Comments for KrazyDad

Comment on Systematic Sudoku by John Welch

John Welch — Thu, 21 Mar 2013 15:55:06 +0000

Thanks for your endorsement, Jim. It means a lot to me. I’ll do my homework and get back to you on the notation questions very soon.

Comment on Systematic Sudoku by Rubens Mariuzzo

Rubens Mariuzzo — Wed, 20 Mar 2013 14:03:39 +0000

Thanks! I’m really into solving tricky puzzles.

Comment on The mark of the unicorn by Eduard Schwan

Eduard Schwan — Sun, 09 Dec 2012 04:47:33 +0000

What a delight to bump via a random walk into another unicorn… I too loved the elegant simplicity of bresenham line interference patterns, fractals, and simple programs that did complex things… Looks like I have quite a bit more perusing to do on your site and blog… Some great software here… And yes, dewdney and Gardner were much discussed in my house growing up (I just rediscovered hexaflexagons and made a bunch as gifts this year). Consider yourself bookmarked! :)
Ttfn,
Eduard

Comment on The mark of the unicorn by Damon

Damon — Sat, 08 Dec 2012 19:19:57 +0000

I think we used to call you Unicorns “Pirates”.
Personally, I still do.
I’m doing WordPress production at a Medical Marketing Agency over by LAX..
Boob Bob before-and-after images et al & PHP.
Low stress so I can focus on other intellectual pursuits for a change.
And yeah..I’m enamored with you crazy auto-didact types that sat up till all hours in your childhood manipulating pixels and found an entire universe in it.
And you, Sir, are a river to your people.
Like Clint says in “Outlaw Josie Wells”
“I rode with ya..I got no complaints.”

Comment on Get started with Jigsaw Sudoku by jbum

jbum — Wed, 19 Sep 2012 19:15:34 +0000

Thanks for catching that Susan, I’m fixing it now.

Comment on Get started with Jigsaw Sudoku by Susan

Susan — Wed, 19 Sep 2012 13:59:43 +0000

Hi, Thank you so much for your careful, patient explanation of innies and outies as used in Jigsaw Sudoku – most of the other explanations I have found relate to killer Sudoku, which is not my thing!
Just one point – I think (unless I’m being dumb) you have made a teensy error in your last example: surely the options for the two boxes are only 7 & 9 – you already have a ’4′ in the fourth row? …. even so, thanks so much for the explanation. Happy puzzling!

Comment on Graffiti Shroud by jbum

jbum — Wed, 22 Aug 2012 18:52:58 +0000

Yes, I wrote a Processing program to do it. The algorithm is essentially:

1. Start with a random assortment of 300 photos from the larger the list (of 20,000 photos).

2. For each unselected photo, A from the set of 20000

3. For each B of the 200 selected photos

4. Swap A and B.
If the swap produces a better match to the target image, keep it.

I repeat from step 2 until no progress can be made.

The “better match” is the same type of matching used for photo mosaics. I compute the sum of the RGB differences for each pixel. Lower sums are closer matches.

Comment on Graffiti Shroud by Lars

Lars — Wed, 22 Aug 2012 18:42:25 +0000

This is an interesting effect.

I assume you “carefully choose” the 300 photos using a program, correct (not manually)? What’s the algorithm like?

Comment on Graffiti Shroud by jbum

jbum — Sun, 19 Aug 2012 04:37:44 +0000

What I’m doing uses integers, but it shouldn’t accumulate errors in the way you describe.

I have an array of integers which represent the sums of the R,G,B components of each pixel. For each image, I add it’s value to the array. So, for the pixel at 0,0, given 3 images, I might add the following values:

Image 1: rgb(0,0) = 50, 60, 50
Image 2: rgb(0,0) = 62, 72, 100
Image 3: rgb(0,0) = 200, 198, 170
————
This produces: 312, 338, 320

After I’ve added all the images. I then scale the numbers (“normalize” them) so that the lowest value maps to 0, and the highest value maps to 255.

Comment on Graffiti Shroud by Nick Porcino

Nick Porcino — Sun, 19 Aug 2012 03:21:07 +0000

Are you doing the blending in floating point, or integer? If integer, cumulative error gradually push pixel values to the corners of the color cube and muddy colors result. If you’ve already done the blending in float I have no explanation :)