Stereograms by Scott Pakin

I like trying to develop innovative new techniques for constructing autostereograms. Here, in chronological order, are a number of wall-eyed autostereograms I drew and a description of what I was trying to achieve with each. Enjoy!

Apple and Orange Apple and Orange I was curious if I could produce an autostereogram containing colored objects—something as close as possible to a true-color autostereogram. In Apple and Orange I tried to color the apple red, the orange orange, and the shelf they’re sitting on brown.
Wooden Chair Wooden Chair I was wondering if it’s possible to produce an image that’s simultaneously an autostereogram and an anaglyphic stereogram (to view through red-cyan glasses). Wooden Chair is my first attempt to produce such a unified stereogram. The anaglyph image looks good, but I wish that the autostereogram were crisper.
Beach Ball Beach Ball This is an experiment in including (faux) transparency in stereographic images. In Beach Ball, note how the ball has red spots in front and purple spots in back, and you can see the purple spots through the transparent red spots. I like how this image turned out.
Pottery Sale Pottery Sale This image represents an attempt to combine a wallpaper stereogram and a single-image stereogram. In Pottery Sale, the pottery is a wallpaper stereogram while the back wall and the front of the table are both single-image stereograms.
Memories Memories I wanted to see if it’s possible to use more than one tiled pattern in a single image. (Answer: yes. 😀) Notice how in Memories, the pattern fades from an alphabet in the upper-left corner to raspberries in the upper-right corner to dice in the lower-right corner to roses in the lower-left corner.
Who’s on Top? Who’s on Top? Let your eyes diverge when looking at this wallpaper stereogram. You should see the array of cubes floating above the array of spheres, which in turn are floating above the patterned background. Rotate the image (or your head) 90°. You should now see the array of spheres floating above the array of cubes, which in turn are floating above the patterned background. I’d love to perform a similar trick with a single-image stereogram but don’t know how.
Bowl of Gems Bowl of Gems Like Pottery Sale above, Bowl of Gems combines a wallpaper stereogram and a single-image stereogram. However, Bowl of Gems places the wallpapered objects (gems) on top of the object represented by the single-image stereogram (a bowl). Not only that, but different gems appear at different depths based on the depth of the underlying bowl. (That took a lot of trial and error, incidentally.)
Empty Table Empty Table In Empty Table I used a single tiling pattern throughout the stereogram but varied the brightness. The result is an image that includes both illuminated and shadowed regions.
Scattered Shards Scattered Shards I struggled for a long time to find a way to produce a stereogram that can be tiled both horizontally and vertically. All of my attempts ended up being flickery and hard to focus on. Eventually I gave up trying to tile arbitrary objects and limited myself to abstract shapes, which are a lot easier to deal with. You can see the result of my efforts in Scattered Shards. Maximize your browser window to get the full effect.
Lovesick Lovesick I was aiming for minimalism here—just a few dots on a solid background. Unfortunately, making the 3‑D image sufficiently clear required a lot more dots than I had intended. The good news is that I found that I could create a nice transparency effect à la Beach Ball (above) by superimposing two stereograms: one showing the top half of the object and one showing the bottom half of the object.
Winter Scenes Winter Scenes This may seem like an ordinary stereogram. However, it’s really a subtle experiment with color. Once you’ve viewed the stereogram, try converting the image to grayscale then normalizing the gray levels. The result probably isn’t what you’d have expected.
Exclamation Mark Exclamation Mark I’ve made some progress towards the goal mentioned in conjunction with Who’s on Top? (above): developing a single-image stereogram that contains a different image when rotated 90°. Exclamation Mark portrays a boxy exclamation mark lying within a crease. Rotate the image (or your head) 90°, and the exclamation mark vanishes while the crease remains. The rotated image isn’t super-crisp, but I’m pleased that the basic effect seems to work.
Stonehenge Stonehenge Like Bowl of Gems (above), this image superimposes a wallpaper stereogram over a single-image stereogram. The difference is that in Stonehenge the wallpapered image (a line of people—who were supposed to be druids, but that’s beyond my artistic ability) not only changes depth but also rotates as it repeats from left to right.
Every Which Way Every Which Way Aha! I finally figured out how to produce a stereogram that can be horizontally and vertically tiled yet can portray arbitrary shapes. While the approach used in Scattered Shards (above) handles only abstract patterns, my new approach is far more flexible. Every Which Way successfully represents a bunch of 3‑D arrows pointing in different directions. Maximize your browser window to get the full effect.
Put on a Happy Face Put on a Happy Face When not viewed wall-eyed, single-image stereograms normally appear as a tiled pattern with some distortion (or as random dots that obscure the tiling and distortion). I wanted to see if I could produce a single-image stereogram comprising exclusively undistorted shapes. Put on a Happy Face is the result. Note how it looks like an unassuming grid of emoticons, but diverge your eyes, et voilà!, a 3‑D image emerges. For contrast, an alternate version of Put on a Happy Face shows what the stereogram would look like with the usual distorted-tiling approach: uglier 2‑D but crisper 3‑D.
The Color of Music The Color of Music Observe how the colors in this image vanish when viewed as a stereogram. Pretty neat, huh? I aligned complementary colors in such a way that they cancel each other out when overlapped, and that seems to have worked exactly as intended.
String Theory String Theory Is it possible to draw a single-image stereogram without taking your pen off the paper? String Theory demonstrates that it is. An SVG version of String Theory is also available as further evidence that single-image stereograms do not necessarily have to be bitmaps; vector graphics can work as well.
Spider and Web Spider and Web New autostereogram artists quickly learn that thin lines are imperceptible when viewed in 3‑D. I wanted to see if I could include thin lines in an autostereogram and make them viewable by altering the 2‑D pattern to enhance their visibility. Spider and Web is my first attempt to do this. The thin lines that constitute the spider’s web aren’t perfect, but I believe they do demonstrate the feasibility of the technique.
Tintinnabulation Tintinnabulation Tintinnabulation takes the notion of an ASCII stereogram one step further. It demonstrates that an autostereogram can be constructed from undistorted, proportionally spaced text merely by adjusting inter-character spacing and dropping characters when necessary. (In case you don’t recognize the text, it’s the first 1½ stanzas of Edgar Allen Poe’s, The Bells.) Note that the PDF version of the Tintinnabulation stereogram is fully searchable.
Rotated Squares Rotated Squares This one was a surprise to me. I was experimenting with rotation to see how well the eye can tolerate changes in angle in an object-array stereogram. I didn’t expect to see the wavy pattern that emerges when Rotated Squares—comprised entirely of evenly spaced and equal-sized but differently rotated squares—is viewed in 3‑D. An SVG version of Rotated Squares is also available.
Row of Trees Row of Trees Row of Trees is what’s called an object-array stereogram, which means that there’s no hidden 3‑D image. Instead, when the picture is viewed wall-eyed, the (visible) objects in the image take on depth. What makes Row of Trees different from other object array stereograms is that it was created entirely from photographs taken at different angles, with no 3‑D computer modeling. The depth you perceive is therefore the natural depth of the scene.
Child’s Play Child’s Play This is an attempt to combine two types of stereograms: hidden-image stereograms and object-array stereograms. The small toys repeated throughout the picture have depth when viewed in 3‑D but are also positioned at precise heights so as to define a large 3‑D image. The small objects exhibit less depth than I would have liked, but I believe that overall this is a good proof of concept.
Caged Creature Caged Creature The idea here was to superimpose an object-array stereogram atop a conventional, hidden-image stereogram. What makes this interesting is that the object in the object-array stereogram is in fact a hole through which the conventional stereogram can be seen. The rest of the object-array stereogram is solid black.
Magic Hat Magic Hat The only interesting thing here is that the 2‑D pattern fades from showing a normal Abracadabra on the right side of the image to a reversed Abracadabra on the left side of the image.
One Cent One Cent This hidden-image stereogram is a photograph, only minimally retouched (straightened, cropped, resized, and white balanced). The things I learned from this exercise are that (1) it’s really tedious laying out dozens of pennies on a sheet of paper, and (2) with a 19mm diameter, pennies form rather large pixels. Consequently, I was able to make the underlying height map only 10×8 pixels—0.01% of the resolution of most of the other stereograms on this page. In case you can’t decipher the 3‑D image, it’s supposed to say on a sloped background.
Butterfly Butterfly This stereogram is both horizontally and vertically symmetric. Flip it across either Cartesian axis, and it will look the same.
Snowflakes Snowflakes When viewed in 3‑D, one snowflake appears higher than the other in this object-array stereogram that is also a valid QR code. The snowflakes are a little hard to focus on—perhaps try each in turn—but the stereogram does work well as a proof of concept. I used Russ Cox’s QArt Coder to produce the QR code.
King Me King Me Like Put on a Happy Face (above), King Me is an attempt to construct a stereogram entirely out of undistorted shapes. Unlike Put on a Happy Face, however, King Me allows the shapes to overlap, which produces a crisper image. The 3‑D image, which is supposed to be a crown, isn’t as detailed as I’d like, but that’s a subject for a future stereogram.
We All Scream We All Scream The idea here was to combine the coloring of Apple and Orange, the transparency of Lovesick, and the undistorted shapes of King Me. Unfortunately, the 3‑D image, which is supposed to be an ice-cream cone, is a bit abstract and, quite frankly, doesn’t look nearly as nice as I would have liked.
Goldfish Bowl Goldfish Bowl Here’s a fun stereogram that even the stereogram-impaired can enjoy as it’s both a stereogram and an optical illusion. The 3‑D image is a basic object-array stereogram but with the objects skewed a bit in the z dimension using the trick I discovered when developing Rotated Squares (above). In the the 2‑D image, a school of goldfish appears to move slowly in a wave pattern but is in fact quite stationary. (The optical illusion was inspired by Akiyoshi Kitaoka’s Murasaki-imo wave. I enjoy many of Prof. Kitaoka’s works.)
Straight Lines Straight Lines Following the theme of Goldfish Bowl (above), I wanted to see if I could combine stereograms with other types of optical illusions. In Straight Lines, the optical illusion is that the checkerboard pattern is perfectly straight and regular, even though it looks crooked. The 3‑D image is, alas, just a boring diamond shape. I wasn’t able to achieve the resolution needed to do better without sacrificing the optical illusion.
Room and Mushroom Room and Mushroom I had wanted to do something like this for a long time and finally figured out how. Room and Mushroom shows different 3‑D images at different zoom levels. When viewed at 100% zoom (1920✕1080 pixels), the image depicts a living room. When scaled down to 25% (the equivalent of 480✕270 pixels), the image depicts a large mushroom. The living-room images unfortunately contains some distracting coloration; use the top guides to help focus (and use the bottom guides to help focus on the mushroom). A DjVu version of Room and Mushroom lets you separately display the foreground (living room) and background (mushroom) images.
Fun and Games Fun and Games Is it possible to create a stereogram whose 2‑D image is a maze? The answer is sort of. In Fun and Games, the 3‑D image is supposed to be Pac-Man, but it’s unfortunately rather hard to identify and even rather hard to focus on. Use the ghosts at the top to help align your eyes. The 2‑D image isn’t too terrible, though. For the solution to the maze, load the SVG version of Fun and Games into Inkscape and mark the Solution layer as visible.
Ode to Quadrilaterals Ode to Quadrilaterals This stereogram shows four quadrilaterals popping out of a concave background. What’s interesting here is that the 2‑D image is itself composed entirely of quadrilaterals, all with crisp borders. An SVG version of Ode to Quadrilaterals is also available.
Cubism Bear Cubism Bear I wanted to see if it’s possible to make a stereogram in which the background pattern portrays a recognizable object, challenging the requirement that a background pattern be a repeating tile. Cubism Bear overlaps partial images of a teddy bear, as might be done in a cubist painting, to accomplish this feat.
Flower Photo Flower Photo Like Room and Mushroom (above), Flower Photo presents different 3‑D images at different zoom levels. The difference lies in the interpretation of the smaller image. When viewed at 100% zoom (1024✕768 pixels), Flower Photo is a hidden-image stereogram of a camera. When scaled down to 25% (the equivalent of 256✕192 pixels), Flower Photo changes from a hidden-image stereogram to a side-by-side stereogram (i.e., image pair) of a flower.
Two Monets Two Monets Continuing the theme of Room and Mushroom and Flower Photo (above), Two Monets represents a combination of two images. In this case, the 3‑D image is Monet’s Grainstack, Sun in the Mist, and the 2‑D image—best viewed at a distance—is Monet’s In the Garden. Although it’s a little hard to focus on the 3‑D image, Two Monets does show that it’s possible to superimpose a non-repeating 2‑D image on a stereogram without completely destroying the 3‑D effect.
Household Items Household Items The defining characteristic of a wallpaper stereogram is repeated images. But can one produce a wallpaper stereogram in which no image is repeated? Household Items is based on images morphing into each other—a pencil into an umbrella, a clock into a hat, etc.—sufficiently gradually so as not to disrupt the 3‑D effect. I’m pleased this works as well as it does.
Big Snake Mouth Big Snake Mouth A single-image stereogram’s 2‑D tiles are typically discontinuous across repetitions. The effect is particularly noticeable for tiled photographs. For Big Snake Mouth I tried to make the tiling seamless. Although successful, I had to sacrifice sudden changes in depth in the 3‑D image, which is a severe limitation.
Sombrero Sombrero This stereogram is an experiment in overlapping multiple 3‑D images at different depths. Notice how, especially near the center of the image, the red mesh is raised above the white mesh, which is raised above the green mesh. I like this effect although I don’t think I did such a great job modeling a sombrero.
Traffic Jam Traffic Jam Here, I was trying to render a traffic light with red, yellow, and green spheres floating above a gray base. After more than 40 completely failed attempts, I gave up trying to crisply separate the colors and accepted some color bleed between the lights and the base, which is what you see here. Anyway, an SVG version of Traffic Jam is also available.
Graph Graph Graph Graph Graph Graph began with an attempt to draw stereograms out of triangles but degenerated into a sophomoric play on words: a graph (vertices connected by edges) 2‑D pattern that produces a graph (bar chart) stereogram. An SVG version of Graph Graph is also available.
River Canyon River Canyon This is mainly an experiment in mixing extreme and subtle changes in depth, represented respectively by the tall cliffs and the gentle waves on the river. The color blend between the cliffs and the river worked out nicely, too.
Great Pyramid Great Pyramid Here’s my to-scale rendering of the Great Pyramid of Giza, constructed entirely from colored triangles—7488 of them, to be exact. (I initially tried modeling all three pyramids in the Giza pyramid complex, also to scale, but the 3‑D didn’t work out as well as I had hoped.) An SVG version of Great Pyramid is also available.
Desk Desk Many computer-graphics formats are based on 24-bit color: 8 bits for each of the red, green, and blue color channels for a total palette size of 28 × 28 × 28 = 16,777,216 colors. What makes Desk unique is that it uses each of those 16,777,216 colors exactly once. (Thanks to Michael Fogelman’s AllRGB script for automating the color assignment.) At 4096×4096 pixels (and 45 MB), Desk is a much larger stereogram than most of the others on this page. It’s best to view the image at full size and scroll around to see all the 3‑D items. A ray-traced, full-color version of the 3‑D model may help you identify what you’re looking for. Desk was a fun stereogram to produce because it allowed for much greater detail to be modeled than is possible with smaller images.
Sinking Ship Sinking Ship Unlike probably every other single-image stereogram ever produced, Sinking Ship is drawn with concentric circles, centered roughly in the middle of the picture. I’m pleased with how well this image came out, and I’m in fact amazed that using concentric circles instead of a horizontally repeated pattern works at all.
Pretzel Maze Pretzel Maze This stereogram revisits the question posed above by Fun and Games: Is it possible to create a stereogram whose 2‑D image is a maze? By improving upon the technique introduced with Big Snake Mouth, I was finally able to create an honest-to-goodness maze that is also an easy-to-focus-on autostereogram. (Try to navigate from the upper-left corner to the lower-right corner.) Admittedly, the maze isn’t the most interesting maze ever created, and abrupt changes in depth are lacking from the 3‑D image, but I nevertheless consider Pretzel Maze a resounding success. An SVG version of Pretzel Maze is also available.
Locks and Keys Locks and Keys Like Winter Scenes above, Locks and Keys is an attempt to conceal a 2‑D image within what looks like an ordinary random-dot stereogram. To see the hidden image this time, map the stereogram to polar coordinates. (In GIMP, use Filters→Distorts→Polar Coordinates….) Stand back a few paces, and behold!
Secret Message Secret Message Can you read the secret message? It’s a bit flickery, but look for text written vertically down the middle of the image.
Secret Message 2 Secret Message 2 Here’s an easier-to-read secret message. An SVG version of Secret Message 2 is also available.
Faces and Vases Faces and Vases Do you see pictures of faces or vases? (Look particularly at the top and bottom rows.) Here, I wanted to see if I could incorporate a Rubin vase—with my own shaggy profile— into an autostereogram. An SVG version of Faces and Vases is also available.
Rainy Night Rainy Night This started as an experiment of different depth layers (a bit like Sombrero, above), but I was unable to make it work as intended. In the end, I removed the fancy stuff, leaving only the pleasant, if ordinary, stereogram you see here. An SVG version of Rainy Night is also available.
Black Hole Black Hole Black Hole is more like what I was originally shooting for with Rainy Day, above. Note how the 1000+ stars depicted in this image appear in 3‑D at such a wide variety of depths. The nearby stars at the edges of the image are somewhat cluttered, making them a bit hard to focus on, but the stars in the center are quite crisp. An SVG version of Black Hole is also available.
Herringbone Necktie Herringbone Necktie One problem with single-image autostereograms is that the 2‑D image’s tile pattern normally winds up being discontinuous in spots. Contrast Herringbone Necktie with what it would have looked like with typical stereogram-generating software. Notice how the thick, diagonal lines in Herringbone Necktie are preserved—with some distortion but no disjointedness—across the entire 2‑D image. In contrast, the alternative version presents a crisper 3‑D but at the cost of a more broken 2‑D.
How to Design an Autostereogram How to Design an Autostereogram This idea was too cute to pass up: a flowchart showing how to design an autostereogram. You start with the basic concept, then use 3‑D modeling software to produce a grayscale depth map. If this looks good, you create a 2‑D tiling pattern. Once you’re happy with that, the next step is to produce the autostereogram from the depth map and the tiling pattern. If the result is hard to focus on, a different tiling pattern may help. Sometimes, the autostereogram works fine but is simply uninteresting, in which case you start all over. An SVG version of How to Design an Autostereogram is also available.
Turtles All the Way Down Turtles All the Way Down Can one create a stereogram in which the 2‑D tiling pattern is another stereogram? Why not? Turtles All the Way Down depicts a 3‑D turtle. Zoom in to 800% to see that each tile is a stereogram of the same 3‑D turtle, itself tiled by little, colored 2‑D turtles. I’d recommend downloading the large JPEG version of Turtles All the Way Down (18 MB) or the large DjVu version (10 MB). At 8192×6144 pixels, these are substantially crisper than the 1024×768 version. In either case, the top and bottom of the image are the least distorted so zoom in there first.
Pool Table Pool Table In the past, I’ve observed that if the near-plane and far-plane repetition distances in pixels exceed a 2:1 ratio, the 3‑D image is hard to perceive. Pool Table uses a 6:1 ratio globally but ensures that very near and very far objects are not placed close to each other. The result is a stereogram that exhibits quite a range of depth. The colors at the top of the image repeat every 200 pixels while the pixels at the bottom of the image repeat only every 30 pixels. Contrast this to a version of Pool Table with more typical far-plane/near-plane separation—repetition distances ranging from 102 to 128 pixels, as is used in many of the images on this page. (I sometimes go to 85–128 but rarely beyond that range.)
Apple Tree Apple Tree This is a stereogram of a stylized apple tree. What makes it interesting is that it is composed entirely of differently colored and differently scaled ellipses. An SVG version of Apple Tree is also available.
Kilroy Was Here Kilroy Was Here This isn’t my best 3‑D, but if you stare enough at the bottom half of the image you should be able to perceive Kilroy and his elongated proboscis peering over a wall. More interesting, however, is the 2‑D image of an impossible trident. Note how the ten rectangular prongs at the bottom blend into twelve cylindrical prongs (plus a few off-screen) at the top.
Jailbirds Jailbirds Here’s another stereogram that can also be enjoyed by the stereogram-impaired. Either print out the image and cut it on the dashed lines into three pieces or view the interactive, online version of Jailbirds. Count the number of rectangles. You should get 28. Now swap the top two pieces and count again. This time, there are only 27! Where did the 28th rectangle go? Also, note that the stereogram works in both the original and rearranged configurations. Neat, huh?
Eye Eye Can a stereogram establish its 3‑D image out of negative space? My best answer so far is yes, but with very low resolution. Eye comprises a set of thick, colored lines that are evenly spaced horizontally, but carefully placed gaps define a cartoon eye when viewed wall-eyed. An SVG version of Eye is also available.
Ring of Sauron Ring of Sauron There’s a lot going on in this text stereogram. First, it comprises exclusively valid English words. (I had to rely on a fair number of those dubious two-letter Scrabble words, though.) Second, the lines of the One Ring’s inscription appear alternately on the left and right. Third, a 3‑D annulus pops out of the main part of the image. Fourth, the caption, the one ring pops out of the bottom part of the image. A plain-text version of Ring of Sauron is also available.
Rock Cairns Rock Cairns Although he creates a lot of great stereograms, 3Dimka’s solid-array photostereograms such as Emperor Penguins and Shamrock are my favorites and inspired me to try to construct a photostereogram of my own. I began with a photograph I took at Mile Rock Beach (San Francisco, California, USA), made a vertical strip of it tileable, and manually constructed a depth map rock-by-rock. I consider the result not too bad for a first attempt.
Number One Number One This simple mapped-texture stereogram is in fact the product of some sophisticated software. I started with (poorly aligned) left-eye and right-eye smartphone photographs of my own hand and arm, inferred a depth map from these, and used the original images to smoothly texture a stereogram generated from that depth map.
Upward Shapes Upward Shapes Like Rotated Squares and Sinking Ship, Upward Shapes fits in the How does this even work? category. It’s an object-array stereogram in which the objects are laid out at a slight upward angle (5°) instead of horizontally. Strangely, the 3‑D effect still works.
Self Stereo Self Stereo An object-array stereogram typically comprises one or more objects that repeat at varying intervals to produce the illusion of depth. Self Stereo is an experiment in using a single, solid-looking object that itself consists of a repeated pattern. The single-object construction turned out to be less impressive than I had hoped, but the 3‑D effect involving the solid structure came out fine.
Bottle and Fishes 3‑D Bottle and Fishes 3‑D As an initial test of some new software I wrote for generating mapped-texture stereograms, I tried producing a stereogram version of Georges Braque’s Bouteille et Poissons. It doesn’t look as much like the original as I had hoped, but the 3‑D image is reasonable easy to perceive.
Bowling Ball and Pin Bowling Ball and Pin In 2016 a book publisher wrote to me, asking if I could author a stereogram coloring book for them. I said no because (a) I had no idea how to produce a color-your-own stereogram and (b) they wanted 48 images, which would have taken me an eternity to produce. With Bowling Ball and Pin (also available in SVG and PDF), I’ve at least addressed issue (a). A sample coloring (also available in SVG) shows what the result might look like.
Lava Lamp Lava Lamp What colors do you see in this image? Amazingly, the image uses only pure red, pure green, pure blue, and light gray—plus a black outline around each shape. Zoom in if you don’t believe me! This effect, in which our perception of color is influenced by surrounding colors, is known as the Munker-White illusion or the Bezold effect. An SVG version of Lava Lamp is also available.
Balloons Above the City Balloons Above the City This stereogram enhances the basic mechanism employed by Self Stereo with a more varied 3‑D view. I really like how the buildings all appear to have the same height in the 2‑D image but different heights in the 3‑D image. (As an aside, no one will ever hire me as a city planner because I’d insist that buildings form a stereogram when viewed from above. 😀)
Ghost in the Doorway Ghost in the Doorway I’ve long struggled to find a way to include transparent objects without making the 3‑D hard to focus on. Ghost in the Doorway is my best attempt so far. The intention is for the ghost to be only partially visible but the doorway to look solid. I think this came out reasonably well given the difficulty of the task.
Eyeglasses Eyeglasses Can a stereogram’s 2‑D image transition between crisp and blurry without disrupting the 3‑D image? Eyeglasses indicates that the answer is yes. Notice how the background is very blurry, the frames of the eyeglasses are slightly blurry, and the view through the lenses is perfectly crisp. Nifty, eh?
Willis Tower Willis Tower This stereogram, of Chicago’s Willis Tower (or Sears Tower, as it was called when I was growing up), implements a similar concept to Empty Table, above: varying brightness within an image. In Empty Table, the shadow spreads evenly throughout the picture. Here, I wanted to see if I could localize the shadow to the central 3‑D object. It was also an interesting challenge to devise a 2‑D texture that draws out the boxy structure of Willis Tower within a stereogram’s low effective resolution.
Pair of Shoes Pair of Shoes I wanted to see if I could construct a stereogram entirely of horizontal and vertical lines—no curves and no diagonals. These lines further form a single path with no self-intersections (à la String Theory, above). An SVG version of Pair of Shoes is also available.
Sea Star on the Sand Sea Star on the Sand What makes this stereogram unique is the 2‑D texture. Inspired by the album art for Soulwax’s Any Minute Now, it portrays the word STAR when viewed at a distance. (I find it’s easier to perceive when viewed at an angle of about 45°.)
Stacked Blocks Stacked Blocks This stereogram shares a bit in common with Sinking Ship and Eyeglasses above. In the case of Stacked Blocks, the 2‑D texture is crisp in the horizontal center of the image but becomes increasingly pixelated toward the left and right edges. Because the basic coloring is preserved as single pixels morph into 2×2 regions then 4×4, 8×8, 16×16, and finally 32×32, the image is relatively easy to perceive apart from the leftmost and rightmost blocks.
As American as Apple Pie As American as Apple Pie You may have noticed that String Theory and Pair of Shoes use a line that zigs and zags alternately top-to-bottom and bottom-to-top. I wondered if it would be possible instead to meander alternately left-to-right and right-to-left. It is! However, in the interest of producing a more aesthetically pleasing stereogram, I ended up forgoing the single-line technique for As American as Apple Pie. Instead, I drew a number of wavy horizontal lines, colored the interstitial space, and tossed in some stars to produce a reasonably accurate American flag. An SVG version of As American as Apple Pie is also available.
Trigonometry Trigonometry I had long thought about constructing a mathematical function that can be viewed as a stereogram when plotted. My early attempts were based on interpolation, but this led to excessively complex, numerically unstable functions. The function plotted in Trigonometry was constructed manually and is much, much simpler: cos(10𝜋(1−|x|)5/4). The downside is that the 3‑D image is also disappointingly simple. An SVG version of Trigonometry is also available.
Tetrominoes Tetrominoes Here’s an object-array stereogram of the five free tetrominoes (think Tetris), rendered using transparent glass versions of the eight tetracubes. What worked: intersecting transparent objects. What didn’t work and was therefore removed from the final image: larger objects (too hard to discern the 3‑D image) and shadows (too distracting). Contrast Tetrominoes with an earlier version and see for yourself.
Crisscross Crisscross I stumbled across the effect used in this animated (20-second loop) object-array stereogram by accident. When viewed in 3‑D, the cyan stripes appear on top, the magenta stripes on bottom, and the yellow circles between them. If the yellow circles are removed, the cyan and magenta stripes appear to lie in the same plane. Weird, huh? An SVG version of Crisscross with nicer, smoother animation is also available.
Shampoo and Conditioner Shampoo and Conditioner This is my first attempt at creating a contour stereogram so I intentionally kept it a bit simple. I slightly darkened the back side of each bottle, which is a subtle but pleasant effect. An SVG version of Shampoo and Conditioner is also available.
Snow Globe Snow Globe Some of the best stereogram artists superimpose contours atop conventional or mapped-texture stereograms to expose details in the 3‑D model and make the overall image easier to perceive. (Contrast Snow Globe with no contours and no mapped textures.) The idea in Snow Globe, which I don’t believe I’ve seen previously, is additionally to use contours to delineate transparent regions, in this case the globe itself. I’m glad that the snowflakes are quite visible—I was worried that they wouldn’t show up, and I’d have a snowless snow globe.
Dalí Hypercubus Dalí Hypercubus I’ve been trying to improve upon the technique used above in Big Snake Mouth and Pretzel Maze, in which a stereogram is produced by warping a tiled image. The goal is to avoid ugly discontinuities in the 2‑D image. Dalí Hypercubus is not yet perfect—the edges in the 3‑D image aren’t as crisp as they ought to be—but it is an improvement. In particular, the new technique supports sudden changes in depth, which prior techniques did not. The stereogram name refers to Salvador Dalí’s Corpus Hypercubus, and the 2‑D image comprises photographs and self-portraits of Dalí.
The Land of Ribbons The Land of Ribbons This stereogram depicts a stylized hill, cloud, and sun. each defined by a single, colored ribbon. The interesting bit is how the white ribbon comes to the front to form the cloud then recedes so the yellow ribbon can come to the front to form the sun.
Duck Shoot Duck Shoot A number of Gene Levine’s stereograms embed a stereogram within non-stereogram surroundings, which makes it non-obvious that the image is in fact a stereogram. I wanted to try that trick myself. As a bonus, I rendered the 3‑D image using a combination of a SIRDS, a contour stereogram, and a cloud (small-object) stereogram.
Watering Can Watering Can The 2‑D image seen here, derived from Renoir’s A Girl with a Watering Can, is what Øyvind Kolås has dubbed a color assimilation grid illusion. That is, while the image appears to be a bit faded but colored more-or-less normally (especially when viewed at a distance), it is in fact 88% gray—your brain is filling in the missing colors. It’s nice that the effect works fine even though the colored-hatch pattern is a bit distorted due to the stereogram.
Funhouse Mirrors Funhouse Mirrors I’m still trying to improve my techniques for minimizing horizontal discontinuities in a stereogram’s 2‑D image. Here you see my latest attempt. Although I’m pleased with the 2‑D view, I still haven’t managed simultaneously to include sufficiently sharp edges in the 3‑D image. To clarify, I refer you to a conventional rendering of Funhouse Mirrors in which the 3‑D view is nice and crisp, but the 2‑D view chops segments out of the people (most noticeably with the male models).
Japanese Teapot Japanese Teapot I know you’re tiring of hearing me say this, but I’m still trying to improve my techniques for minimizing horizontal discontinuities in a stereogram’s 2‑D image. I’ve been making good progress, as you can see by the lack of distracting, sharp, vertical lines in the 2‑D image shown here (a tiled derivative of Hiroshige’s View of the Whirlpools at Awa). Pixels are stretched and squashed, rather than kept or discarded, to form the 3‑D image. I’ve also produced a new Dalí Hypercubus and a new Funhouse Mirrors. Contrast the smoothness of the old and new 2‑D images and the sharpness of the edges in the old and new 3‑D images.
Palette and Brush Palette and Brush What’s the narrowest 2‑D tile that still leads to a perceptible 3‑D image? More formally, what are the minimum pixel widths of an autostereogram’s near and far planes? I was able to go as low as 21 pixels on the near plane and 32 on the far plane, as used in the image presented here. (I included guides at the top to help my eyes diverge the desired amount, but it’s still not easy. How do your eyes fare?) I also created a WebP animation of Palette and Brush, which repeatedly varies the near/far separation from 85/128 down to 21/32 and back. Note that only the 2‑D is stretching and squashing. Changes in the width of the 3‑D image are an optical illusion.
Cat and Mouse Cat and Mouse Does rendering a stereogram with a halftoning pattern make the 3‑D image hard to perceive? Answer: no. In fact, this is actually one of my clearer works. An SVG version of Cat and Mouse, comprising 31,510 little, black circles, is also available.
Theater Masks Theater Masks Is it possible to encode different stereograms into an image’s different color channels? I considered specifically the HCL color space, encoding different stereograms in the hue, chroma, and lightness channels. What I discovered is that only the lightness stereogram, a comedy mask, is visible. But be sure to watch the Theater Masks video, in which I gradually set lightness to a uniform value, which makes the hue stereogram, a tragedy mask, visible. Then I gradually set hue to a uniform value, making the chroma stereogram, a star, visible.
Two Jack-o’-Lanterns Two Jack-o’-Lanterns The shadow on the green ribbon in The Land of Ribbons above got me thinking: Could one construct an object-array stereogram in which the objects’ shadows form the 3‑D image? In Two Jack-o’-Lanterns, the left jack-o’-lantern is composed from shadows lying behind a flat wall of objects. The right jack-o’-lantern is the opposite, composed from objects lying in front of a flat wall of shadows. An SVG version of Two Jack-o’-Lanterns is also available.
Transparent Egg Transparent Egg Lovesick, above, combines front and back stereograms for a richer 3‑D effect. I began wondering if more than two stereograms could be combined in that manner. Transparent Egg depicts an egg with separate stereograms for the front and back of the shell and the front and back of the yolk. I’ll claim a partial success on this one. All four components are indeed visible, but they’re a bit hard to perceive in places. An SVG version of Transparent Egg is also available.
Camping Tent Camping Tent Can one create a stereogram that is also a connect-the-dots puzzle? The answer is yes, but with qualifications. Try as I might, I was unable to achieve my goal of producing a dot pattern that would not reveal the hidden image until the dots were connected. Consequently, the solution adds little to the unsolved variant. An SVG version of Camping Tent and its solution are also available.
Camouflage Camouflage A hidden-image stereogram employs slight variations in a repeated pattern to hide a 3‑D object. An object-array stereogram, in contrast, repeats a visible object at different distances to make the object instances appear at different depths. Camouflage is unique in that it is an object-array stereogram in which the repeated object (a military rifle) is not visible—because it’s camouflaged against the background. I’m pleased with how this stereogram turned out.
Hats Hats Stained-glass stereograms are among the easiest types of autostereograms to perceive and a great choice for beginners. My plan is to improve automation of the process of producing this type of stereogram. Hats is a largely manual effort I undertook to get a feel for the touch-ups I eventually want the computer to perform.
Fish Tank Fish Tank The idea here was to see what would happen if I overlaid a transparent object-array stereogram atop a random-dot stereogram such that the visible objects in the former cut through the hidden object in the latter. Would the hidden object appear partially transparent? The answer is sort of. I find the effect more distracting than pleasing, and I also find it hard to gauge the relative depths of some of the individual objects. Oh, well; it was worth a try.
Space Invaders Space Invaders An object-array stereogram normally constructs a 3‑D effect by repeating an object at different horizontal intervals. Space Invaders is unique in that the objects are (mostly) evenly spaced—see the underlying grid—but are altered slightly so that some objects appear to pop out while the rest appear flat. As the alien ships form only an 11×6 grid of pixels there’s not enough resolution to draw more than simple geometric shapes so don’t expect anything too fancy here.
Swarm of Bees Swarm of Bees I finally figured out why the 3‑D for the toys in Child’s Play, above, appears a bit off: When 3‑D floaters are used in an object-array stereogram, they have to be rotated in the opposite direction from an ordinary perspective rendering. Swarm of Bees correctly rotates the bees so that each bee displays proper depth when viewed wall-eyed.
X Marks the Spot X Marks the Spot The objects in an object-array stereogram normally span the width of the image. This made me wonder if it would be possible for the objects not to span the width of the image but rather to fade out after a few repetitions. I find the effect works better for the contiguous objects near the center of the X than for the sets of objects near the top and bottom of the X that fade out and fade in again.
Bunch of Bananas Bunch of Bananas This is an experiment to see if I could construct a random-dot stereogram in which only one color pops up and the rest form the background. (From the stereogram title you can probably guess which color is special. 😀) Being made of speckles, the 3‑D object is not fully solid, but I find that it is reasonably recognizable.
Acorn Acorn A visitor to this site asked about very, very small stereograms. Acorn is my attempt to produce a 100×100-pixel random-dot stereogram—a bit larger than a typical postage stamp. The 3‑D is a bit hard to focus on, and it may not obviously appear to be an acorn, but I hope you can see that there’s something present in the image. If you give up, a full-size version of Acorn (1000×1000 pixels) is also available.
Driving Accident Driving Accident This stereogram is essentially a more sophisticated version of Sombrero, above. The technical approach was to construct an object-array stereogram of a warped plane from individual points rather than complete objects then to connect those points in a lattice to produce a seamless fence. This solid-array stereogram is overlaid atop both a contour stereogram and a patterned stereogram of a car.
Desperation Desperation Desperation is similar in spirit to Two Monets above but with an attempt to make the 3‑D image (a noose hanging from the ceiling) a bit more perceptible by drawing it as a SIRDS with a visible diagonal-line bias and by reducing the contrast of the overlaid 2‑D image (Courbet’s Le Désespéré). This helps, but there remains a lot of room for improvement.
Secret Message 3 Secret Message 3 Here’s another flickery stereogram; sorry. Like Secret Message and Secret Message 2 above, the challenge is to see if you can read the hidden word. The experiment I’m performing is to see if an object-array stereogram can split its objects into thirds and let the viewer’s eye recombine them. An SVG version of Secret Message 3 is also available.
Petri Dish Petri Dish This is an object-array stereogram that uses one set of shapes for the foreground and one for the background, but—and this is what makes Petri Dish unique—merges foreground and background shapes when they overlap. Thus, individual shapes can contribute to both the foreground and the background layers. Furthermore, object merging leads to less exact repetition than in a conventional object-array stereogram. An SVG version of Petri Dish is also available.
Barn and Silo Barn and Silo This image furthers the technique developed for Land of Ribbons above by employing multiple shades of color to more clearly disambiguate side-by-side objects, in this case a red barn and a gray silo. I would have liked to have been able to make the objects denser (using more vertical lines) to make them more easily perceptible, but that would have made it harder to distinguish the two objects. An SVG version of Barn and Silo is also available.
Noah’s Ark Noah’s Ark This is a rather mundane stereogram of an ark. What’s noteworthy is the software used to produce it: I used libmorph to warp a regularly tiled pattern into the stereogram you see here. Why is that interesting? Because the same mechanism can be used to smoothly morph one 3‑D image into another as in this Noah’s Ark morphing stereogram video (q.v.).
Shower Stall Shower Stall This represents a new approach to including transparent objects in a stereogram. I encoded the transparent objects using only the hue and chroma color channels, not the lightness color channel. This makes it possible to see through the glass face of the shower stall into the opaque interior (which contains just a bench). I like this approach and might reuse it in the future.
Lighthouse Lighthouse Here’s a stereogram of a lighthouse that encodes a secret message. Unlike Secret Message, Secret Message 2, and Secret Message 3 above, the message is encoded in the 2‑D image, not the 3‑D image. Hence, even people who can’t perceive stereograms can enjoy this puzzle. Hint #1: Read down the center column. Hint #2: Look in the negative space. Hint #3: Try squinting/closing your eyes partway. An SVG version of Lighthouse is also available.
Scissors Scissors Most stained-glass stereograms delineate their 3‑D objects with contour lines. Doing so facilitates perception of the 3‑D objects, especially small or thin objects. My goal in creating the Scissors stereogram was to achieve a comparable effect using only abrupt color changes—no contour lines. I think the stereogram came out pretty crisp, don’t you?
Bell, Book, and Candle Bell, Book, and Candle The idea here was to see if I could create a stereogram that looks like an object-array stereogram, but only one instance of each identifiable object pops out in 3‑D; the rest blend into the smooth background object. I claim success in achieving that effect.
Zebra Zebra Ilja Klemencov's “They can disappear” hides the WWF's panda logo within a zigzag pattern. Although I was able to mimic this effect in a self portrait (try viewing it at an angle), I wondered if I similarly could hide a stereogram. After a number of attempts I concluded, “Yes, but not as nicely”. Zebra is a stereogram comprising 176 evenly spaced zigzags in which the pen thickness varies substantially—I was aiming for subtly—as the line moves down the page. An SVG version of Zebra is also available.
House with Fence House with Fence The fence in this stereogram's foreground is in fact a hidden message (in 2‑D). View the image from the bottom at a very shallow angle or, alternatively, save the image to a file and use your favorite image editor to scale it down to 70 pixels tall while retaining the existing width.

These stereograms were created using a variety of open-source tools plus numerous custom programs and scripts. See image and font credits for acknowledgments of material created by others that I incorporated into my stereograms.

Commons License All images are Copyright © 2009–2024 Scott Pakin and are licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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