Mike Chaney's Tech Corner

I am testing out Q-Image and have found that the Lanczos setting works best for what I am doing (I use lanczos in another program currently) but It looks as though the Lanczos setting is applying both a blur and a sharpen to an Image.

I am mainly looking at q-image for the template features but there seems to be a couple of extra things going on in the print process.  I don't necessarily object but I would like to know what effects are being applied to my image.   

I am judging only from the prints and would like to know the following if possible:

What Lanczos are you using ?   3, 5, 8 ?

Are you applying a Gaussian blur and unsharp mask automatically ?

In the print quality challenge on your website you state that 720 is the native resolution for Epson Drivers but in Q-Image ultimate the max setting is 360 PPI.   Is 360 enough since it is easily divided in to 720 (thus no rounding errors)

Thanks,   I appreciate your time and also very much appreciate that you have a fully functional demo.  I like what I am seeing so far.

Bob,
This I have no idea, will have to wait for Mike, the author to fill you in.


You didn't mention what model Epson you have, but all the ones I have ever tried do have 720 ppi input, albeit some models require a road map to find the switch.
What model Epson??

As for introducing any blur, not so unless you turned on a filter for softening. There is no Unsharp Mask turned on either except if you are using Raw image mode and have the Raw Option set too high.
There is one other item and that would be Smart Sharpen which should be at default (5). If you ran that option up to a 15 or a 20 in JOB PROPERTIES, you might see far too much sharpening in your prints.

Fred

Hi Bob,

If you go into the epson driver - print 'quality' settings, or similar, and set to highest quality, and highest dpi, then you will probably find that miraculously qimage print resolution will give a 720dpi choice. However, for larger prints, 360 is more than adequate.

Best wishes,

Ray

Actually, the newer more pro printers from Epson  require that you look for the setting called Finest Detail. See screen snap attached.
It isn't an obvious option, but it is there.

Fred

btw, the quality options will also depend on the media type, and afaik, unless both dpi's are greater than or equal to 720 then the 'finest detail box' can not be selected. You have to select 'quality options' to get to the screen that Fred has shown. The preset quality settings do not appear to include the finest detail option, at least for the media I normally use, but that may vary between drivers, however I do not use the presets when printing my images.

Best wishes,

Ray.

Ray,
I have checked three drivers, and most all the paper choices, and I find only PLAIN paper grays out finest detail which is the 720 ppi setting.
I even tried all the artsy papers and the proof papers. I can get 720 ppi.

Even Plain Paper can be set to 720 DPI, but you cannot get 720 ppi (FINEST DETAIL) selected with plain paper even though you can get 720 DPI.

The point is, to me, that if a user wishes to wait the extra printing time to get the maximum quality from his printer, he needs only to tick a box.
That's what this thread was about.
Fred

Not all media has all 5 settings available, and for different media the values (1 to 5) do not relate to the same dpi. The actual value (1 to 5) is specific to the media, and relates to dpi and the amount of microweaving applied (and possibly other stuff too). If you do not use the 'quality options', but use the print quality presets, then afaik, the dpi in qimage does not give a 720dpi option.

I expect, initially, many folk would probably, in the driver main window, select 'Max Quality' in the 'Print Quality' drop down menu for their particular media, and then be puzzled by the fact that qimage sat at 360dpi. The 'quality options' selections in the printer driver do not apply to the other quality presets, which could be considered a bit odd. I think the expectation could be that provided the epson driver has been set to a dpi greater than 720, then qimage would allow the option of printing at 720dpi.

In effect, the 720 dpi printing from qimage is selected by the 'finest detail' checkbox in the epson driver if you happen to stumble across that, and then can get it to be checkable. (This is not difficult to do, once you know how, but from a users viewpoint it is tending towards obfuscation).

Best wishes,

Ray

PS my comments relate to what appears to be so in qis, may not be same for qiu

Ray,
Just to set the record straight. Qimage, regardless of version, reports what the driver is doing. Qimage does not interpret things differently from any other program.
Nothing more than that!!
Talk about obfuscate!

: :D :D :D
Fred

It's a radius 3 Lanczos.  Years ago when Lanczos was still popular, I did extensive testing and found that running Lanczos at more than a 3 radius gave near zero benefit but had a big impact on speed.

There is no softening/blurring unless you are DOWNsampling at which point, antialiasing is needed.

Curious what you are doing that would choose you to pick Lanczos.  Those "old" algorithms like Lanczos and bicubic have a lot of ringing that equates to increased noise.  Even the simple/fast vector is better for photos.

Mike

Thanks For the answer,

In my testing I was upsizing a Zone Plate File (256 px by 256 px) to 7 inches by 7 inches in q-image.   I tested the Vector and Hybrid SE also with this file but found that for this type of file,   The Lanczos performed much better.   

I compared the results from Q image to a print made by manually upsizing in Graphic converter to 360pp and 720ppi using Lanczos 3 and Lanczos 5.    Out of all the prints the one from Q Image was quite a bit better.   (all of the prints where much better that upsizing in photoshop with Bi-Cubic)

Since I had no sharpening applied they should have been the same. 

I am glad that the Q-Image print was better but it should not have been.  The edges of the concentric circles in the zone plate looked very much as if they had been slightly blurred and then sharpened.   Don't get me wrong,  It looks produced the best print and I am glad but visually it was obvious that there was some improvement made that was beyond simply using lanczos to interpolate.

I am using an Epson 3880 in this test but also have an Epson 7880.   I am doing printing for an engineering company that needs several drawings of mechanical parts printed.  The drawings are old and low resolution. 

Hi Fred,

What I am saying that there is little natural relationship between 'finest detail' and qi dpi choices, other than checking that box will allow 720 dpi in qi. Even if folk were to rtfm the driver help says - and that seems to imply that is not the ideal selection for printing large photos. Now, to you, that may well read that it is the ideal setting for printing large photo images, but that conclusion is possibly based on other information, not what epson states i.e.  because you know that is the setting you need for qi 720dpi.

Anyway, never mind what Epson implies, or whatever, check the box and you can print at 720dpi from qi. :)

Best wishes,

Ray