Re: Color space for cmyk eps images converting to rgb
Re: Color space for cmyk eps images converting to rgb
- Subject: Re: Color space for cmyk eps images converting to rgb
- From: "Ken Ferry" <email@hidden>
- Date: Mon, 22 Dec 2008 11:21:36 -0800
Hi Ken,
The -colorSpaceName method on NSImageRep returns only a best-effort
approximation. This method, like many of the methods of NSImageRep,
is used by NSImage to decide which NSImageRep is the best choice for
drawing to a given destination. The design is easiest to comprehend
from that point of view. If an image rep doesn't have a 'home'
colorspace, calibrated RGB is the default.
EPS on Mac OS X is handled by converting the data to PDF. The
interface NSEPSImageRep uses is documented here:
<http://developer.apple.com/documentation/GraphicsImaging/Reference/CGPSConverter/Reference/reference.html>.
I'm not familiar with the EPS format (since we just convert it to
PDF), but a PDF doesn't have any one colorspace. Different embedded
bitmaps may have different colorspaces. We do not look through the
included bitmaps for a most popular colorspace or anything like that.
This is more of an explanation than a workaround. You can and should
file a bug, but even if you can define exactly what you want to have
happen, you'll have to go it alone for now.
-Ken
Cocoa Frameworks
On Sun, Dec 21, 2008 at 10:04 PM, Ken Tozier <email@hidden> wrote:
> Hi
>
> If you open an eps image in a text editor like BBEdit, you can see clearly
> what color space it was saved as but when you create an NSImage from the
> file and call [image representations] or [image bestRepresentationForDevice:
> <printer device dict here>] all you get are images with
> "NSCalibratedRGBColorSpace." Most of our images are saved as cmyk so why is
> NSImage ignoring that info and replacing it with rgb? Is there any way to
> load eps's differently so that their saved color spaces are preserved? I
> could write a little hack to read the eps header directly and extract the
> info, but I'd like to avoid that if there is a way to do it with NSImage.
>
> Reason I ask is that I wrote a file cataloging application and one critical
> piece of info is the color space, so users will know, at a glance, whether
> an image they are about to import into a print document needs to be
> converted to cmyk.
>
> Thanks for any help
>
> _______________________________________________
>
> Cocoa-dev mailing list (email@hidden)
>
> Please do not post admin requests or moderator comments to the list.
> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
>
> Help/Unsubscribe/Update your Subscription:
>
> This email sent to email@hidden
>
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden