.---.                                           
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 \        .'```'.    '..--.              /     .-''"'-.  `.|   |            .|  /     .-''"'-.  `..-,.--.  
  \      |       \     |  |____     ____/     /________\   |   |   __     .' |_/     /________\   |  .-. | 
   |     |        |    |  `.   \  .'    |                  |   |.:--.'. .'     |                  | |  | | 
   |      \      /    .|  | `.  `'    .'\    .-------------|   / |   \ '--.  .-\    .-------------| |  | | 
   |     |\`'-.-'   .' |  |   '.    .'   \    '-.____...---|   `" __ | |  |  |  \    '-.____...---| |  '-  
   |     | '-....-'`   |__|   .'     `.   `.             .'|   |.'.''| |  |  |   `.             .'| |      
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'-----------'             .'   /    `.   `.                    \ \._,\ '/ |   /                   |_|      
                         '----'       '----'                    `--'  `"  `'-'                             

A small R script that pixelates images

parameters

pixelate an image

positional arguments:
  input_file            name of input image file
  output_file           base name of output image file

flags:
  -h, --help            show this help message and exit
  -v, --verbose         print stuff

optional arguments:
  -x, --opts            RDS file containing argument values
  -r, --resolution      decrease input image resolution [default: 1000]
  -n, --n               number of gridpoints in each direction
                        [default: 100]
  -g, --gradient_start  color gradient start [default: grey20]
  --gradient_end        color gradient end [default: grey80]
  -b, --breaks          the number of breaks in color scale [default:
                        7]
  --geom                geometry type (raster, polygon, point, ...)
                        [default: raster]
  --height              output image height in inches [default: 7]
  -w, --width           output image width in inches [default: 7]
  -d, --dpi             output image dpi [default: 300]

example

default parameters

Rscript code/pixelate_image_v0.2.R misc/R_logo.png misc/R_logo_pixelate.jpg

Pixelater

Pixelater is an R package that generates pixelated images from input raster files. It is designed for artists and creative individuals who may not have a deep background in computer science but would like to create unique, pixelated images from their work.

Installation

Before using Pixelater, you need to install the required libraries. You can do this by running the following code in your R console:

if (!require("pacman")) install.packages("pacman")
pacman::p_load(tidyverse, raster, ggplot2, argparser, gtools, tools)

Overview of arguments

There are two required arguments and several optional arguments:

Required arguments

input_file: Name of the input image file.
output_file: Base name of the output image file.

Optional arguments

--verbose: Prints additional information during execution.
--exportRDS: Exports the ggplot object as an RDS file for downstream processing.
--resolution: Decreases the input image resolution (default: 1e3).
--n: Number of grid points in each direction (default: 100).
--gradient_start: Color gradient start (default: "grey20").
--gradient_end: Color gradient end (default: "grey80").
--breaks: Number of breaks in the color scale (default: 7).
--geom: Geometry type for the output image (options: "raster", "polygon", "point"; default: "raster").
--height: Output image height in inches (default: 7).
--width: Output image width in inches (default: 7).
--dpi: Output image dpi (default: 300).

High-level description of functions

The code is organized into a driver script and a set of utility functions:

driver_script.R: Handles user arguments and runs the main functions. utils.R: Contains utility functions for generating and saving the pixelated image.

Key functions

add_arguments_to_parser: Adds command line arguments to the parser. gplot_data: Transforms raster data into a data frame for use with ggplot. generate_pixelated_image: Generates the pixelated image based on user arguments. create_output_image: Creates the output image using ggplot. save_output_image: Saves the output image as a file. save_ggplot_as_rds: Saves the ggplot object as an RDS file. print_execution_time: Prints the time taken for the script to execute. Please refer to the code comments in the driver script and utility functions for more details on how each function works.

custom parameters

Rscript code/pixelate_image_v0.2.R misc/R_logo.png misc/R_logo_pixelate_fancy.jpg --n 25 --gradient_start "limegreen" --gradient_end "navyblue"

Rscript code/pixelate_image_v0.2.R misc/R_logo.png misc/R_logo_pixelate_breaks_10.jpg -n 50 --gradient_start "black" --gradient_end "white" --breaks 10

Rscript code/pixelate_image_v0.2.R misc/R_logo.png misc/R_logo_pixelate_breaks_5.jpg -n 50 --gradient_start "black" --gradient_end "white" --breaks 5

Rscript code/pixelate_image_v0.2.R misc/R_logo.png misc/r_logo_pix_polygon.jpg --geom "polygon" --breaks 8

Rscript code/pixelate_image_v0.2.R misc/R_logo.png misc/r_logo_point.jpg --geom "point" --height 17 --width 17