# Tag Info

Accepted

### Upgoat or Downgoat?

Mathematica, 100%, 141 bytes ...
• 4,605

### Upgoat or Downgoat?

JavaScript, 93.9% ...
• 11.2k

### Upgoat or Downgoat?

Java, 93.9% 100% This works by determining the row contrast in the upper and lower part of the image. I assume that the contrast in the bottom half of the image is bigger for 2 reasons: the 4 legs ...
• 2,912

### Patch the Image

Matlab This is a simple interpolation approach. The idea is first mirroring what is on each side of the patch. Then those mirror image pixels are interpolated by how close they are to the ...
• 43.7k

### Upgoat or Downgoat?

Python 3, 91.6% -edited with the new test cases set filename to the goat picture you wish to test. It uses a kernel to make an image top/bottom asymmetric.I tried the sobel operator, but this was ...
• 1,362
Accepted

### Determining vertical slices

Jelly, 2 bytes PS Try it here! If I encode an image like so: ...
• 68.1k
Accepted

### Black and White Rainbows

Matlab, 255 245 231 bytes This expects the image name first, then y and then x. ...
• 43.7k

### Computer Generated Cracked Soil

Mathematica A Voronoi diagram looks like this drawing, from Wikipedia, showing 19 cells, each containing a single seed point. A cell consists of the subregion of points which the respective ...
• 25.3k

### Paint by Numbers (using programming, not numbers)

Spectral airbrushing (Python, PIL, scipy) This uses a sophisticated mathematical algorithm to produce colourful nonsense. The algorithm is related to Google's PageRank algorithm, but for pixels ...
• 7,232

### Invert png image

ImageMagick display -fx, 3 7 18 24 bytes 1-u The ImageMagick tool display with the ...
• 6,048

### Upgoat or Downgoat?

Python 3, OpenCV with Hough Transform, 100% My original idea was to detect the vertical lines of the goat's legs and determine its vertical position relative to the body and horizon. As it turns out, ...
• 11.5k

### Computer Generated Cracked Soil

Java I used an approach based on recursive Voronoi diagrams. The outputs doesn't look very realistic, but I guess they're okay. Here are some example images (resized to 250x250 so that it doesn't ...
• 8,102

### Paint by Numbers (using programming, not numbers)

Python 2 + PIL too, my first coloring book ...
• 2,038

### Patch the Image

Mathematica This uses Mathematica's Inpaint function. Because Mathematica itself does all the heavy lifting, this is a community wiki. ...

### Paint by Numbers (using programming, not numbers)

Python 2 and PIL: Psychedelic Worlds I have used a simple algorithm to flood fill each white-ish area with a color from a cycling palette. The result is very colorful, but not very lifelike. Note ...
• 6,762
Accepted

### Sort the pixels

Pyth - 10 bytes Reads image, collapses bitmap, sorts, and then splits up bitmap again, then writes. .wclK'zSsK Doesn't work online for obvious reasons. Takes input ...
• 25.7k

### Invert png image

Pyth, 16 15 13 bytes .w-LLL255'z\a Outputs to a.png. ...
• 71.4k

### Patch the Image

Python 2 and PIL This program blends copies of regions North, South, East, and West to create replacement pixels that use colours, textures, and shading from the local image region. The example ...
• 6,762

### XOR two monochrome images

The Fx Expression Language (ImageMagick), 8 4 bytes EDITS Simplified to u!=v, -4 bytes As "Fx Expression Language" is apparently Turing complete, I've ...
• 8,476

### Sort the pixels

JavaScript (ES6), 383 377 354 bytes ...
• 3,702

### Fill the holes in letters

Bash, 135 bytes convert +antialias -pointsize 99 label:\$1 -fill red -draw 'color 0,0 floodfill' -fill black -opaque white -fill white -opaque red i.png Uses ...
• 71.4k

### Invert png image

MATL, 10 bytes 255iYi-IYG There are five different subformats of PNG, depending on how color is encoded. None of them seems to be more "optional" than the others....
• 104k
Accepted

### Reconstruct a missing RGB channel

Python 3 + scikit-image Simply sets the color of the missing channel to the average of the other two. ...
• 39k
Accepted

### Where's Blackhat?

PHP (>=7), 100% (40/40) ...
• 5,947

Java, 295 ...

### Upgoat or Downgoat?

Python 3, numpy, scikit, 100% This code runs a goat-trained image classifier against a single filename, printing out 'Upgoat' or 'Downgoat'. The code itself is one line of python3, preceded by a ...
• 1,305

### XOR two monochrome images

Mathematica, 37 34 15 bytes Thanks to Ian Miller for cutting the number of bytes by more than half! ImageDifference In the end, there's always a builtin. This ...
• 15.4k