Digital BW, The Print

Tom Husband wrote:
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Bob Frost"
> <bob@f...> wrote:
> 
>>Tom,
>>
>>Doesn't Qimage have to know what printer you are going to print to
> 
> in order 
> 
>>to do its interpolation and smart sharpening properly?
>>
>>Bob Frost.
> 
> 
> Bob,
> 
> That's a good question.  Possibly but it certainly doesn't ask for the
> printer when you print to file.  I'm not certain it needs to know the
> printer when you print through QTR because you specify a printer
> there.  That's not a good answer I know.  Maybe I'll ask over in the
> Qimage group.
> 
> Tom 

Before QTR was ported to Windows I suggested that the two, Qimage 
+ QTR could form a nice team.  Both in the Digital B&W list and 
the Qimage list.  How to connect them has been discussed in the 
Qimage list mainly. It's a pity that Qimage still delivers 
greyscale in RGB file format only and the "print to file" menu 
could use some extra features too. This isn't high on the list of 
"to do" according to Mike Chaney. But on the QTR side a lot has 
been done by Stephen and Roy.

In "print to file" of Qimage you can set the resolution. That 
resolution should be the native resolution that QTR uses for the 
printer you have. When asked Roy gave more or the less the answer 
that 720 PPI is the best input you can give the QTR but whether 
it will show more quality than 360 PPI has to be seen. Anything 
below 360 PPI should be upsampled to 360 PPI at least, preferably 
with better algorithms like Qimage has.

The other thing is whether the print sharpening of Qimage is 
suitable for B&W prints. Mike Chaney answered this:

 >Remains that question whether the interpolation and sharpening
 >> qualities of Qimage are as effective in B&W (quad) printing as
 >> they are in color. Or are there better algorithms for B&W only ?


The techniques should be identical.  I don't know of any reason 
to treat
B/W sharpening and interpolation any differently than color.

Mike

 >With a B&W image, you are altering only luminance values, so 
you should
 >> be able to use higher levels of sharpening..  That leads to a 
question
 >> of whether QImage currently defaults to higher sharpening 
values when
 >> sharpening B&W images?


Shouldn't matter.  Qimage sharpens based on the luminance channel to
begin with, even in color images.

Mike