From ba5de2df95772e69b6be11be1fd4ec5b1ad026c5 Mon Sep 17 00:00:00 2001
From: Stephen D <webmaster@scd31.com>
Date: Fri, 14 Mar 2025 22:23:39 -0400
Subject: [PATCH] pixel interpolation and correct for y flip
---
src/main.rs | 45 +++++++++++++++++++++++++--------------------
1 file changed, 25 insertions(+), 20 deletions(-)
diff --git a/src/main.rs b/src/main.rs
index 1278639..01bf014 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,33 +1,30 @@
-use anyhow::bail;
-use image::{GenericImageView, ImageReader};
+use image::{GenericImageView, ImageReader, Rgba};
-const TOAST_TIME_SECONDS: u64 = 30;
+const TOAST_TIME_SECONDS: u64 = 10;
const CENTER_X: f64 = 100.0;
const CENTER_Y: f64 = 100.0;
-const BREAD_HEIGHT: f64 = 0.2;
+const BREAD_HEIGHT: f64 = 0.3;
const IDLE_HEIGHT: f64 = BREAD_HEIGHT + 8.0;
-const PIXEL_SIZE_MM: f64 = 3.0;
+const PIXEL_SIZE_MM: f64 = 1.5;
fn main() -> anyhow::Result<()> {
let img = ImageReader::open("/home/stephen/Downloads/scd31-qr.png")?.decode()?;
preamble();
- for x in 0..img.width() {
- for y in 0..img.height() {
- let p = img.get_pixel(x, y);
-
- match p.0 {
- [0, 0, 0, 255] => {
- toast(
- x as f64 - (img.width() as f64 / 2.0),
- y as f64 - (img.height() as f64 / 2.0),
- );
- }
- [255, 255, 255, 255] => {
- // white
- }
- _ => bail!("Pixel was not entirely black nor entirely white: {:?}", p),
+ // 2x oversampling
+ for x in 0..(img.width() * 2 - 1) {
+ for y in 0..(img.height() * 2 - 1) {
+ let black = is_black(img.get_pixel(x / 2, y / 2))
+ && is_black(img.get_pixel(x / 2 + x % 2, y / 2))
+ && is_black(img.get_pixel(x / 2, y / 2 + y % 2))
+ && is_black(img.get_pixel(x / 2 + x % 2, y / 2 + y % 2));
+
+ if black {
+ toast(
+ x as f64 - (img.width() as f64 / 2.0),
+ y as f64 + (img.height() as f64 / 2.0), // correct for reflection when printing
+ );
}
}
}
@@ -35,6 +32,14 @@ fn main() -> anyhow::Result<()> {
Ok(())
}
+fn is_black(p: Rgba<u8>) -> bool {
+ match p.0 {
+ [0, 0, 0, 255] => true,
+ [255, 255, 255, 255] => false,
+ _ => panic!("Pixel was not entirely black nor entirely white: {:?}", p),
+ }
+}
+
fn preamble() {
println!(
r#"
--
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