[R] Artifacts in pdf() of image() (w/o comments)

[Michael Kubovy]

Hi Duncan,

I was trying to learn to remove the artifacts by setting the  
parameters of the image so that anti-aliasing wouldn't produce them  
(analogous to making sure that the screens of two halftone screen  
process images are in register before combining them so as to avoid  
Moiré patterns). So, I wasn't complaining; I was looking for  
instruction. Since the image was computed with R, it's reasonable for  
me to ask R experts to help me out of what I thought was caused by my  
ineptitude. (Regarding your question, "If it wasn't a bug, why did it  
bother you so much?"---there are many things that bother me that are  
not bugs.)

Moreover, I'm not opposed to complaining to Apple, once I have been  
assured that I'm not reporting a bug where there's none.

On Aug 13, 2007, at 9:56 AM, Duncan Murdoch wrote:

> On 8/13/2007 11:43 AM, Michael Kubovy wrote:
>> But is it a bug? Can a program anti-alias text and line drawings  
>> and  not bitmaps?
>
> Anti-aliasing is the removal of artifacts caused by displaying an  
> image on a low-resolution bitmapped display.  Introducing artifacts  
> is a bug.
>
> If it wasn't a bug, why did it bother you so much?  And why do you  
> think it's reasonable to complain about it on R-help, but not to  
> complain about it to Apple, who are clearly responsible for it?
>
> Duncan Murdoch
>
>> On Aug 13, 2007, at 9:30 AM, Duncan Murdoch wrote:
>>> On 8/13/2007 11:07 AM, Michael Kubovy wrote:
>>>> Dear Friends,
>>>> Thanks for your input.
>>>> FYI: Preview doesn't show PDF aliasing in the image I produced  
>>>> if  I  uncheck the "Anti-alias text and line art" box under the  
>>>> PDF  tab in  Preferences. So I'm not yet ready to drop Preview  
>>>> from my  toolbox.
>>>
>>> An alternative to dropping Preview is to report the bug in it to   
>>> Apple.  Apple has an online bug reporting web page somewhere; I   
>>> haven't found them as helpful as R-help, but your mileage may vary.
>>>
>>> Duncan Murdoch
>> _____________________________
>> Professor Michael Kubovy
>> University of Virginia
>> Department of Psychology
>> USPS:     P.O.Box 400400    Charlottesville, VA 22904-4400
>> Parcels:    Room 102        Gilmer Hall
>>          McCormick Road    Charlottesville, VA 22903
>> Office:    B011    +1-434-982-4729
>> Lab:        B019    +1-434-982-4751
>> Fax:        +1-434-982-4766
>> WWW:    http://www.people.virginia.edu/~mk9y/

_____________________________
Professor Michael Kubovy
University of Virginia
Department of Psychology
USPS:     P.O.Box 400400    Charlottesville, VA 22904-4400
Parcels:    Room 102        Gilmer Hall
         McCormick Road    Charlottesville, VA 22903
Office:    B011    +1-434-982-4729
Lab:        B019    +1-434-982-4751
Fax:        +1-434-982-4766
WWW:    http://www.people.virginia.edu/~mk9y/