P: PDF import show edge artifacts on tiled PDF images (bug in PDF creation)

That just looks like JPEG compression artifacts.
And no, we haven't seen problems with non tiled images in PDF or EPS.

CS6 did render images with slightly lower quality than CC (due to an issue in the rasterization engine).

Hello Chris,

this is what I mean. It seems like a non-tiled image is also rendered wrong in PS CS6+. The artifacts look like a clipping error that appears on a plain image with no transparency flattening or effects rendered from PDF without depending on production software. Please see the following image – download it and zoom in at 400%.


You will see three horizontal edges running all over the image. You can recognize them best in the darker areas. These lines are not present in the original image or in PS CS5 renderings of the PDF file. And they are not about the well known white lines from tiled images. But I think it ́s about the same reason why they do appear.

Are you really sure this is not about a wrong-algorithm-caused rendering bug of the new engine?

Can you – or anybody else – confirm my rendering results?

Best regards,

Jan

The new antialiasing works much better and faster than the old antialiasing. But it shows the problem with tiled images more clearly than the old antialiasing (which still showed problems with tiled images). So the new antialiasing is a huge improvement, but we still need to fix the creation of those tiled images in PDF files.

if you select one of the tiles, yes they are quite visible.

The lines are due to the tiles in the PDF file, which only happens for some PDFs that have transparency flattened. This is dependent on the application that produces the PDF file.

Hello Chris,

I ́ve got a technical question. Are the tiles of tiled images visible when the PDF file is reopened in Illustrator?

It ́s because the images in my previous post are not tiled when the PDF files are opened in Illustrator. The rendered image shows artifacts wich seem like a line-offset. As described in my post this behavior is not depending on the program wich produces the PDF file.

So it seems that I and most of the other guys here are using another photoshop CS5 than you do... ^^

If the "better" rendering does worse work than the "old and bad" rendering, something is going very wrong.

Also, I have the bug reports about lines appearing in rasterized PDF from Photoshop CS2, CS3, CS4 and CS5.

Because I've seen the artifacts in the old versions and current versions, researched why it happened, and talked to several experts about why it happened and can't be avoided with the tiled images.

Btw... why you dont trust us? everyone is telling you that the old code worked fine for rasterizing pdf's, but you dont believe us...

I want to see this lines in cs5 also by myself. please provide your pdf that causes this error. i am sure you will not do... because there are no lines in cs5