XnView Software

Yes, I can confirm it

There is a bug in the octree method. The problem appears with less than 8 colors, with or without error diffusion and with or without 2-pass.

Thanks for the feedback, I'll work on this bug asap.

When creating 45º halftones from the built-in list, what mesh motive is used? I mean is the halftone made up of round dots, elliptical, square, or what?
Photoshop CS3's built-in halftone mode allow you to choose forms from Round, Elliptical, Square, Cross, Lines...

The halftones in the built in ...

2. lloyd algorithms is defined for greay-scale images? What algorithm did you implemented in your package for color images?

The K-means algorithm (or Lloyd's)
http://en.wikipedia.org/wiki/K-means_clustering
can be used in any n-dimensional space, you just needs a function which give you the ...

Can Hilbert-Peano curves (i.e. Riemersma) be considered some form of FM-Screening (stochastic) or are they a different thing?
I suppose your question is about hilbert-peano used in error diffusion dithering.

When the halftoning algorithms are classified into FM, AM and hybrid FM-AM, the error ...

Hello

Then, there appears heavy pink artifacts at the bar code. Is this normal?

More o less, it is something that happen in older versions, but I think I solved it.

This image shows I didn't and I must work on it again. :(

The issue only happen using the enhanced version.

Also, If you ...

Starting with version 2.9.0 the installer is no longer needed for the MP version.

I suppose you mean the .msi of the MP version of the Denoiser, it take more time because it install the multiprocessor libraries.

Good day, Blas. Merry Christmas to you.
Merry Christmas to you also. :)

I have another question regarding grayscales: Do you know how many levels (shades) of gray do produce error-diffusion methods (floyd-steinberg for instance)?
When using grids, you already pointed the right formulas to me ...

Doing a grayscale + error diffussion filter before, if the bitmap is a photographic image. The previous image was 16 colours already.

If you apply several grayscale transformations, the results are very difficult to analyze. Resolution and gray levels of the resulting image can't be calculated ...

Hello.

I test the image you post, comparing Ulichney 45 8x8 and Halftone 45 8x8. I get very similar results on screen, but I can't test it on a B/W printer.

The only way to mitigate them is to reduce the number of final grays before.
E.g. if you a are using a 45º 8x8 cell, reduce grays to 32 ...

eL_PuSHeR wrote:By the way. What does have to do error-diffusion (Ulichney) with the 45º cell halftones?

Both, the Ulichney error diffusion dither and the Ulichney clustered-dot threshold matrices comes from a book authored by Robert Ulichney.

Ulichney, Robert; "Digital Halftoning"; The MIT Press; 1987.

I think we talk about that previously.

There are two variables which control the quality of the result, the lpi and the gray levels

For 90º patterns (one point in each cell)
lpi = dpi / cellsize
levels = cellsize^2

For 45º patterns (two points in each cell)
lpi = dpi / sqrt(2*((cellsize/2)^2 ...

The problem in this image is that it was printed with "artistic" patterns. For example see the torch.

There are 3 band patterns. Those patterns are preserved by the more advanced denoise methods because those methods try to preserve everything but noise.

To remove this patterns with denoise ...

Hello I didn't notice your posts until today.

I have created some pseudo-diagonal screen halftones. Check them out.
Skin tones appear weird but they can be cool for line-art.
I test it and looks well.
It seems you have discovered how to create screens. :D

Hi, could you check this dithered test ...

Updated 2: Injected four filters again and deleted them in a row. No hangs so far (this is my computer at work). Could it be related to old-custom-filters leftovers in some way?. I will try at my home computer later again.
Could be.

The user thresholds are stored as subkeys of
HKEY_CURRENT_USER ...