Digital BW, The Print

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.

----- Original Message ----- 
From: "Tom Husband" <thusband@...>

Yes, I use Qimage and the Print to File feature to print to the
monitored folder in QTRgui or just to the desktop and then drag the
image to QTRgui.  It works well for single images but I haven't tried
it with with multiple pages.

Qimage's interpolation and Smart Sharpening is second to none.

--- 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

Tom,

I asked because AFAIK when you print with Qimage, it interpolates the image 
up to the ppi used internally by the printer driver. For epson desktops that 
is 720ppi, for epson wideformats 360ppi, and other printers such as HP and 
Canon use different values, eg. 600ppi. All that info is I believe, stored 
in QImage (or it gets it from the printer driver each time), which is where 
the 'intelligent interpolation' and 'smart sharpening' come in.

If you use another driver such as QTR to print with, you presumably have to 
know what ppi it prefers internally, in order to be able to use Qimages 
interpolation and smartsharpening to its best advantage.

I'm not saying you can't use Qimage and QTR, just suggesting it might not be 
any different to using PS and QTR; you have to choose the interpolation and 
sharpening instead of QI doing it for you when it prints throught the normal 
printer drivers.

You need Mike Chaney or Roy Harrington to clear it up.

Bob Frost.

----- Original Message ----- 
From: "Tom Husband" <thusband@...>


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 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

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

Would this mena that sharpening in ones workflow should be abandoned 
if using Qimage?

Thanks,

Don Bryant

donbga wrote:
> 
> Ernst,
> 
>>Shouldn't matter.  Qimage sharpens based on the luminance channel to
>>begin with, even in color images.
> 
> 
> Would this mena that sharpening in ones workflow should be abandoned 
> if using Qimage?
> 
> Thanks,
> 
> Don Bryant

Sharpening to get an image you like on the monitor is alright. 
The sharpening for the print doesn't look nice on the monitor but 
is good for the print.  That print sharpening is something you do 
not want to keep archived in the image file as it relates to the 
size and the type of print. Qimage does that sharpening at the 
right moment and in a controllable way.

Bruce Fraser has some pages on the subject of sharpening stages 
in image processing,
a google:
http://www.google.com/search?q=%22Bruce+fraser%22+sharpening+stages&sourceid=mozilla-search&start=0&start=0&ie=utf-8&oe=utf-8

Ernst