aparler/RosettaCodeData
1
0
Fork 0
Code Issues 12 Pull requests 3 Projects Releases Packages Wiki Activity Actions

Data update

Browse source
This commit is contained in:
Ingy döt Net 2026-04-30 12:34:36 -04:00
parent 4bb20c9b71
commit cbaf4c4b64
12390 changed files with 318560 additions and 27248 deletions
Download patch file Download diff file Expand all files Collapse all files

27
Task/Bitmap-Histogram/Rebol/bitmap-histogram-1.rebol Normal file
View file

@ -0,0 +1,27 @@
Rebol [
title: "Rosetta code: Bitmap/Histogram"
file: %Bitmap-Histogram.r3
url: https://rosettacode.org/wiki/Bitmap/Bitmap-Histogram
needs: 3.21.9
]
;; Load source image from file
img: load %Lenna50.jpg
;; Extract luminosity as vector for statistical operations
vec: to vector! img/luminosity
;; Compute median brightness threshold
med: vec/median
;; Allocate 256-bucket uint32 histogram (one bucket per brightness level)
histogram: make vector! [uint32! 255]
;; In a single pass: build brightness histogram and threshold each pixel
forall vec [
val: vec/1
histogram/:val: histogram/:val + 1 ;; tally pixel's brightness bucket
vec/1: either val < med [0][255] ;; binarize: black or white
]
;; Inspect histogram distribution
? histogram
;; Write thresholded grayscale data back to image
img/gray: vec
;; Save result as PNG and open in browser
browse save %Lenna50-bw.png img

8
Task/Bitmap-Histogram/Rebol/bitmap-histogram-2.rebol Normal file
View file

@ -0,0 +1,8 @@
img: load %Lenna50.jpg
foreach channel [red green blue] [
vec: to vector! img/:channel
med: vec/median
forall vec [vec/1: either vec/1 < med [0][255]]
img/:channel: vec
]
browse save %Lenna50-rgb.png img