splitting picture into individual unicode parts

src/image_wrapper.rs

@@ -1,10 +1,6 @@
-use std::{
+use std::path::Path;
-    fs::OpenOptions,
-    io::{BufWriter, Write},
-    path::Path,
-};
 
-use image::{DynamicImage, GenericImage, ImageReader};
+use image::{DynamicImage, ImageReader};
 
 #[derive(Debug, Clone)]
 pub struct BWImage {

src/main.rs

@@ -3,7 +3,6 @@ use std::path::Path;
 
 mod image_wrapper;
 use image_wrapper::BWImage;
-use sff::FileDescOut;
 mod sff;
 
 /// Iterates over a directory which shall contain images named by their number in the font.
@@ -39,7 +38,7 @@ fn load_font_dir<P: AsRef<Path>>(dir_with_images: P) -> HashMap<u32, BWImage> {
     map
 }
 
-fn image_table_split<P, Q>(
+fn image_split_table<P, Q>(
     src_image: P,
     dst_dir: Q,
     start_number: usize,
@@ -73,6 +72,35 @@ fn image_table_split<P, Q>(
     }
 }
 
+/// Image should contain all characters in a line.
+fn image_split_individual<P, Q>(
+    src_image: P,
+    dst_dir: Q,
+    numbers: &[usize],
+    width_per_elem: usize,
+    height_per_elem: usize,
+) where
+    P: AsRef<Path>,
+    Q: AsRef<Path>,
+{
+    let src_img = image::ImageReader::open(src_image)
+        .unwrap()
+        .decode()
+        .unwrap();
+    assert!(src_img.width() as usize == numbers.len() * width_per_elem);
+    assert!(src_img.height() as usize == height_per_elem);
+    for (col, number_count) in numbers.iter().copied().enumerate() {
+        let img = src_img.crop_imm(
+            (col * width_per_elem) as u32,
+            0,
+            width_per_elem as u32,
+            height_per_elem as u32,
+        );
+        let file_name = format!("{}.png", number_count);
+        img.save(dst_dir.as_ref().join(file_name)).unwrap();
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 struct TableRange {
     start: u32,
@@ -99,7 +127,14 @@ fn sorted_numbers_into_ranges(sorted_numbers: &[u32]) -> Vec<TableRange> {
 }
 
 fn main() {
-    image_table_split("res/test.png", "font", 32, 6, 16, 8, 18);
+    image_split_table("res/ascii.png", "font", 32, 6, 16, 8, 18);
+    image_split_individual(
+        "res/german.png",
+        "font",
+        &[0x00e4, 0x00c4, 0x00f6, 0x00d6, 0x00fc, 0x00dc, 0x00df][..],
+        8,
+        18,
+    );
     let map = load_font_dir("font");
     let mut sorted_keys: Vec<u32> = map.keys().copied().collect();
     sorted_keys.sort();