[scribus] Open Source PDF pre-flight tool? -> contrast curves

[a.l.e]

hi
>> Hi John,
>>
>> Ah, "massaging the contrast curves" sounds like just the kind of hint
>> I was fishing for. I'll go read up on that in the Beginner's Guide :-)
>>
>> Many thanks for the tip!
>>
> This is best done in Gimp or Krita. I don't think Scribus has
> this facility internally.
>
>

scribus has the facility and it can be interesting for some use cases 
(as an example, when the image is interacting with text placed around or 
below it)

item > image effects

but generally speaking, yes you should prepare your image before 
importing it into scribus.

ciao
a.l.e