector when importing into InDesign. In other words, you need to import them in Ai or PDF format.

It is very frustrating because I often have to export some graphics and layouts in different sizes through InDesign to print in quality

Vector images are independent of size and resolution, and remain sharp in all cases.

Acrobate du PDF, InDesigner et Photoshopographe

G

Gamm SystemAuthor

Known Participant

Hi JR, thank you, but I'm well aware that vector images don't get distorted... in fact, whenever and wherever possible, I use vectors instead of raster images. However, these are just simple lines, only sample images, generated in Illustrator and specifically exported in PNG and JPG to better understand the export issue in InDesign... The actual original images are much more complex and were created in Photoshop by blending various techniques and elements; I can't use them as vector images. In any case, the problem remains with raster images in InDesign when exported as final JPG or PNG files.
Thanks.

leo.r

Community Expert

Does it happen if you export to PDF?

Also, how do those images look originally without distortion (I think you only posted distorted versions)?

G

Gamm SystemAuthor

Known Participant

Hi, sorry, I didn't attach the originals, obviously not distorted (created and exported from Adobe Illustrator as PNG 300dpi).

The export to PDF seems better, not distorted... in fact, the problem is with exporting images to JPG and PNG.

I have now attached the originals and the exported PDF (see original post) . Thank you very much.

leo.r

Community Expert

Frankly, I don't know why they get distorted (maybe other users will chime in).

But if PDFs are fine then maybe just export to PDF, then convert them to images (if you have to use images as the final format). You can rasterize PDFs in Photoshop (or other simpler tools) and this process can be automated, if needed.

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