Merge pull request 'better dithering, keep aspect ratio, send image' (#2) from next into main

Reviewed-on: #2

.github/workflows/rust.yml

@@ -26,7 +26,7 @@ jobs:
       - name: Install rust toolchain
         run: sudo apt-get install -qy cargo-1.80 rust-1.80-clippy
       - name: Install system dependencies
-        run: sudo apt-get install -qy liblzma-dev
+        run: sudo apt-get install -qy liblzma-dev libpipewire-0.3-dev libclang-dev libdbus-1-dev
 
       - name: Run Clippy
         run: cargo clippy --all-targets --all-features

Cargo.toml

@@ -1,9 +1,9 @@
 [package]
 name = "servicepoint-cli"
 description = "A command line interface for the ServicePoint display."
-version = "0.1.0"
+version = "0.3.0"
 edition = "2021"
-rust-version = "1.78.0"
+rust-version = "1.80.0"
 publish = true
 resolver = "2"
 readme = "README.md"
@@ -13,7 +13,10 @@ homepage = "https://crates.io/crates/servicepoint-cli"
 keywords = ["cccb", "cccb-servicepoint", "cli"]
 
 [dependencies]
-servicepoint = { version = "0.13.0", features = ["protocol_websocket"] }
-clap = { version = "4.5", features = ["derive"]}
+servicepoint = { version = "0.13.2", features = ["protocol_websocket"] }
+clap = { version = "4.5", features = ["derive"] }
 env_logger = "0.11"
 log = "0.4"
+scap = "0.0.8"
+image = "0.25.5"
+fast_image_resize = { version = "5.1.2", features = ["image"] }

README.md

@@ -31,13 +31,120 @@ cd servicepoint-cli
 cargo run -- <args>
 ```
 
+## Usage
+
+```
+Usage: servicepoint-cli [OPTIONS] <COMMAND>
+
+Commands:
+  reset-everything  Reset both pixels and brightness [aliases: r]
+  pixels            Commands for manipulating pixels [aliases: p]
+  brightness        Commands for manipulating the brightness [aliases: b]
+  text              Commands for sending text to the screen [aliases: t]
+  help              Print this message or the help of the given subcommand(s)
+
+Options:
+  -d, --destination <DESTINATION>  ip:port of the servicepoint display [default: 127.0.0.1:2342]
+  -t, --transport <TRANSPORT>      protocol to use for communication with display [default: udp] [possible values: udp, web-socket, fake]
+  -v, --verbose                    verbose logging
+  -h, --help                       Print help
+  -V, --version                    Print version
+```
+
+### Pixels
+
+```
+Commands for manipulating pixels
+
+Usage: servicepoint-cli pixels <COMMAND>
+
+Commands:
+  off     Reset all pixels to the default (off) state [aliases: r, reset, clear]
+  flip    Invert the state of all pixels [aliases: f]
+  on      Set all pixels to the on state
+  image   Send an image file (e.g. jpeg or png) to the display. [aliases: i]
+  screen  Stream the default screen capture source to the display. On Linux Wayland, this pops up a screen or window chooser, but it also may directly start streaming your main screen. [aliases: s]
+```
+
+#### Image
+
+```
+Send an image file (e.g. jpeg or png) to the display.
+
+Usage: servicepoint-cli pixels image [OPTIONS] <FILE_NAME>
+
+Arguments:
+  <FILE_NAME>  
+
+Options:
+      --no-hist     Disable histogram correction
+      --no-blur     Disable blur
+      --no-sharp    Disable sharpening
+      --no-dither   Disable dithering. Brightness will be adjusted so that around half of the pixels are on.
+      --no-spacers  Do not remove the spacers from the image.
+      --no-aspect   Do not keep aspect ratio when resizing.
+```
+
+#### Screen
+
+```
+Stream the default screen capture source to the display. On Linux Wayland, this pops up a screen or window chooser, but it also may directly start streaming your main screen.
+
+Usage: servicepoint-cli pixels screen [OPTIONS]
+
+Options:
+  -p, --pointer     Show mouse pointer in video feed
+      --no-hist     Disable histogram correction
+      --no-blur     Disable blur
+      --no-sharp    Disable sharpening
+      --no-dither   Disable dithering. Brightness will be adjusted so that around half of the pixels are on.
+      --no-spacers  Do not remove the spacers from the image.
+      --no-aspect   Do not keep aspect ratio when resizing.
+```
+
+### Brightness
+
+```
+Commands for manipulating the brightness
+
+Usage: servicepoint-cli brightness <COMMAND>
+
+Commands:
+  max   Reset brightness to the default (max) level [aliases: r, reset]
+  set   Set one brightness for the whole screen [aliases: s]
+  min   Set brightness to lowest possible level.
+```
+
+### Text
+
+```
+Commands for sending text to the screen
+
+Usage: servicepoint-cli text <COMMAND>
+
+Commands:
+  stdin  Pipe text to the display, example: `journalctl | servicepoint-cli stream stdin`
+```
+
+#### Stdin
+
+```
+Pipe text to the display, example: `journalctl | servicepoint-cli stream stdin`
+
+Usage: servicepoint-cli stream stdin [OPTIONS]
+
+Options:
+  -s, --slow  Wait for a short amount of time before sending the next line
+```
+
+
 ## Contributing
 
 If you have ideas on how to improve the code, add features or improve documentation feel free to open a pull request.
 
 You think you found a bug? Please open an issue.
 
-Submissions on Forgejo are preferred, but you can also use GitHub. 
+Submissions on [Forgejo](https://git.berlin.ccc.de/servicepoint/servicepoint-cli) are preferred, but you can also use [GitHub](https://github.com/kaesaecracker/servicepoint-cli). 
 
 All creatures welcome.
 

flake.lock

@@ -7,11 +7,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1736429655,
-        "narHash": "sha256-BwMekRuVlSB9C0QgwKMICiJ5EVbLGjfe4qyueyNQyGI=",
+        "lastModified": 1739824009,
+        "narHash": "sha256-fcNrCMUWVLMG3gKC5M9CBqVOAnJtyRvGPxptQFl5mVg=",
         "owner": "nix-community",
         "repo": "naersk",
-        "rev": "0621e47bd95542b8e1ce2ee2d65d6a1f887a13ce",
+        "rev": "e5130d37369bfa600144c2424270c96f0ef0e11d",
         "type": "github"
       },
       "original": {
@@ -37,11 +37,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1736549401,
-        "narHash": "sha256-ibkQrMHxF/7TqAYcQE+tOnIsSEzXmMegzyBWza6uHKM=",
+        "lastModified": 1740603184,
+        "narHash": "sha256-t+VaahjQAWyA+Ctn2idyo1yxRIYpaDxMgHkgCNiMJa4=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "1dab772dd4a68a7bba5d9460685547ff8e17d899",
+        "rev": "f44bd8ca21e026135061a0a57dcf3d0775b67a49",
         "type": "github"
       },
       "original": {

flake.nix

@@ -1,5 +1,5 @@
 {
-  description = "Flake for servicepoint-cli";
+  description = "Flake for command line interface of the ServicePoint display.";
 
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-24.11";
@@ -55,12 +55,25 @@
             };
             nativeBuildInputs = with pkgs; [
               pkg-config
+              libclang
+              rustPlatform.bindgenHook
             ];
             strictDeps = true;
-            buildInputs = with pkgs; [
-              xe
-              xz
-            ];
+            buildInputs =
+              with pkgs;
+              [
+                xe
+                xz
+                clang
+              ]
+              ++ lib.optionals pkgs.stdenv.isLinux (
+                with pkgs;
+                [
+                  dbus
+                  pipewire
+                  libclang
+                ]
+              );
           };
 
           default = servicepoint-cli;
@@ -90,6 +103,7 @@
                   cargo-expand
                 ];
               })
+              pkgs.cargo-flamegraph
             ];
             LD_LIBRARY_PATH = "${pkgs.lib.makeLibraryPath (builtins.concatMap (d: d.buildInputs) inputsFrom)}";
             RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";

src/brightness.rs

@@ -0,0 +1,20 @@
+use crate::cli::BrightnessCommand;
+use log::info;
+use servicepoint::{Brightness, Command, Connection};
+
+pub(crate) fn brightness(connection: &Connection, brightness_command: BrightnessCommand) {
+    match brightness_command {
+        BrightnessCommand::Max => brightness_set(connection, Brightness::MAX),
+        BrightnessCommand::Min => brightness_set(connection, Brightness::MIN),
+        BrightnessCommand::Set { brightness } => {
+            brightness_set(connection, Brightness::saturating_from(brightness))
+        }
+    }
+}
+
+pub(crate) fn brightness_set(connection: &Connection, brightness: Brightness) {
+    connection
+        .send(Command::Brightness(brightness))
+        .expect("Failed to set brightness");
+    info!("set brightness to {brightness:?}");
+}

src/cli.rs

@@ -1,5 +1,9 @@
 #[derive(clap::Parser, std::fmt::Debug)]
-#[clap(version, arg_required_else_help = true)]
+#[clap(
+    version,
+    arg_required_else_help = true,
+    about = "A command line interface for the ServicePoint display."
+)]
 pub struct Cli {
     #[arg(
         short,
@@ -24,7 +28,7 @@ pub struct Cli {
 
 #[derive(clap::Parser, std::fmt::Debug)]
 pub enum Mode {
-    #[command(visible_alias = "r")]
+    #[command(visible_alias = "r", about = "Reset both pixels and brightness")]
     ResetEverything,
     #[command(visible_alias = "p")]
     Pixels {
@@ -36,24 +40,67 @@ pub enum Mode {
         #[clap(subcommand)]
         brightness_command: BrightnessCommand,
     },
+    #[command(visible_alias = "t")]
+    Text {
+        #[clap(subcommand)]
+        text_command: TextCommand,
+    },
 }
 
 #[derive(clap::Parser, std::fmt::Debug)]
+#[clap(about = "Commands for manipulating pixels")]
 pub enum PixelCommand {
-    #[command(visible_alias = "r")]
-    Reset,
+    #[command(
+        visible_alias = "r",
+        visible_alias = "reset",
+        visible_alias = "clear",
+        about = "Reset all pixels to the default (off) state"
+    )]
+    Off,
+    #[command(visible_alias = "f", about = "Invert the state of all pixels")]
+    Flip,
+    #[command(about = "Set all pixels to the on state")]
+    On,
+    #[command(
+        visible_alias = "i",
+        about = "Send an image file (e.g. jpeg or png) to the display."
+    )]
+    Image {
+        #[command(flatten)]
+        send_image_options: SendImageOptions,
+        #[command(flatten)]
+        image_processing_options: ImageProcessingOptions,
+    },
+    #[command(
+        visible_alias = "s",
+        about = "Stream the default screen capture source to the display. \
+        On Linux Wayland, this pops up a screen or window chooser, \
+        but it also may directly start streaming your main screen."
+    )]
+    Screen {
+        #[command(flatten)]
+        stream_options: StreamScreenOptions,
+        #[command(flatten)]
+        image_processing: ImageProcessingOptions,
+    },
 }
 
 #[derive(clap::Parser, std::fmt::Debug)]
+#[clap(about = "Commands for manipulating the brightness")]
 pub enum BrightnessCommand {
-    #[command(visible_alias = "r")]
-    Reset,
-    #[command(visible_alias = "s")]
+    #[command(
+        visible_alias = "r",
+        visible_alias = "reset",
+        about = "Reset brightness to the default (max) level"
+    )]
+    Max,
+    #[command(visible_alias = "s", about = "Set one brightness for the whole screen")]
     Set {
+        #[arg()]
         brightness: u8,
     },
+    #[command(about = "Set brightness to lowest possible level.")]
     Min,
-    Max,
 }
 
 #[derive(clap::ValueEnum, Clone, Debug)]
@@ -62,3 +109,61 @@ pub enum Protocol {
     WebSocket,
     Fake,
 }
+
+#[derive(clap::Parser, std::fmt::Debug)]
+#[clap(about = "Commands for sending text to the screen")]
+pub enum TextCommand {
+    #[command(
+        about = "Pipe text to the display, example: `journalctl | servicepoint-cli stream stdin`"
+    )]
+    Stdin {
+        #[arg(
+            long,
+            short,
+            default_value_t = false,
+            help = "Wait for a short amount of time before sending the next line"
+        )]
+        slow: bool,
+    },
+}
+
+#[derive(clap::Parser, std::fmt::Debug, Clone)]
+pub struct StreamScreenOptions {
+    #[arg(
+        long,
+        short,
+        default_value_t = false,
+        help = "Show mouse pointer in video feed"
+    )]
+    pub pointer: bool,
+}
+
+#[derive(clap::Parser, std::fmt::Debug, Clone)]
+pub struct ImageProcessingOptions {
+    #[arg(long, help = "Disable histogram correction")]
+    pub no_hist: bool,
+
+    #[arg(long, help = "Disable blur")]
+    pub no_blur: bool,
+
+    #[arg(long, help = "Disable sharpening")]
+    pub no_sharp: bool,
+
+    #[arg(
+        long,
+        help = "Disable dithering. Brightness will be adjusted so that around half of the pixels are on."
+    )]
+    pub no_dither: bool,
+
+    #[arg(long, help = "Do not remove the spacers from the image.")]
+    pub no_spacers: bool,
+
+    #[arg(long, help = "Do not keep aspect ratio when resizing.")]
+    pub no_aspect: bool,
+}
+
+#[derive(clap::Parser, std::fmt::Debug, Clone)]
+pub struct SendImageOptions {
+    #[arg()]
+    pub file_name: String,
+}

src/execute.rs

@@ -1,52 +0,0 @@
-use crate::cli::{BrightnessCommand, Mode, PixelCommand};
-use log::info;
-use servicepoint::{Brightness, Command, Connection};
-
-pub fn execute_mode(mode: Mode, connection: Connection) {
-    match mode {
-        Mode::ResetEverything => {
-            brightness_reset(&connection);
-            pixels_reset(&connection);
-        }
-        Mode::Pixels { pixel_command } => pixels(&connection, pixel_command),
-        Mode::Brightness { brightness_command } => brightness(&connection, brightness_command),
-    }
-}
-
-fn pixels(connection: &Connection, pixel_command: PixelCommand) {
-    match pixel_command {
-        PixelCommand::Reset => pixels_reset(connection),
-    }
-}
-
-fn brightness(connection: &Connection, brightness_command: BrightnessCommand) {
-    match brightness_command {
-        BrightnessCommand::Reset => brightness_reset(connection),
-        BrightnessCommand::Min => brightness_set(connection, Brightness::MIN),
-        BrightnessCommand::Max => brightness_set(connection, Brightness::MAX),
-        BrightnessCommand::Set { brightness } => {
-            brightness_set(connection, Brightness::saturating_from(brightness))
-        }
-    }
-}
-
-fn pixels_reset(connection: &Connection) {
-    connection
-        .send(Command::Clear)
-        .expect("failed to clear pixels");
-    info!("Reset pixels");
-}
-
-fn brightness_reset(connection: &Connection) {
-    connection
-        .send(Command::Brightness(Brightness::MAX))
-        .expect("Failed to reset brightness to maximum");
-    info!("Reset brightness");
-}
-
-fn brightness_set(connection: &Connection, brightness: Brightness) {
-    connection
-        .send(Command::Brightness(brightness))
-        .expect("Failed to set brightness");
-    info!("set brightness to {brightness:?}");
-}

src/image_processing.rs

@@ -0,0 +1,172 @@
+use crate::{
+    cli::ImageProcessingOptions,
+    ledwand_dither::{blur, histogram_correction, median_brightness, ostromoukhov_dither, sharpen},
+};
+use fast_image_resize::{ResizeOptions, Resizer};
+use image::{DynamicImage, GrayImage};
+use log::{debug, trace};
+use servicepoint::{Bitmap, Grid, PIXEL_HEIGHT, PIXEL_WIDTH, TILE_HEIGHT, TILE_SIZE};
+use std::{default::Default, time::Instant};
+
+#[derive(Debug)]
+pub struct ImageProcessingPipeline {
+    options: ImageProcessingOptions,
+    resizer: Resizer,
+    render_size: (u32, u32),
+}
+
+const SPACER_HEIGHT: usize = TILE_SIZE / 2;
+
+impl ImageProcessingPipeline {
+    pub fn new(options: ImageProcessingOptions) -> Self {
+        debug!("Creating image pipeline: {:?}", options);
+
+        let height = PIXEL_HEIGHT
+            + if options.no_spacers {
+                0
+            } else {
+                SPACER_HEIGHT * (TILE_HEIGHT - 1)
+            };
+
+        Self {
+            options,
+            resizer: Resizer::new(),
+            render_size: (PIXEL_WIDTH as u32, height as u32),
+        }
+    }
+
+    pub fn process(&mut self, frame: DynamicImage) -> Bitmap {
+        let start_time = Instant::now();
+
+        let frame = self.resize_grayscale(frame);
+        let frame = self.grayscale_processing(frame);
+        let mut result = self.grayscale_to_bitmap(frame);
+
+        if !self.options.no_spacers {
+            result = Self::remove_spacers(result);
+        }
+
+        trace!("pipeline took {:?}", start_time.elapsed());
+        result
+    }
+
+    fn resize_grayscale(&mut self, frame: DynamicImage) -> GrayImage {
+        let start_time = Instant::now();
+
+        let (scaled_width, scaled_height) = if self.options.no_aspect {
+            self.render_size
+        } else {
+            self.calc_scaled_size_keep_aspect((frame.width(), frame.height()))
+        };
+        let mut dst_image = DynamicImage::new(scaled_width, scaled_height, frame.color());
+
+        self.resizer
+            .resize(&frame, &mut dst_image, &ResizeOptions::default())
+            .expect("image resize failed");
+
+        trace!("resizing took {:?}", start_time.elapsed());
+
+        let start_time = Instant::now();
+        let result = dst_image.into_luma8();
+        trace!("grayscale took {:?}", start_time.elapsed());
+
+        result
+    }
+
+    fn grayscale_processing(&self, mut frame: GrayImage) -> GrayImage {
+        let start_time = Instant::now();
+        if !self.options.no_hist {
+            histogram_correction(&mut frame);
+        }
+
+        let mut orig = frame.clone();
+
+        if !self.options.no_blur {
+            blur(&orig, &mut frame);
+            std::mem::swap(&mut frame, &mut orig);
+        }
+
+        if !self.options.no_sharp {
+            sharpen(&orig, &mut frame);
+            std::mem::swap(&mut frame, &mut orig);
+        }
+
+        trace!("image processing took {:?}", start_time.elapsed());
+        orig
+    }
+
+    fn grayscale_to_bitmap(&self, orig: GrayImage) -> Bitmap {
+        let start_time = Instant::now();
+        let result = if self.options.no_dither {
+            let cutoff = median_brightness(&orig);
+            let bits = orig.iter().map(move |x| x > &cutoff).collect();
+            Bitmap::from_bitvec(orig.width() as usize, bits)
+        } else {
+            ostromoukhov_dither(orig, u8::MAX / 2)
+        };
+        trace!("bitmap conversion took {:?}", start_time.elapsed());
+        result
+    }
+
+    fn remove_spacers(source: Bitmap) -> Bitmap {
+        let start_time = Instant::now();
+
+        let width = source.width();
+        let result_height = Self::calc_height_without_spacers(source.height());
+        let mut result = Bitmap::new(width, result_height);
+
+        let mut source_y = 0;
+        for result_y in 0..result_height {
+            for x in 0..width {
+                result.set(x, result_y, source.get(x, source_y));
+            }
+
+            if result_y != 0 && result_y % TILE_SIZE == 0 {
+                source_y += SPACER_HEIGHT;
+            }
+            source_y += 1;
+        }
+
+        trace!("removing spacers took {:?}", start_time.elapsed());
+        result
+    }
+
+    fn calc_height_without_spacers(height: usize) -> usize {
+        let full_tile_rows_with_spacers = height / (TILE_SIZE + SPACER_HEIGHT);
+        let remaining_pixel_rows = height % (TILE_SIZE + SPACER_HEIGHT);
+        let total_spacer_height = full_tile_rows_with_spacers * SPACER_HEIGHT
+            + remaining_pixel_rows.saturating_sub(TILE_SIZE);
+        let height_without_spacers = height - total_spacer_height;
+        trace!(
+            "spacers take up {total_spacer_height}, resulting in final height {height_without_spacers}"
+        );
+        height_without_spacers
+    }
+
+    fn calc_scaled_size_keep_aspect(&self, source: (u32, u32)) -> (u32, u32) {
+        let (source_width, source_height) = source;
+        let (target_width, target_height) = self.render_size;
+        debug_assert_eq!(target_width % TILE_SIZE as u32, 0);
+
+        let width_scale = target_width as f32 / source_width as f32;
+        let height_scale = target_height as f32 / source_height as f32;
+        let scale = f32::min(width_scale, height_scale);
+
+        let height = (source_height as f32 * scale) as u32;
+        let mut width = (source_width as f32 * scale) as u32;
+
+        if width % TILE_SIZE as u32 != 0 {
+            // because we do not have many pixels, round up even if it is a worse fit
+            width += 8 - width % 8;
+        }
+
+        let result = (width, height);
+        trace!(
+            "scaling {:?} to {:?} to fit {:?}",
+            source,
+            result,
+            self.render_size
+        );
+        result
+    }
+}

src/ledwand_dither.rs

@@ -0,0 +1,507 @@
+//! Based on https://github.com/WarkerAnhaltRanger/CCCB_Ledwand
+
+use image::GrayImage;
+use servicepoint::{BitVec, Bitmap, PIXEL_HEIGHT};
+
+type GrayHistogram = [usize; 256];
+
+struct HistogramCorrection {
+    pre_offset: f32,
+    post_offset: f32,
+    factor: f32,
+}
+
+pub fn histogram_correction(image: &mut GrayImage) {
+    let histogram = make_histogram(image);
+    let correction = determine_histogram_correction(image, histogram);
+    apply_histogram_correction(image, correction)
+}
+
+fn make_histogram(image: &GrayImage) -> GrayHistogram {
+    let mut histogram = [0; 256];
+    for pixel in image.pixels() {
+        histogram[pixel.0[0] as usize] += 1;
+    }
+    histogram
+}
+
+fn determine_histogram_correction(
+    image: &GrayImage,
+    histogram: GrayHistogram,
+) -> HistogramCorrection {
+    let adjustment_pixels = image.len() / PIXEL_HEIGHT;
+
+    let mut num_pixels = 0;
+    let mut brightness = 0;
+
+    let mincut = loop {
+        num_pixels += histogram[brightness as usize];
+        brightness += 1;
+        if num_pixels >= adjustment_pixels {
+            break u8::min(brightness, 20);
+        }
+    };
+
+    let minshift = loop {
+        num_pixels += histogram[brightness as usize];
+        brightness += 1;
+        if num_pixels >= 2 * adjustment_pixels {
+            break u8::min(brightness, 64);
+        }
+    };
+
+    brightness = u8::MAX;
+    num_pixels = 0;
+    let maxshift = loop {
+        num_pixels += histogram[brightness as usize];
+        brightness -= 1;
+        if num_pixels >= 2 * adjustment_pixels {
+            break u8::max(brightness, 192);
+        }
+    };
+
+    let pre_offset = -(mincut as f32 / 2.);
+    let post_offset = -(minshift as f32);
+    let factor = (255.0 - post_offset) / maxshift as f32;
+    HistogramCorrection {
+        pre_offset,
+        post_offset,
+        factor,
+    }
+}
+
+fn apply_histogram_correction(image: &mut GrayImage, correction: HistogramCorrection) {
+    for pixel in image.pixels_mut() {
+        let pixel = &mut pixel.0[0];
+        let value =
+            (*pixel as f32 + correction.pre_offset) * correction.factor + correction.post_offset;
+        *pixel = value.clamp(0f32, u8::MAX as f32) as u8;
+    }
+}
+
+pub fn median_brightness(image: &GrayImage) -> u8 {
+    let histogram = make_histogram(image);
+    let midpoint = image.len() / 2;
+
+    debug_assert_eq!(
+        image.len(),
+        histogram.iter().copied().map(usize::from).sum()
+    );
+
+    let mut num_pixels = 0;
+    for brightness in u8::MIN..=u8::MAX {
+        num_pixels += histogram[brightness as usize];
+        if num_pixels >= midpoint {
+            return brightness;
+        }
+    }
+
+    unreachable!("Somehow less pixels where counted in the histogram than exist in the image")
+}
+
+pub fn blur(source: &GrayImage, destination: &mut GrayImage) {
+    assert_eq!(source.len(), destination.len());
+
+    copy_border(source, destination);
+    blur_inner_pixels(source, destination);
+}
+
+pub fn sharpen(source: &GrayImage, destination: &mut GrayImage) {
+    assert_eq!(source.len(), destination.len());
+
+    copy_border(source, destination);
+    sharpen_inner_pixels(source, destination);
+}
+
+fn copy_border(source: &GrayImage, destination: &mut GrayImage) {
+    let last_row = source.height() - 1;
+    for x in 0..source.width() {
+        destination[(x, 0)] = source[(x, 0)];
+        destination[(x, last_row)] = source[(x, last_row)];
+    }
+    let last_col = source.width() - 1;
+    for y in 0..source.height() {
+        destination[(0, y)] = source[(0, y)];
+        destination[(last_col, y)] = source[(last_col, y)];
+    }
+}
+
+fn blur_inner_pixels(source: &GrayImage, destination: &mut GrayImage) {
+    for y in 1..source.height() - 2 {
+        for x in 1..source.width() - 2 {
+            let weighted_sum = source.get_pixel(x - 1, y - 1).0[0] as u32
+                + source.get_pixel(x, y - 1).0[0] as u32
+                + source.get_pixel(x + 1, y - 1).0[0] as u32
+                + source.get_pixel(x - 1, y).0[0] as u32
+                + 8 * source.get_pixel(x, y).0[0] as u32
+                + source.get_pixel(x + 1, y).0[0] as u32
+                + source.get_pixel(x - 1, y + 1).0[0] as u32
+                + source.get_pixel(x, y + 1).0[0] as u32
+                + source.get_pixel(x + 1, y + 1).0[0] as u32;
+            let blurred = weighted_sum / 16;
+            destination.get_pixel_mut(x, y).0[0] =
+                blurred.clamp(u8::MIN as u32, u8::MAX as u32) as u8;
+        }
+    }
+}
+
+fn sharpen_inner_pixels(source: &GrayImage, destination: &mut GrayImage) {
+    for y in 1..source.height() - 2 {
+        for x in 1..source.width() - 2 {
+            let weighted_sum = -(source.get_pixel(x - 1, y - 1).0[0] as i32)
+                - source.get_pixel(x, y - 1).0[0] as i32
+                - source.get_pixel(x + 1, y - 1).0[0] as i32
+                - source.get_pixel(x - 1, y).0[0] as i32
+                + 9 * source.get_pixel(x, y).0[0] as i32
+                - source.get_pixel(x + 1, y).0[0] as i32
+                - source.get_pixel(x - 1, y + 1).0[0] as i32
+                - source.get_pixel(x, y + 1).0[0] as i32
+                - source.get_pixel(x + 1, y + 1).0[0] as i32;
+            destination.get_pixel_mut(x, y).0[0] =
+                weighted_sum.clamp(u8::MIN as i32, u8::MAX as i32) as u8;
+        }
+    }
+}
+
+pub(crate) fn ostromoukhov_dither(source: GrayImage, bias: u8) -> Bitmap {
+    let width = source.width();
+    let height = source.height();
+    assert_eq!(width % 8, 0);
+
+    let mut source = source.into_raw();
+    let mut destination = BitVec::repeat(false, source.len());
+
+    for y in 0..height as usize {
+        let start = y * width as usize;
+        if y % 2 == 0 {
+            for x in start..start + width as usize {
+                ostromoukhov_dither_pixel(
+                    &mut source,
+                    &mut destination,
+                    x,
+                    width as usize,
+                    y == (height - 1) as usize,
+                    1,
+                    bias,
+                );
+            }
+        } else {
+            for x in (start..start + width as usize).rev() {
+                ostromoukhov_dither_pixel(
+                    &mut source,
+                    &mut destination,
+                    x,
+                    width as usize,
+                    y == (height - 1) as usize,
+                    -1,
+                    bias,
+                );
+            }
+        }
+    }
+
+    Bitmap::from_bitvec(width as usize, destination)
+}
+
+#[inline]
+fn ostromoukhov_dither_pixel(
+    source: &mut [u8],
+    destination: &mut BitVec,
+    position: usize,
+    width: usize,
+    last_row: bool,
+    direction: isize,
+    bias: u8,
+) {
+    let (destination_value, error) = gray_to_bit(source[position], bias);
+    destination.set(position, destination_value);
+
+    let mut diffuse = |to: usize, mat: i16| {
+        let diffuse_value = source[to] as i16 + mat;
+        source[to] = diffuse_value.clamp(u8::MIN.into(), u8::MAX.into()) as u8;
+    };
+
+    let lookup = if destination_value {
+        ERROR_DIFFUSION_MATRIX[error as usize].map(move |i| -i)
+    } else {
+        ERROR_DIFFUSION_MATRIX[error as usize]
+    };
+    diffuse((position as isize + direction) as usize, lookup[0]);
+
+    if !last_row {
+        diffuse(
+            ((position + width) as isize - direction) as usize,
+            lookup[1],
+        );
+        diffuse(((position + width) as isize) as usize, lookup[2]);
+    }
+}
+
+fn gray_to_bit(old_pixel: u8, bias: u8) -> (bool, u8) {
+    let destination_value = old_pixel > bias;
+    let error = if destination_value {
+        255 - old_pixel
+    } else {
+        old_pixel
+    };
+    (destination_value, error)
+}
+
+const ERROR_DIFFUSION_MATRIX: [[i16; 3]; 256] = [
+    [0, 1, 0],
+    [1, 0, 0],
+    [1, 0, 1],
+    [2, 0, 1],
+    [2, 0, 2],
+    [3, 0, 2],
+    [4, 0, 2],
+    [4, 1, 2],
+    [5, 1, 2],
+    [5, 2, 2],
+    [5, 3, 2],
+    [6, 3, 2],
+    [6, 3, 3],
+    [7, 3, 3],
+    [7, 4, 3],
+    [8, 4, 3],
+    [8, 5, 3],
+    [9, 5, 3],
+    [9, 5, 4],
+    [10, 6, 3],
+    [10, 6, 4],
+    [11, 7, 3],
+    [11, 7, 4],
+    [11, 8, 4],
+    [12, 7, 5],
+    [12, 7, 6],
+    [12, 7, 7],
+    [12, 7, 8],
+    [12, 7, 9],
+    [13, 7, 9],
+    [13, 7, 10],
+    [13, 7, 11],
+    [13, 7, 12],
+    [14, 7, 12],
+    [14, 8, 12],
+    [15, 8, 12],
+    [15, 9, 12],
+    [16, 9, 12],
+    [16, 10, 12],
+    [17, 10, 12],
+    [17, 11, 12],
+    [18, 12, 11],
+    [19, 12, 11],
+    [19, 13, 11],
+    [20, 13, 11],
+    [20, 14, 11],
+    [21, 15, 10],
+    [22, 15, 10],
+    [22, 17, 9],
+    [23, 17, 9],
+    [24, 18, 8],
+    [24, 19, 8],
+    [25, 19, 8],
+    [26, 20, 7],
+    [26, 21, 7],
+    [27, 22, 6],
+    [28, 23, 5],
+    [28, 24, 5],
+    [29, 25, 4],
+    [30, 26, 3],
+    [31, 26, 3],
+    [31, 28, 2],
+    [32, 28, 2],
+    [33, 29, 1],
+    [34, 30, 0],
+    [33, 31, 1],
+    [32, 33, 1],
+    [32, 33, 2],
+    [31, 34, 3],
+    [30, 36, 3],
+    [29, 37, 4],
+    [29, 37, 5],
+    [28, 39, 5],
+    [32, 34, 7],
+    [37, 29, 8],
+    [42, 23, 10],
+    [46, 19, 11],
+    [51, 13, 12],
+    [52, 14, 13],
+    [53, 13, 12],
+    [53, 14, 13],
+    [54, 14, 13],
+    [55, 14, 13],
+    [55, 14, 13],
+    [56, 15, 14],
+    [57, 14, 13],
+    [56, 15, 15],
+    [55, 17, 15],
+    [54, 18, 16],
+    [53, 20, 16],
+    [52, 21, 17],
+    [52, 22, 17],
+    [51, 24, 17],
+    [50, 25, 18],
+    [49, 27, 18],
+    [47, 29, 19],
+    [48, 29, 19],
+    [48, 29, 20],
+    [49, 29, 20],
+    [49, 30, 20],
+    [50, 31, 20],
+    [50, 31, 20],
+    [51, 31, 20],
+    [51, 31, 21],
+    [52, 31, 21],
+    [52, 32, 21],
+    [53, 32, 21],
+    [53, 32, 22],
+    [55, 32, 21],
+    [56, 31, 22],
+    [58, 31, 21],
+    [59, 30, 22],
+    [61, 30, 21],
+    [62, 29, 22],
+    [64, 29, 21],
+    [65, 28, 22],
+    [67, 28, 21],
+    [68, 27, 22],
+    [70, 27, 21],
+    [71, 26, 22],
+    [73, 26, 21],
+    [75, 25, 21],
+    [76, 25, 21],
+    [78, 24, 21],
+    [80, 23, 21],
+    [81, 23, 21],
+    [83, 22, 21],
+    [85, 21, 20],
+    [85, 22, 21],
+    [85, 22, 22],
+    [84, 24, 22],
+    [84, 24, 23],
+    [84, 25, 23],
+    [83, 27, 23],
+    [83, 28, 23],
+    [82, 29, 24],
+    [82, 30, 24],
+    [81, 31, 25],
+    [80, 32, 26],
+    [80, 33, 26],
+    [79, 35, 26],
+    [79, 36, 26],
+    [78, 37, 27],
+    [77, 38, 28],
+    [77, 39, 28],
+    [76, 41, 28],
+    [75, 42, 29],
+    [75, 43, 29],
+    [74, 44, 30],
+    [74, 45, 30],
+    [75, 46, 30],
+    [75, 46, 30],
+    [76, 46, 30],
+    [76, 46, 31],
+    [77, 46, 31],
+    [77, 47, 31],
+    [78, 47, 31],
+    [78, 47, 32],
+    [79, 47, 32],
+    [79, 48, 32],
+    [80, 49, 32],
+    [83, 46, 32],
+    [86, 44, 32],
+    [90, 42, 31],
+    [93, 40, 31],
+    [96, 39, 30],
+    [100, 36, 30],
+    [103, 35, 29],
+    [106, 33, 29],
+    [110, 30, 29],
+    [113, 29, 28],
+    [114, 29, 28],
+    [115, 29, 28],
+    [115, 29, 28],
+    [116, 30, 29],
+    [117, 29, 28],
+    [117, 30, 29],
+    [118, 30, 29],
+    [119, 30, 29],
+    [109, 43, 27],
+    [100, 57, 23],
+    [90, 71, 20],
+    [80, 85, 17],
+    [70, 99, 14],
+    [74, 98, 12],
+    [78, 97, 10],
+    [81, 96, 9],
+    [85, 95, 7],
+    [89, 94, 5],
+    [92, 93, 4],
+    [96, 92, 2],
+    [100, 91, 0],
+    [100, 90, 2],
+    [100, 88, 5],
+    [100, 87, 7],
+    [99, 86, 10],
+    [99, 85, 12],
+    [99, 84, 14],
+    [99, 82, 17],
+    [98, 81, 20],
+    [98, 80, 22],
+    [98, 79, 24],
+    [98, 77, 27],
+    [98, 76, 29],
+    [97, 75, 32],
+    [97, 73, 35],
+    [97, 72, 37],
+    [96, 71, 40],
+    [96, 69, 43],
+    [96, 67, 46],
+    [96, 66, 48],
+    [95, 65, 51],
+    [95, 63, 54],
+    [95, 61, 57],
+    [94, 60, 60],
+    [94, 58, 63],
+    [94, 57, 65],
+    [93, 55, 69],
+    [93, 54, 71],
+    [93, 52, 74],
+    [92, 51, 77],
+    [92, 49, 80],
+    [91, 47, 84],
+    [91, 46, 86],
+    [93, 49, 82],
+    [96, 52, 77],
+    [98, 55, 73],
+    [101, 58, 68],
+    [104, 61, 63],
+    [106, 65, 58],
+    [109, 68, 53],
+    [111, 71, 49],
+    [114, 74, 44],
+    [116, 78, 39],
+    [118, 76, 40],
+    [119, 74, 42],
+    [120, 73, 43],
+    [122, 71, 44],
+    [123, 69, 46],
+    [124, 67, 48],
+    [125, 66, 49],
+    [127, 64, 50],
+    [128, 62, 52],
+    [129, 60, 54],
+    [131, 58, 55],
+    [132, 57, 56],
+    [136, 47, 63],
+    [139, 38, 70],
+    [143, 29, 76],
+    [147, 19, 83],
+    [151, 9, 90],
+    [154, 0, 97],
+    [160, 0, 92],
+    [171, 0, 82],
+    [183, 0, 71],
+    [184, 0, 71],
+];

src/main.rs

@@ -1,10 +1,21 @@
-use crate::cli::{Cli, Protocol};
+use crate::{
+    brightness::{brightness, brightness_set},
+    cli::{Cli, Mode, Protocol},
+    pixels::{pixels, pixels_off},
+    text::text
+};
 use clap::Parser;
 use log::debug;
-use servicepoint::Connection;
+use servicepoint::{Brightness, Connection};
 
+mod brightness;
 mod cli;
-mod execute;
+mod image_processing;
+mod ledwand_dither;
+mod pixels;
+mod stream_stdin;
+mod stream_window;
+mod text;
 
 fn main() {
     let cli = Cli::parse();
@@ -14,7 +25,19 @@ fn main() {
     let connection = make_connection(cli.destination, cli.transport);
     debug!("connection established: {:#?}", connection);
 
-    execute::execute_mode(cli.command, connection);
+    execute_mode(cli.command, connection);
+}
+
+pub fn execute_mode(mode: Mode, connection: Connection) {
+    match mode {
+        Mode::ResetEverything => {
+            brightness_set(&connection, Brightness::MAX);
+            pixels_off(&connection);
+        }
+        Mode::Pixels { pixel_command } => pixels(&connection, pixel_command),
+        Mode::Brightness { brightness_command } => brightness(&connection, brightness_command),
+        Mode::Text { text_command} => text(&connection, text_command),
+    }
 }
 
 fn make_connection(destination: String, transport: Protocol) -> Connection {

src/pixels.rs

@@ -0,0 +1,64 @@
+use crate::{
+    image_processing::ImageProcessingPipeline,
+    cli::{ImageProcessingOptions, PixelCommand, SendImageOptions},
+    stream_window::stream_window
+};
+use log::info;
+use servicepoint::{BitVec, Command, CompressionCode, Connection, Origin, PIXEL_COUNT};
+
+pub(crate) fn pixels(connection: &Connection, pixel_command: PixelCommand) {
+    match pixel_command {
+        PixelCommand::Off => pixels_off(connection),
+        PixelCommand::Flip => pixels_invert(connection),
+        PixelCommand::On => pixels_on(connection),
+        PixelCommand::Image {
+            image_processing_options: processing_options,
+            send_image_options: image_options,
+        } => pixels_image(connection, image_options, processing_options),
+        PixelCommand::Screen {
+            stream_options,
+            image_processing,
+        } => stream_window(connection, stream_options, image_processing),
+    }
+}
+
+fn pixels_on(connection: &Connection) {
+    let mask = BitVec::repeat(true, PIXEL_COUNT);
+    connection
+        .send(Command::BitmapLinear(0, mask, CompressionCode::Lzma))
+        .expect("could not send command");
+    info!("turned on all pixels")
+}
+
+fn pixels_invert(connection: &Connection) {
+    let mask = BitVec::repeat(true, PIXEL_COUNT);
+    connection
+        .send(Command::BitmapLinearXor(0, mask, CompressionCode::Lzma))
+        .expect("could not send command");
+    info!("inverted all pixels");
+}
+
+pub(crate) fn pixels_off(connection: &Connection) {
+    connection
+        .send(Command::Clear)
+        .expect("failed to clear pixels");
+    info!("reset pixels");
+}
+
+fn pixels_image(
+    connection: &Connection,
+    options: SendImageOptions,
+    processing_options: ImageProcessingOptions,
+) {
+    let image = image::open(&options.file_name).expect("failed to open image file");
+    let mut pipeline = ImageProcessingPipeline::new(processing_options);
+    let bitmap = pipeline.process(image);
+    connection
+        .send(Command::BitmapLinearWin(
+            Origin::ZERO,
+            bitmap,
+            CompressionCode::default(),
+        ))
+        .expect("failed to send image command");
+    info!("sent image to display");
+}

src/stream_stdin.rs

@@ -0,0 +1,82 @@
+use log::warn;
+use servicepoint::*;
+use std::thread::sleep;
+
+pub(crate) fn stream_stdin(connection: &Connection, slow: bool) {
+    warn!("This mode will break when using multi-byte characters and does not support ANSI escape sequences yet.");
+    let mut app = App {
+        connection,
+        mirror: CharGrid::new(TILE_WIDTH, TILE_HEIGHT),
+        y: 0,
+        slow,
+    };
+    app.run()
+}
+
+struct App<'t> {
+    connection: &'t Connection,
+    mirror: CharGrid,
+    y: usize,
+    slow: bool,
+}
+
+impl App<'_> {
+    fn run(&mut self) {
+        self.connection
+            .send(Command::Clear)
+            .expect("couldn't clear screen");
+        let last_y = self.mirror.height() - 1;
+        for line in std::io::stdin().lines() {
+            let line = line.expect("could not read from stdin");
+
+            if self.y <= last_y {
+                self.single_line(&line);
+                self.y += 1;
+            } else {
+                self.shift_rows();
+                Self::line_onto_grid(&mut self.mirror, last_y, &line);
+                self.send_mirror()
+                // we stay on last y
+            }
+
+            if self.slow {
+                sleep(FRAME_PACING);
+            }
+        }
+    }
+
+    fn shift_rows(&mut self) {
+        let data = self.mirror.data_ref_mut();
+        data.rotate_left(TILE_WIDTH);
+        if let Some(row) = data.last_chunk_mut::<TILE_WIDTH>() {
+            row.fill(' ')
+        }
+    }
+
+    fn line_onto_grid(grid: &mut CharGrid, y: usize, line: &str) {
+        for (x, char) in line.chars().enumerate() {
+            if x < grid.width() {
+                grid.set(x, y, char);
+            }
+        }
+    }
+
+    fn send_mirror(&self) {
+        self.connection
+            .send(Command::Utf8Data(
+                Origin::ZERO,
+                self.mirror.clone(),
+            ))
+            .expect("couldn't send screen to display");
+    }
+
+    fn single_line(&mut self, line: &str) {
+        let mut line_grid = CharGrid::new(TILE_WIDTH, 1);
+        line_grid.fill(' ');
+        Self::line_onto_grid(&mut line_grid, 0, line);
+        Self::line_onto_grid(&mut self.mirror, self.y, line);
+        self.connection
+            .send(Command::Utf8Data(Origin::new(0, self.y), line_grid))
+            .expect("couldn't send single line to screen");
+    }
+}

src/stream_window.rs

@@ -0,0 +1,112 @@
+use crate::{
+    cli::{ImageProcessingOptions, StreamScreenOptions},
+    image_processing::ImageProcessingPipeline,
+};
+use image::{DynamicImage, ImageBuffer, Rgb, Rgba};
+use log::{debug, error, info, trace, warn};
+use scap::{
+    capturer::{Capturer, Options},
+    frame::convert_bgra_to_rgb,
+    frame::Frame,
+};
+use servicepoint::{Command, CompressionCode, Connection, Origin, FRAME_PACING};
+use std::time::{Duration, Instant};
+
+pub fn stream_window(
+    connection: &Connection,
+    options: StreamScreenOptions,
+    processing_options: ImageProcessingOptions,
+) {
+    info!("Starting capture with options: {:?}", options);
+    let capturer = match start_capture(&options) {
+        Some(value) => value,
+        None => return,
+    };
+
+    let mut pipeline = ImageProcessingPipeline::new(processing_options);
+
+    info!("now starting to stream images");
+    loop {
+        let start = Instant::now();
+
+        let frame = capture_frame(&capturer);
+        let frame = frame_to_image(frame);
+        let bitmap = pipeline.process(frame);
+
+        trace!("bitmap ready to send in: {:?}", start.elapsed());
+
+        connection
+            .send(Command::BitmapLinearWin(
+                Origin::ZERO,
+                bitmap.clone(),
+                CompressionCode::default(),
+            ))
+            .expect("failed to send frame to display");
+
+        debug!("frame time: {:?}", start.elapsed());
+    }
+}
+
+fn start_capture(options: &StreamScreenOptions) -> Option<Capturer> {
+    if !scap::is_supported() {
+        error!("platform not supported by scap");
+        return None;
+    }
+
+    if !scap::has_permission() {
+        warn!("requesting screen recording permission");
+        if !scap::request_permission() {
+            error!("screen recording ermission denied");
+            return None;
+        }
+    }
+
+    // all options are more like a suggestion
+    let mut capturer = Capturer::build(Options {
+        fps: FRAME_PACING.div_duration_f32(Duration::from_secs(1)) as u32,
+        show_cursor: options.pointer,
+        output_type: scap::frame::FrameType::BGR0,
+        ..Default::default()
+    })
+    .expect("failed to create screen capture");
+    capturer.start_capture();
+    Some(capturer)
+}
+
+fn capture_frame(capturer: &Capturer) -> Frame {
+    let start_time = Instant::now();
+    let result = capturer.get_next_frame().expect("failed to capture frame");
+    trace!("capture took: {:?}", start_time.elapsed());
+    result
+}
+
+fn frame_to_image(frame: Frame) -> DynamicImage {
+    let start_time = Instant::now();
+    let result = match frame {
+        Frame::BGRx(frame) => bgrx_to_rgb(frame.width, frame.height, frame.data),
+        Frame::RGBx(frame) => DynamicImage::from(
+            ImageBuffer::<Rgba<_>, _>::from_raw(
+                frame.width as u32,
+                frame.height as u32,
+                frame.data,
+            )
+            .unwrap(),
+        ),
+        Frame::BGR0(frame) => bgrx_to_rgb(frame.width, frame.height, frame.data),
+        Frame::RGB(frame) => DynamicImage::from(
+            ImageBuffer::<Rgb<_>, _>::from_raw(frame.width as u32, frame.height as u32, frame.data)
+                .unwrap(),
+        ),
+        Frame::BGRA(frame) => bgrx_to_rgb(frame.width, frame.height, frame.data),
+        Frame::YUVFrame(_) | Frame::XBGR(_) => panic!("unsupported frame format"),
+    };
+    trace!("conversion to image took: {:?}", start_time.elapsed());
+    result
+}
+
+fn bgrx_to_rgb(width: i32, height: i32, data: Vec<u8>) -> DynamicImage {
+    DynamicImage::from(
+        ImageBuffer::<Rgb<_>, _>::from_raw(width as u32, height as u32, convert_bgra_to_rgb(data))
+            .unwrap(),
+    )
+}

src/text.rs

@@ -0,0 +1,7 @@
+use servicepoint::Connection;
+use crate::cli::TextCommand;
+use crate::stream_stdin::stream_stdin;
+
+pub fn text(connection: &Connection, command: TextCommand) {
+   match command { TextCommand::Stdin  { slow } => stream_stdin(connection, slow), }
+}