Image Writer Plugin Sample Code - unexpected color results

[Ian Grant]

Hi,

I was just playing with the Image Writer Plug-in sample code - and  
seem to be getting unexpected color results:

Sample Code:
/* Figure out pixel format and colorspace to use */
        colorSpace = [qcImage imageColorSpace];
        if(CGColorSpaceGetModel(colorSpace) == kCGColorSpaceModelMonochrome)
        pixelFormat = QCPlugInPixelFormatI8;
        else if(CGColorSpaceGetModel(colorSpace) == kCGColorSpaceModelRGB)
        pixelFormat = QCPlugInPixelFormatARGB8;
        else
        return NO;

...

cgImage = CGImageCreate([qcImage bufferPixelsWide], [qcImage  
bufferPixelsHigh], 8, (pixelFormat == QCPlugInPixelFormatI8 ? 8 : 32),  
[qcImage bufferBytesPerRow], colorSpace, (pixelFormat ==  
QCPlugInPixelFormatI8 ? 0 : kCGImageAlphaPremultipliedFirst |  
kCGBitmapByteOrder32Host), dataProvider, NULL, false,  
kCGRenderingIntentDefault);
        
<<inline: PreviewScreenSnapz001.png>>


I've experimented changing the parameters of CGImageCreate().

Is the CGImage (with the default example code) supposed to always be  
greyscale? [ apologies if I simply have misunderstood the code]
What CGImageCreate() parameters would I need to match the colorspace  
of the default QC context?
and
When would the [qcImage imageColorSpace] return anything other than  
default [linear?] RGB?
In my composition QC generates the source image with a 'Render in  
Image' patch. What colorspace would images created internal to QC be -  
with color correction and without color correction?
If I imported an image with a color profile, do color spaces get  
respected [I assume 'yes' with color correction selected]?

In what context with images created in QC would the colorSpace return  
as Monochrome?

I read the threads from Jonas S 'QCRenderer colorspace problems [was  
QCRenderer work area size]' and Raphael Sebbe 'QCRenderer and  
colorspace parameterizing'.

Thanks, any insights would be welcome.

Regards, Ian


*******************************
Ian Grant
Senior Lecturer in Digital Art
Faculty of the Arts
Thames Valley University
Ealing, UK
W5 5DX
<[EMAIL PROTECTED]>
*******************************



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