Re: Help with pixellated NSTIFFRepresentation issues much appreciated

FROM : Aaron Fothergill
DATE : Tue Oct 12 21:46:28 2004

Are you using NSImage setScalesWhenResized by any chance ? If so, you
probably don't need to (drawInRect: fromRect: etc. does a non permanent
resize of the graphic when it's used without scalesWhenResized). If
setScalesWhenResized is on, whenever your graphic is redrawn at any
size, the graphical data for it is resampled at that size. So if you
draw it small at any point, you end up with a lower resolution image as
your source.

Aaron
_____________________________
Aaron Fothergill  :  MD / Lead Coder
Strange Flavour Ltd
<email_removed>
http://www.strangeflavour.com
On 12 Oct 2004, at 20:39, Keith Blount wrote:

> Many thanks again for the reply and help.
> Unfortunately, I tried this and it didn't work either
> - there was no change.
>
> I tried a different tack which had some minor success.
> Everytime I zoomed the image, I created an
> NSBitmapImageRep of the correct proportions (using
> setPixelsWide and setPixelsHigh), and then created an
> NSImage containing only this image rep (using
> addRepresentation:). This was then the image that I
> added to the pasteboard using TIFFRepresentation. This
> method worked, but only properly with the original
> image. That is to say, after starting the program with
> an image in the image view, I could zoom the image to
> the largest possible, then drag and drop it into the
> text view correctly. I could then drag the image back
> from the text view into the image view and zoom it
> with no loss of quality. However, it would then only
> zoom up so far before the image snapped back to the
> size it was when originally dropped. So ultimately,
> this method doesn't help much either...
>
> I have thus decided to give up on this for now, as
> this was only supposed to be a minor part of my
> program (which is mainly a writing and outlining
> program) and I have been bogged down with this problem
> for nearly two weeks, and this idea was in itself a
> compromise anyway. What I initially wanted was for the
> user to be able to resize a picture within a textview
> itself just as you can in Word or Nisus Writer Express
> (click and drag on the image to resize), but had no
> idea of how to go about this. So as I already had a
> zooming image view, I thought I would be able to drag
> and drop zoomed images between this and the text view
> as an easier alternative. As it turns out that this is
> actually no easier at all, I think I will just have to
> put the whole resizing-of-images-for-text-views thing
> on hold and come back to it later (though of course,
> if anybody knows where I can find any examples/clues
> on how to do this, it would be *hugely* appreciated).
>
> Many thanks for all the help trying to get this idea
> to work, though, I really do appreciate it. If I ever
> figure it out, I will be sure to post the solution.
> Keith
>
> --- Robert Clair <<email_removed>> wrote:
>

>>> Sorry for my lack of clarity. Basically, if I just

>> use

>>> [self image] to create the TIFFRepresentation, the
>>> results seem random in that - for any image I

>> place

>>> into the image view - when dragged to the text

>> view

>>> the image may be completely unscaled, or it may be
>>> scaled correctly, or it may be scaled but at a
>>> previous scale (eg. not at the original size but

>> not

>>> at the size the image is in the view, either).

>> Very

>>> strange.

>>
>>
>> Let's try this from the top. I don't know what
>> NSImageView is doing,
>> I don't use them. But try this first  - whenever you
>> create an image -
>> loading it from the file or from a pasteboard,
>> immediately do:
>>
>> [whateverImage setScalesWhenResizes: YES];
>> [whateverImage setDataRetained: YES];
>>
>> the setDataRetained: YES will keep NSImage from
>> replacing your
>> NSBitmapImageRep with a lower res NSCachedImageRep
>>
>> then your original easy
>>
>> [[self image] TIFFRepresentation];
>>
>> should work.
>>
>> ......Bob Clair
>>
>>

>
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