Tuesday, December 6, 2016

resolution - Illustrator giving two values for ppi for a linked raster image, only when rotated?


I am trying to place this raster logo supplied by a client on a large format template (this being a raster logo of some text in Arial is a separate issue).


In Photoshop, the image is showing at 200ppi at original size (third image).


When placed on our Illustrator template, and scaled up to a reasonable size, the image is 85ppi, as shown in the top left corner (second image).


When I rotate this image to fit on the template more appropriately, the resolution seems to change to a multi-dimensional value of 379x19ppi!?


I assumed that this was some sort of horizontal and vertical representation of pixel density, and using pythagoras theorem figured that the square root of 379x19 is approximately 85ppi.



However, does this mean that the pixel density of the image is now somehow inconsistent across its' length and width? Or is this just an inefficiency of using Ai to manipulate raster imagery? At a glance, 379x19 does not represent the actual dimensions of the image either which is about 50x10cm before scaling.


Does anyone have any explanation for this? I have googled this to death and not even found one acknowledgement of multiple values for resolution! I can find plenty of ways round this for the purpose of this job, but it's extremely confusing and I want to make sure Illustrator does not distort the resolution somehow for future reference.


Hope someone can help!


enter image description here


enter image description here


enter image description here




No comments:

Post a Comment

technique - How credible is wikipedia?

I understand that this question relates more to wikipedia than it does writing but... If I was going to use wikipedia for a source for a res...