Depth Anything v2 (#2279)

* define structs

* construct ResidualConvUnit

* forward() for ResidualConvUnit

* implement FeatureFusionBlock

* implement Scratch

* implement DPTHead

* add identity module

* implement forward for DTPHead

* add get_intermediate_layers to DinoVisionTransformer

* implement DepthAnythingV2

* some minor tweaks

* fix compile errors

* fix var builder prefixes

* setup initial example

* use fixed patch size of 37 (518 / 14)

* debugged until output

* print min and max values

* add some dynamism to the output location

* scale input image

* extract prep function

* extract output path function

* normalize image with magic mean and std

* add spectral coloring

* squeeze in the right place

* make enterpolation optional

* use bail instead of panic

* omit unnecessary Shape call

* remove empty curly braces

* use bail instead of assert

* use vb and pp

* remove closures

* extract config object

* Apply rustfmt.

* Fix some clippy lints.

* More lints.

* Use the array methods.

---------

Co-authored-by: laurent <laurent.mazare@gmail.com>

candle-examples/examples/depth_anything_v2/README.md

@@ -0,0 +1,13 @@
+# candle-dinov2
+
+[Depth Anything V2] is a model for Monocular Depth Estimation (MDE, i.e. just using a single image) which
+builds on the [DINOv2](https://github.com/facebookresearch/dinov2) vision transformer.
+
+This example first instantiates the DINOv2 model and then proceeds to create DepthAnythingV2 and run it.
+
+## Running an example with color map and CUDA
+
+```bash
+cargo run --features cuda,depth_anything_v2 --package candle-examples --example depth_anything_v2 -- --color-map --image candle-examples/examples/yolo-v8/assets/bike.jpg 
+```
+

candle-examples/examples/depth_anything_v2/color_map.rs

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+use enterpolation::linear::ConstEquidistantLinear;
+use enterpolation::Generator;
+use palette::LinSrgb;
+
+use candle::Tensor;
+
+pub struct SpectralRColormap {
+    gradient: ConstEquidistantLinear<f32, LinSrgb, 9>,
+}
+
+impl SpectralRColormap {
+    pub(crate) fn new() -> Self {
+        // Define a colormap similar to 'Spectral_r' by specifying key colors.
+        // got the colors from ChatGPT-4o
+        let gradient = ConstEquidistantLinear::<f32, _, 9>::equidistant_unchecked([
+            LinSrgb::new(0.3686, 0.3098, 0.6353), // Dark blue
+            LinSrgb::new(0.1961, 0.5333, 0.7412), // Blue
+            LinSrgb::new(0.4000, 0.7608, 0.6471), // Cyan
+            LinSrgb::new(0.6706, 0.8667, 0.6431), // Green
+            LinSrgb::new(0.9020, 0.9608, 0.5961), // Yellow
+            LinSrgb::new(0.9961, 0.8784, 0.5451), // Orange
+            LinSrgb::new(0.9922, 0.6824, 0.3804), // Red
+            LinSrgb::new(0.9569, 0.4275, 0.2627), // Dark red
+            LinSrgb::new(0.8353, 0.2431, 0.3098), // Dark purple
+        ]);
+        Self { gradient }
+    }
+
+    fn get_color(&self, value: f32) -> LinSrgb {
+        self.gradient.gen(value)
+    }
+
+    pub fn gray2color(&self, gray: &Tensor) -> candle::Result<Tensor> {
+        println!("Gray: {:?}", gray.dims());
+        let gray_values: Vec<f32> = gray.flatten_all()?.to_vec1()?;
+        let rgb_values: Vec<f32> = gray_values
+            .iter()
+            .map(|g| self.get_color(*g))
+            .flat_map(|rgb| [rgb.red, rgb.green, rgb.blue])
+            .collect();
+
+        let [.., height, width] = gray.dims() else {
+            candle::bail!("Not enough dims!")
+        };
+
+        let color = Tensor::from_vec(rgb_values, (*height, *width, 3), gray.device())?;
+
+        color.permute((2, 0, 1))
+    }
+}

candle-examples/examples/depth_anything_v2/main.rs

@@ -0,0 +1,187 @@
+//! Depth Anything V2
+//! https://huggingface.co/spaces/depth-anything/Depth-Anything-V2
+
+#[cfg(feature = "accelerate")]
+extern crate accelerate_src;
+#[cfg(feature = "mkl")]
+extern crate intel_mkl_src;
+
+use std::ffi::OsString;
+use std::path::PathBuf;
+
+use clap::Parser;
+
+use candle::DType::{F32, U8};
+use candle::{DType, Device, Module, Result, Tensor};
+use candle_examples::{load_image, load_image_and_resize, save_image};
+use candle_nn::VarBuilder;
+use candle_transformers::models::depth_anything_v2::{DepthAnythingV2, DepthAnythingV2Config};
+use candle_transformers::models::dinov2;
+
+use crate::color_map::SpectralRColormap;
+
+mod color_map;
+
+// taken these from: https://huggingface.co/spaces/depth-anything/Depth-Anything-V2/blob/main/depth_anything_v2/dpt.py#L207
+const MAGIC_MEAN: [f32; 3] = [0.485, 0.456, 0.406];
+const MAGIC_STD: [f32; 3] = [0.229, 0.224, 0.225];
+
+const DINO_IMG_SIZE: usize = 518;
+
+#[derive(Parser)]
+struct Args {
+    #[arg(long)]
+    dinov2_model: Option<PathBuf>,
+
+    #[arg(long)]
+    depth_anything_v2_model: Option<PathBuf>,
+
+    #[arg(long)]
+    image: PathBuf,
+
+    #[arg(long)]
+    output_dir: Option<PathBuf>,
+
+    #[arg(long)]
+    cpu: bool,
+
+    #[arg(long)]
+    color_map: bool,
+}
+
+pub fn main() -> anyhow::Result<()> {
+    let args = Args::parse();
+    let device = candle_examples::device(args.cpu)?;
+
+    let dinov2_model_file = match args.dinov2_model {
+        None => {
+            let api = hf_hub::api::sync::Api::new()?;
+            let api = api.model("lmz/candle-dino-v2".into());
+            api.get("dinov2_vits14.safetensors")?
+        }
+        Some(dinov2_model) => dinov2_model,
+    };
+    println!("Using file {:?}", dinov2_model_file);
+
+    let vb = unsafe { VarBuilder::from_mmaped_safetensors(&[dinov2_model_file], F32, &device)? };
+    let dinov2 = dinov2::vit_small(vb)?;
+    println!("DinoV2 model built");
+
+    let depth_anything_model_file = match args.depth_anything_v2_model {
+        None => {
+            let api = hf_hub::api::sync::Api::new()?;
+            let api = api.model("jeroenvlek/depth-anything-v2-safetensors".into());
+            api.get("depth_anything_v2_vits.safetensors")?
+        }
+        Some(depth_anything_model) => depth_anything_model,
+    };
+    println!("Using file {:?}", depth_anything_model_file);
+
+    let vb = unsafe {
+        VarBuilder::from_mmaped_safetensors(&[depth_anything_model_file], DType::F32, &device)?
+    };
+
+    let config = DepthAnythingV2Config::vit_small();
+    let depth_anything = DepthAnythingV2::new(&dinov2, &config, vb)?;
+
+    let (original_height, original_width, image) = load_and_prep_image(&args.image, &device)?;
+
+    println!("Loaded image {image:?}");
+
+    let depth = depth_anything.forward(&image)?;
+
+    println!("Got predictions {:?}", depth.shape());
+
+    let output_image = post_process_image(&depth, original_height, original_width, args.color_map)?;
+
+    let output_path = full_output_path(&args.image, &args.output_dir);
+    println!("Saving image to {}", output_path.to_string_lossy());
+    save_image(&output_image, output_path)?;
+
+    Ok(())
+}
+
+fn full_output_path(image_path: &PathBuf, output_dir: &Option<PathBuf>) -> PathBuf {
+    let input_file_name = image_path.file_name().unwrap();
+    let mut output_file_name = OsString::from("depth_");
+    output_file_name.push(input_file_name);
+    let mut output_path = match output_dir {
+        None => image_path.parent().unwrap().to_path_buf(),
+        Some(output_path) => output_path.clone(),
+    };
+    output_path.push(output_file_name);
+
+    output_path
+}
+
+fn load_and_prep_image(
+    image_path: &PathBuf,
+    device: &Device,
+) -> anyhow::Result<(usize, usize, Tensor)> {
+    let (_original_image, original_height, original_width) = load_image(&image_path, None)?;
+
+    let image = load_image_and_resize(&image_path, DINO_IMG_SIZE, DINO_IMG_SIZE)?
+        .unsqueeze(0)?
+        .to_dtype(F32)?
+        .to_device(&device)?;
+
+    let max_pixel_val = Tensor::try_from(255.0f32)?
+        .to_device(&device)?
+        .broadcast_as(image.shape())?;
+    let image = (image / max_pixel_val)?;
+    let image = normalize_image(&image, &MAGIC_MEAN, &MAGIC_STD)?;
+
+    Ok((original_height, original_width, image))
+}
+
+fn normalize_image(image: &Tensor, mean: &[f32; 3], std: &[f32; 3]) -> Result<Tensor> {
+    let mean_tensor =
+        Tensor::from_vec(mean.to_vec(), (3, 1, 1), &image.device())?.broadcast_as(image.shape())?;
+    let std_tensor =
+        Tensor::from_vec(std.to_vec(), (3, 1, 1), &image.device())?.broadcast_as(image.shape())?;
+    image.sub(&mean_tensor)?.div(&std_tensor)
+}
+
+fn post_process_image(
+    image: &Tensor,
+    original_height: usize,
+    original_width: usize,
+    color_map: bool,
+) -> Result<Tensor> {
+    let out = image.interpolate2d(original_height, original_width)?;
+    let out = scale_image(&out)?;
+
+    let out = if color_map {
+        let spectral_r = SpectralRColormap::new();
+        spectral_r.gray2color(&out)?
+    } else {
+        let rgb_slice = [&out, &out, &out];
+        Tensor::cat(&rgb_slice, 0)?.squeeze(1)?
+    };
+
+    let max_pixel_val = Tensor::try_from(255.0f32)?
+        .to_device(out.device())?
+        .broadcast_as(out.shape())?;
+    let out = (out * max_pixel_val)?;
+
+    out.to_dtype(U8)
+}
+
+fn scale_image(depth: &Tensor) -> Result<Tensor> {
+    let flat_values: Vec<f32> = depth.flatten_all()?.to_vec1()?;
+
+    let min_val = flat_values.iter().min_by(|a, b| a.total_cmp(b)).unwrap();
+    let max_val = flat_values.iter().max_by(|a, b| a.total_cmp(b)).unwrap();
+
+    let min_val_tensor = Tensor::try_from(*min_val)?
+        .to_device(depth.device())?
+        .broadcast_as(depth.shape())?;
+    let depth = (depth - min_val_tensor)?;
+
+    let range = max_val - min_val;
+    let range_tensor = Tensor::try_from(range)?
+        .to_device(depth.device())?
+        .broadcast_as(depth.shape())?;
+
+    depth / range_tensor
+}