[nasadem] make image a feautre

Cargo.toml

@@ -16,6 +16,7 @@ clap       = { version = "4.4.2", features = ["derive"] }
 criterion  = { version = "0.5", features = ["html_reports"] }
 dashmap    = "5.5.3"
 geo        = "0.26.0"
+image      = "0"
 log        = "0.4.20"
 memmap2    = "0.7.1"
 num-traits = "0.2.16"

nasadem/Cargo.toml

@@ -10,8 +10,13 @@ readme      = "README.md"
 repository  = "https://github.com/jaykickliter/geoprof"
 version     = "0.1.0"
 
+[features]
+default = []
+image = ["dep:image"]
+
 [dependencies]
 byteorder = { workspace = true }
 geo       = { workspace = true }
 memmap2   = { workspace = true }
 thiserror = { workspace = true }
+image     = { workspace = true, optional = true }

nasadem/src/lib.rs

@@ -17,6 +17,8 @@ use geo::{
     geometry::{Coord, Polygon},
     polygon,
 };
+#[cfg(feature = "image")]
+use image::{ImageBuffer, Luma};
 use memmap2::Mmap;
 use std::{
     fs::File,
@@ -307,6 +309,29 @@ impl Tile {
             (x: w, y: s),
         ]
     }
+
+    /// Returns an [image] of this tile.
+    ///
+    /// [image]: image::ImageBuffer
+    #[cfg(feature = "image")]
+    // https://docs.rs/image/latest/image/struct.ImageBuffer.html
+    pub fn to_image(&self) -> ImageBuffer<Luma<u16>, Vec<u16>> {
+        let (x_dim, y_dim) = self.dimensions();
+        let mut img = ImageBuffer::new(x_dim as u32, y_dim as u32);
+        let min_elev = self.min_elevation() as f32;
+        let max_elev = self.max_elevation() as f32;
+        let scale = |m: i16| {
+            let m = m as f32;
+            (m - min_elev) / (max_elev - min_elev) * u16::MAX as f32
+        };
+        for sample in self.iter() {
+            let (x, y) = sample.index();
+            let elev = sample.elevation();
+            let scaled_elev = scale(elev);
+            img.put_pixel(x as u32, (y_dim - 1 - y) as u32, Luma([scaled_elev as u16]))
+        }
+        img
+    }
 }
 
 /// Private API

nasadem/zorderize/Cargo.toml

@@ -6,5 +6,5 @@ edition = "2021"
 [dependencies]
 clap    = { workspace = true }
 glob    = "0"
-image   = "0"
-nasadem = { path = ".." }
+image   = { workspace = true }
+nasadem = { path = "..", features = ["image"] }

nasadem/zorderize/src/main.rs

@@ -14,24 +14,6 @@ struct Cmd {
     dest: Option<PathBuf>,
 }
 
-fn tile_to_img(tile: &Tile) -> ImageBuffer<Luma<u16>, Vec<u16>> {
-    let (x_dim, y_dim) = tile.dimensions();
-    let mut img = ImageBuffer::new(x_dim as u32, y_dim as u32);
-    let min_elev = tile.min_elevation() as f32;
-    let max_elev = tile.max_elevation() as f32;
-    let scale = |m: i16| {
-        let m = m as f32;
-        (m - min_elev) / (max_elev - min_elev) * u16::MAX as f32
-    };
-    for sample in tile.iter() {
-        let (x, y) = sample.index();
-        let elev = sample.elevation();
-        let scaled_elev = scale(elev);
-        img.put_pixel(x as u32, (y_dim - 1 - y) as u32, Luma([scaled_elev as u16]))
-    }
-    img
-}
-
 fn scale_to_pow2(img: &ImageBuffer<Luma<u16>, Vec<u16>>) -> ImageBuffer<Luma<u16>, Vec<u16>> {
     let (scaled_x, scaled_y) = match img.dimensions() {
         (1201, 1201) => (1024, 1024),
@@ -44,7 +26,7 @@ fn scale_to_pow2(img: &ImageBuffer<Luma<u16>, Vec<u16>>) -> ImageBuffer<Luma<u16
 fn main() {
     let cli = Cmd::parse();
     let tile = Tile::load(&cli.tile).unwrap();
-    let img = tile_to_img(&tile);
+    let img = tile.to_image();
     let scaled = scale_to_pow2(&img);
     let out = cli.dest.unwrap_or_else(|| {
         let mut out = cli.tile.clone();