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dsparks/voronoi_raster.R

Created October 30, 2012 15:41
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  1. dsparks created this gist Oct 30, 2012.
    59 changes: 59 additions & 0 deletions voronoi_raster.R
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    doInstall <- TRUE # Change to FALSE if you don't want packages installed.
    toInstall <- c("ReadImages", "reshape", "ggplot2")
    if(doInstall){install.packages(toInstall, repos = "http://cran.r-project.org")}
    lapply(toInstall, library, character.only = TRUE)

    # Image URL:
    allImageURLs <- c("http://media.charlesleifer.com/blog/photos/thumbnails/akira_940x700.jpg",
    "http://upload.wikimedia.org/wikipedia/commons/thumb/e/ec/Mona_Lisa%2C_by_Leonardo_da_Vinci%2C_from_C2RMF_retouched.jpg/402px-Mona_Lisa%2C_by_Leonardo_da_Vinci%2C_from_C2RMF_retouched.jpg",
    "http://upload.wikimedia.org/wikipedia/commons/thumb/e/e9/Official_portrait_of_Barack_Obama.jpg/441px-Official_portrait_of_Barack_Obama.jpg",
    "http://cache.boston.com/universal/site_graphics/blogs/bigpicture/obama_11_05/obama22_16604051.jpg",
    "http://upload.wikimedia.org/wikipedia/commons/thumb/e/ea/Van_Gogh_-_Starry_Night_-_Google_Art_Project.jpg/758px-Van_Gogh_-_Starry_Night_-_Google_Art_Project.jpg",
    "http://www.10mfh.com/wp-content/uploads/2011/09/dino_riders.jpg",
    "http://images3.alphacoders.com/855/8557.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/ngm_101912/bp19.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/ngm_101912/bp26.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/ngm_101912/bp35.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/balloon/bp6.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/smithsonian_030512/bp14.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/smithsonian_030512/bp15.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/earth_day_2012/bp6.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/2011part2/bp1.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/2011part2/bp4.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/2011part2/bp15.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/2011part2/bp27.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/natural_world_2011/bp40.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/ngmphotocontest_111811/bp10.jpg",
    "http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/ngmphotocontest_111811/bp54.jpg")

    imageLoader <- function(url){ # This function takes a URL, and generates a data.frame with pixel locations and colors
    # Download to disk, load
    download.file(url, "tempPicture.jpg", mode = "wb") # Stash image locally
    readImage <- read.jpeg("tempPicture.jpg")

    longImage <- melt(readImage)
    rgbImage <- reshape(longImage, timevar = "X3",
    idvar = c("X1", "X2"), direction = "wide")
    rgbImage$X1 <- -rgbImage$X1
    return(rgbImage)
    }

    ##########
    # Part 3 # Completely, unbelievably awesome Voronoi clusters:
    ##########

    rgbImage <- imageLoader(allImageURLs[5]) # Pick one, or use your own URL.

    nRegions <- 500 # Number of voronoi regions, large numbers are slow.
    voronoiMeans <- kmeans(rgbImage, centers = nRegions, iter.max = 50)
    voronoiColor <- voronoiMeans$centers[voronoiMeans$cluster, 3:5]
    with(rgbImage, plot(X2, X1, col = rgb(voronoiColor), asp = 1, pch = "."))

    rgbImage <- imageLoader(allImageURLs[5]) # Pick one, or use your own URL.
    rgbImage[, 1:2] <- sweep(rgbImage[, 1:2], 2, apply(abs(rgbImage[, 1:2]), 2, max), "/")
    rgbImage[, 1:2] <- rgbImage[, 1:2] * 1

    nRegions <- 100 # Number of voronoi regions, large numbers are slow.
    voronoiMeans <- kmeans(rgbImage, centers = nRegions, iter.max = 50)
    voronoiColor <- voronoiMeans$centers[voronoiMeans$cluster, 3:5]
    with(rgbImage, plot(X2, X1, col = rgb(voronoiColor), asp = 1, pch = "."))