Image with transparency, jagged shadow

[sPretzel]

Hello,

I've stumbled upon a strange behaviour in AI that I don't understand. I've placed a TIF image with transparency in AI (supposedly, it has no layers to it). When I add a drop shadow to the image, the drop shadow is slightly jagged. If I embed the same TIF image and add the drop shadow (Flatten Layers to a Single Image option for TIFF Import Options), the drop shadow looks correct and follows the contour of the image.

What is the jagged drop shadow due to? Is there a way to get the correct behaviour without embedding the image?

This is for CS4.

Thanks.

[Monika Gause]

Can we perhaps see a screenshot?

Also: which system is it?

[sPretzel]

Hello Monika,

I have attached a screenshot. Let me explain. The orange bit is the image. The black portion is the shadow of the image. The green background is colour behind the image (the image has transparency).

1- The top image is embedded TIF in AI and shows fairly straight shadow. This is what I expect.

2- The bottom image is the placed TIF in AI and shows jagged shadow. I see two ripples in the shadow (they are also visible in the embedded image but are much less pronounced).

The system in Windows Vista.

[Kurt Gold]

You .tif file does not represent a proper rectangle. Therefore, I'd say the ripples are normal (there are more than just two).

I also see the difference, but it could be helpful if you were providing the .tif files, so one can take a look.

Is there any reason why you do not just draw the brown rectangles/lines in Illustrator?

[sPretzel]

Hi Kurt.

The orange bit is not a (vector) rectangle. It's a picture that I cropped. That's why I can't just draw the lines in Illustrator. The two ripples, as pronounced as they are in the placed TIF, are not "normal". If I use the TIF file in Photoshop and create shadows in Photoshop, I don't see the ripples. The embedded TIF in Illustrator looks much more "normal" to me.

[Kurt Gold]

May I ask you again if you can share the .tif file (via Google Drive or similar providers)?

[sPretzel]

Hi Kurt. Sorry, I haven't been able to make a version I can upload. I guess you might be able to reproduce the problem by making an image with transparency. I should add that the jagged lines become worse when rotating the image!

There is another thread here which points to "anti-alias" in Raster Effects Settings. It didn't work for me, unfortunately.

Drop shadows and blur is pixelated on Illustrator CC

[Kurt Gold]

Honestly, I cannot imagine a reason why you could not share the file. Is that brown line protected by some copyrights?

However, considering the slightly irregular edges shown in your screenshot, I still say that the ripples seem to be normal. I see the difference between the linked and the embedded version, but I would have to take a look at the original .tif file in order to help you.

[sPretzel]

Hi Kurt.

I tried with a png version and I get the same result. The jaggedness is more apparent when rotated in AI. This is an image comparing the two:

1- Top part is embedded png with drop shadow and rotation (rotation is in a layer above drop shadow in AI).

2- Bottom part is placed png with same drop shadow and rotation.

The second image is the bare png file (no rotation and no drop shadow applied).

[sPretzel]

Hi Kurt. Any luck on your end? Thanks.

[sPretzel]

Any insight? Anyone managed to reproduce the problem? Thanks.

[Ray Yorkshire]

Not sure if its in the same place in CS4 but try

Effect > Document Raster Effects Settings

And change Resolution to a different level.

[sPretzel]

Hi Ray. It's not related to Raster Effects Settings. The two images in my previous post have the same setting. Still, I tried your suggestion anyway with a higher resolution: the problem remains.

[fredrikm63101779]

Hi.
Did you find the solution of this? I am having the same issue and the only way I found is to make the image included in the Illustrator-file, but I would like it to be linked. Happens with tif, png, psd both RGB and CMYK. As soon as the linked image is included instead, the quality of the shadow is perfect.