While driving home to LA from a New Year's in San Francisco, we passed through the tiny town of Harmony, CA (pop 18) where I happened to photograph master glass artist Eric Dandurand. That photo was recently published in Journal Plus, Magazine of the Central Coast, May 2009, p 12
You can make fairly complex patterns in Photoshop by randomly shuffling simpler patterns. This is a Photoshop reprise of material covered for Maya here.
This 'maze' is composed of 4 randomly shuffled tiles.
The tiles are interchangeable. They all connect in the middle of each edge.
Each tile was defined as a pattern and filled as a repeating sheet.
I also made a 16 x 16 image of noise, blew it up 'nearest neighbor - no interpolation' to match the sheet sizes, tone-leveled it and posterized it to 4 values: black, dark gray, light gray, and white.
(click image for a much closer look)
I magic-wanded (non contiguous, with 0 tolerance) each of the 4 gray levels and turned them into layer masks. This caused the tiles to randomly 'shuffle.'
The maze tiles with itself, even if rotated in increments of 90 degrees.
In computer graphics this technique is called texture bombing.
Instead of matching grays to random tiles, I matched them to hand drawn patterns of appropriate values, and create an artistic dither or simple photo mosaic.'
I hand drew symbols of appropriate brightness (using Filters > Blur > Average to gauge the average intensity of the image) My hope was to create a portrait of the model Scar 13 in Hawaiian wardrobe that looked as if it were made from Tapa Cloth.
(click image to see full size)
I used the Threshold tool and a set of known values (in this case of 16 zones I went from from 0/15*255 to 15/15*255 -- see 1:43 video for a rapid spreadsheet solution). I selected, magic wanded, and layer masked ever smaller, brighter areas as I rose level by level through the Photoshop layer stack.
What I ended up with is a bit like overstrike ascii art from the 1970's, which is what this process produces when tile values correspond to mosaic tile values. So if that's something you want, here is a method for 'eyeballing' a custom one just for yourself. (The work is mainly in creating a set of correctly weighted tiles) When I first started playing around with photo mosaics in the early 90's I originally experimented with Chuck Close-style abstract painted targets and swirls. I was reminded a lot of those days while I painted these Tapa cloth tiles. : )
So I was visiting Filter Forge to see if I could implement this 'maze' pattern and maybe earn myself a free copy of the $300 plugin, when I noticed there was a similar (but simpler) pattern already there called Truchet tiling, which uses only a pair of triangles, or the arc pair tile above. I think I like mine better. :)
It occurs to me you can use the Photoshop dissolve blend mode to create the random noise patterns.
I had imagined generalizing this into interlocking tile illustrations for a game or children's mural. I noticed on boingboing tonight that someone was also thinging along those lines.
I'm going to start keeping track of online sources of fonts that look interesting. Some free. Some not free. The main criteria will be, do I want to 'bookmark' this link? They are in no particular order.
The Black and White Adjustment Layer has a nice ability to target and boost or suppress narrowly defined hues. For example, it can affect red without affecting yellow. That's something you can't do with curves.
In this video I'm experimenting not with what kinds of black and white images can be made from the Black and White Adjustment Layer, but what kinds of color images can be made using it.
Is still a bit of a mystery to me. I had created a screencast in pieces using a cheap microphone that creates a baseline silence that is anything but. My first thought was to cross-fade the 'silences' to smooth the transition from one cut to the next, but I was getting volume dips in the middle of the audio dissolves.
Maya models 'incandescence' by pumping flat cartoon color into an object to mimic light radiating equally in all directions, but it looks like from this photo that even a radiant ball like the sun actually has falloff at the edges.
Maybe Maya should build in a 'facing ratio' light contribution option.
...although when I 32-bit HDR-dim-down a finely-smoothed Platonic solid emitter in Maxwell, I see no signs of falloff. So maybe what I see in the sun photo is due to something other than how many rays from a given area get sent toward the camera.
The Inverse Square Law is not an innate property of light. The ISL is a property of expanding spheres. When light does not expand spherically (as in a collimated beam) or when the source cannot be approximated by a point, then light seems to 'violate' the Inverse Square Law.
If you have a distortion filter that is reversible you can pre-distort an image, apply an 'art filter' to the distorted image, then un-distort the image. The result? The 'art filter' is distorted, while the image itself seems undistorted.
Unfortunately not enough Photoshop distortion filters are reversible, but I could probably back calculate an inverse displacement to a distortion by applying it to an image of absolute pixel addresses - an idea I partially present here:
I was reasonably successful in using channel calculations to compute displacement maps that undo other displacement maps. The quality is somewhat limited by things like Photoshop's refusal to displace in higher than 8-bits, but below is a test.
I used Perlin noise Photoshop 'clouds' to displace a photo, then I applied the mosaic filter. Finally I reversed the displacement so that the photo was normal, but made of rippled 'mosaic' tiles.
I reversed the displacement by applying the same displacement to an image of absolute pixel address (the yellow, red and green 'UV' image) and subtracting the undistorted version from the distorted version to get an image of relative displacements.
I noticed that every time you apply certain filters to an image they run differently each time. I thought it might be fun to check out the image stacking in Photoshop's new 'extended' versions.
I chose coarse settings for the pixelate > crystallize filter - course enough to disguise the photo. Below is a stack of 8 such images averaged together. The more you use, the less the filter disguises the original.
Here is a (tedious) method for stacking images without the extended version of Photoshop
I was playing around with this. For image averaging you don't actually need Photoshop Extended. You can do it in any version of Photoshop that supports 32-bits:
Stack the images in layers. Use the LINEAR DODGE (ADD) blend mode to sum all the layers. You will blow out the image way past white. No worries. Kick into 32-bit mode and dim the sum (no pun intended :D ) back into a usable range. For a true average, dim it by a factor of (1 / N layers)
Use the Black and White adjustment layer to eliminate col-erase non-photo blue pencil sketch lines from a scan of inked artwork. (or many other pencil colors - experiment with hues other than blue - this approach is more versatile than those methods involving eliminating or copying a single color channel)
(click image to see larger)
Adjust one or more sliders, use mainly the cyan slider in the case of Col-Erase non-photo blue, until you target the precise hue of pencil you need to eliminate. The process occurs interactively as you adjust the slider.
In Photoshop, a MULTIPLY blend mode is equivalent to an AND logic gate. When two images are multiplied, both have to be bright to produce a bright result. If either one is dark, the result will be dark.
A SCREEN blend mode can be replicated exactly by inverting two layers, multiplying them, and inverting the result. De Morgan's rules. This means that if a MULTIPLY blend mode is analogous to an AND Boolean logic gate then a SCREEN blend mode must be an OR gate. And sure enough, it is analagous to one. In a SCREEN blend, if either layer is bright (or if both are bright) then the result will be bright. Since SCREEN mode is derived from MULTIPLY mode using essentially De Morgan's rule, it would seem that SCREEN is a 'better' description of an OR gate than Linear Dodge (Add) is.
It also turns out that the transformation between MULTIPLY and SCREEN works the other way, as well. A MULTIPLY blend mode can be created by SCREENING two negatives and inverting the reult, also as predicted by De Morgan.
DIFFERENCE blend mode acts like an EXCLUSIVE OR (XOR) gate. If either layer is bright the results will be bright. If both layers are bright the results will be dark.