Add image tracing to SVG support using vtrace, python skia. The Skia library can be used for additional drawing tasks

comfy/cmd/folder_paths.py

@@ -1,83 +1,17 @@
 from __future__ import annotations
 
-import dataclasses
 import logging
 import os
 import sys
 import time
-from typing import Optional, List, Set, Dict, Any, Iterator, Sequence
+from typing import Optional, List
 
 from ..cli_args import args
 from ..component_model.files import get_package_as_path
+from ..component_model.folder_path_types import FolderPathsTuple, FolderNames, SaveImagePathResponse
+from ..component_model.folder_path_types import supported_pt_extensions as _supported_pt_extensions
 
-supported_pt_extensions = frozenset(['.ckpt', '.pt', '.bin', '.pth', '.safetensors', '.pkl', '.sft'])
+supported_pt_extensions = _supported_pt_extensions
-
-
-@dataclasses.dataclass
-class FolderPathsTuple:
-    folder_name: str
-    paths: List[str] = dataclasses.field(default_factory=list)
-    supported_extensions: Set[str] = dataclasses.field(default_factory=lambda: set(supported_pt_extensions))
-
-    def __getitem__(self, item: Any):
-        if item == 0:
-            return self.paths
-        if item == 1:
-            return self.supported_extensions
-        else:
-            raise RuntimeError("unsupported tuple index")
-
-    def __add__(self, other: "FolderPathsTuple"):
-        assert self.folder_name == other.folder_name
-        # todo: make sure the paths are actually unique, as this method intends
-        new_paths = list(frozenset(self.paths + other.paths))
-        new_supported_extensions = self.supported_extensions | other.supported_extensions
-        return FolderPathsTuple(self.folder_name, new_paths, new_supported_extensions)
-
-    def __iter__(self) -> Iterator[Sequence[str]]:
-        yield self.paths
-        yield self.supported_extensions
-
-
-class FolderNames:
-    def __init__(self, default_new_folder_path: str):
-        self.contents: Dict[str, FolderPathsTuple] = dict()
-        self.default_new_folder_path = default_new_folder_path
-
-    def __getitem__(self, item) -> FolderPathsTuple:
-        if not isinstance(item, str):
-            raise RuntimeError("expected folder path")
-        if item not in self.contents:
-            default_path = os.path.join(self.default_new_folder_path, item)
-            os.makedirs(default_path, exist_ok=True)
-            self.contents[item] = FolderPathsTuple(item, paths=[default_path], supported_extensions=set())
-        return self.contents[item]
-
-    def __setitem__(self, key: str, value: FolderPathsTuple):
-        assert isinstance(key, str)
-        if isinstance(value, tuple):
-            paths, supported_extensions = value
-            value = FolderPathsTuple(key, paths, supported_extensions)
-        self.contents[key] = value
-
-    def __len__(self):
-        return len(self.contents)
-
-    def __iter__(self):
-        return iter(self.contents)
-
-    def __delitem__(self, key):
-        del self.contents[key]
-
-    def items(self):
-        return self.contents.items()
-
-    def values(self):
-        return self.contents.values()
-
-    def keys(self):
-        return self.contents.keys()
-
 
 # todo: this should be initialized elsewhere
 if 'main.py' in sys.argv:
@@ -385,7 +319,7 @@ def get_save_image_path(filename_prefix, output_dir, image_width=0, image_height
     except FileNotFoundError:
         os.makedirs(full_output_folder, exist_ok=True)
         counter = 1
-    return full_output_folder, filename, counter, subfolder, filename_prefix
+    return SaveImagePathResponse(full_output_folder, filename, counter, subfolder, filename_prefix)
 
 
 def create_directories():

comfy/component_model/folder_path_types.py

@@ -0,0 +1,81 @@
+from __future__ import annotations
+
+import dataclasses
+import os
+from typing import List, Set, Any, Iterator, Sequence, Dict, NamedTuple
+
+supported_pt_extensions = frozenset(['.ckpt', '.pt', '.bin', '.pth', '.safetensors', '.pkl', '.sft'])
+
+
+@dataclasses.dataclass
+class FolderPathsTuple:
+    folder_name: str
+    paths: List[str] = dataclasses.field(default_factory=list)
+    supported_extensions: Set[str] = dataclasses.field(default_factory=lambda: set(supported_pt_extensions))
+
+    def __getitem__(self, item: Any):
+        if item == 0:
+            return self.paths
+        if item == 1:
+            return self.supported_extensions
+        else:
+            raise RuntimeError("unsupported tuple index")
+
+    def __add__(self, other: "FolderPathsTuple"):
+        assert self.folder_name == other.folder_name
+        # todo: make sure the paths are actually unique, as this method intends
+        new_paths = list(frozenset(self.paths + other.paths))
+        new_supported_extensions = self.supported_extensions | other.supported_extensions
+        return FolderPathsTuple(self.folder_name, new_paths, new_supported_extensions)
+
+    def __iter__(self) -> Iterator[Sequence[str]]:
+        yield self.paths
+        yield self.supported_extensions
+
+
+class FolderNames:
+    def __init__(self, default_new_folder_path: str):
+        self.contents: Dict[str, FolderPathsTuple] = dict()
+        self.default_new_folder_path = default_new_folder_path
+
+    def __getitem__(self, item) -> FolderPathsTuple:
+        if not isinstance(item, str):
+            raise RuntimeError("expected folder path")
+        if item not in self.contents:
+            default_path = os.path.join(self.default_new_folder_path, item)
+            os.makedirs(default_path, exist_ok=True)
+            self.contents[item] = FolderPathsTuple(item, paths=[default_path], supported_extensions=set())
+        return self.contents[item]
+
+    def __setitem__(self, key: str, value: FolderPathsTuple):
+        assert isinstance(key, str)
+        if isinstance(value, tuple):
+            paths, supported_extensions = value
+            value = FolderPathsTuple(key, paths, supported_extensions)
+        self.contents[key] = value
+
+    def __len__(self):
+        return len(self.contents)
+
+    def __iter__(self):
+        return iter(self.contents)
+
+    def __delitem__(self, key):
+        del self.contents[key]
+
+    def items(self):
+        return self.contents.items()
+
+    def values(self):
+        return self.contents.values()
+
+    def keys(self):
+        return self.contents.keys()
+
+
+class SaveImagePathResponse(NamedTuple):
+    full_output_folder: str
+    filename: str
+    counter: int
+    subfolder: str
+    filename_prefix: str

comfy_extras/nodes/nodes_compositing.py

@@ -1,11 +1,18 @@
+from enum import Enum
+
 import numpy as np
 import torch
+from skimage import exposure
+
 import comfy.utils
-from enum import Enum
+from comfy.component_model.tensor_types import RGBImageBatch, ImageBatch
+from comfy.nodes.package_typing import CustomNode
+
 
 def resize_mask(mask, shape):
     return torch.nn.functional.interpolate(mask.reshape((-1, 1, mask.shape[-2], mask.shape[-1])), size=(shape[0], shape[1]), mode="bilinear").squeeze(1)
 
+
 class PorterDuffMode(Enum):
     ADD = 0
     CLEAR = 1
@@ -69,7 +76,7 @@ def porter_duff_composite(src_image: torch.Tensor, src_alpha: torch.Tensor, dst_
     elif mode == PorterDuffMode.OVERLAY:
         out_alpha = src_alpha + dst_alpha - src_alpha * dst_alpha
         out_image = torch.where(2 * dst_image < dst_alpha, 2 * src_image * dst_image,
-            src_alpha * dst_alpha - 2 * (dst_alpha - src_image) * (src_alpha - dst_image))
+                                src_alpha * dst_alpha - 2 * (dst_alpha - src_image) * (src_alpha - dst_image))
     elif mode == PorterDuffMode.SCREEN:
         out_alpha = src_alpha + dst_alpha - src_alpha * dst_alpha
         out_image = src_image + dst_image - src_image * dst_image
@@ -128,7 +135,7 @@ class PorterDuffImageComposite:
             src_image = source[i]
             dst_image = destination[i]
 
-            assert src_image.shape[2] == dst_image.shape[2] # inputs need to have same number of channels
+            assert src_image.shape[2] == dst_image.shape[2]  # inputs need to have same number of channels
 
             src_alpha = source_alpha[i].unsqueeze(2)
             dst_alpha = destination_alpha[i].unsqueeze(2)
@@ -159,9 +166,9 @@ class SplitImageWithAlpha:
     @classmethod
     def INPUT_TYPES(s):
         return {
-                "required": {
+            "required": {
-                    "image": ("IMAGE",),
+                "image": ("IMAGE",),
-                }
+            }
         }
 
     CATEGORY = "mask/compositing"
@@ -169,8 +176,8 @@ class SplitImageWithAlpha:
     FUNCTION = "split_image_with_alpha"
 
     def split_image_with_alpha(self, image: torch.Tensor):
-        out_images = [i[:,:,:3] for i in image]
+        out_images = [i[:, :, :3] for i in image]
-        out_alphas = [i[:,:,3] if i.shape[2] > 3 else torch.ones_like(i[:,:,0]) for i in image]
+        out_alphas = [i[:, :, 3] if i.shape[2] > 3 else torch.ones_like(i[:, :, 0]) for i in image]
         result = (torch.stack(out_images), 1.0 - torch.stack(out_alphas))
         return result
 
@@ -179,10 +186,10 @@ class JoinImageWithAlpha:
     @classmethod
     def INPUT_TYPES(s):
         return {
-                "required": {
+            "required": {
-                    "image": ("IMAGE",),
+                "image": ("IMAGE",),
-                    "alpha": ("MASK",),
+                "alpha": ("MASK",),
-                }
+            }
         }
 
     CATEGORY = "mask/compositing"
@@ -195,19 +202,124 @@ class JoinImageWithAlpha:
 
         alpha = 1.0 - resize_mask(alpha, image.shape[1:])
         for i in range(batch_size):
-           out_images.append(torch.cat((image[i][:,:,:3], alpha[i].unsqueeze(2)), dim=2))
+            out_images.append(torch.cat((image[i][:, :, :3], alpha[i].unsqueeze(2)), dim=2))
 
         result = (torch.stack(out_images),)
         return result
 
 
+class Flatten(CustomNode):
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "images": ("IMAGE",),
+                "background_color": ("STRING", {"default": "#FFFFFF"})
+            }
+        }
+
+    RETURN_TYPES = ("IMAGE",)
+    FUNCTION = "convert_rgba_to_rgb"
+
+    CATEGORY = "image/postprocessing"
+
+    def convert_rgba_to_rgb(self, images: ImageBatch, background_color) -> tuple[RGBImageBatch]:
+        bg_color = torch.tensor(self.hex_to_rgb(background_color), dtype=torch.float32) / 255.0
+        rgb = images[..., :3]
+        alpha = images[..., 3:4]
+        bg = bg_color.view(1, 1, 1, 3).expand(rgb.shape)
+        blended = alpha * rgb + (1 - alpha) * bg
+
+        return (blended,)
+
+    @staticmethod
+    def hex_to_rgb(hex_color):
+        hex_color = hex_color.lstrip('#')
+        return tuple(int(hex_color[i:i + 2], 16) for i in (0, 2, 4))
+
+
+class EnhanceContrast(CustomNode):
+    @classmethod
+    def INPUT_TYPES(s):
+        return {
+            "required": {
+                "image": ("IMAGE",),
+                "method": (["Histogram Equalization", "Adaptive Equalization", "Contrast Stretching"],),
+                "clip_limit": ("FLOAT", {"default": 0.03, "min": 0.0, "max": 1.0, "step": 0.01}),
+                "lower_percentile": ("FLOAT", {"default": 2.0, "min": 0.0, "max": 100.0, "step": 0.1}),
+                "upper_percentile": ("FLOAT", {"default": 98.0, "min": 0.0, "max": 100.0, "step": 0.1}),
+            },
+        }
+
+    RETURN_TYPES = ("IMAGE",)
+    FUNCTION = "enhance_contrast"
+
+    CATEGORY = "image/adjustments"
+
+    def enhance_contrast(self, image: torch.Tensor, method: str, clip_limit: float, lower_percentile: float, upper_percentile: float) -> tuple[RGBImageBatch]:
+        assert image.dim() == 4 and image.shape[-1] == 3, "Input must be a batch of RGB images"
+
+        image = image.cpu()
+
+        processed_images = []
+        for img in image:
+            img_np = img.numpy()
+
+            if method == "Histogram Equalization":
+                enhanced = exposure.equalize_hist(img_np)
+            elif method == "Adaptive Equalization":
+                enhanced = exposure.equalize_adapthist(img_np, clip_limit=clip_limit)
+            elif method == "Contrast Stretching":
+                p_low, p_high = np.percentile(img_np, (lower_percentile, upper_percentile))
+                enhanced = exposure.rescale_intensity(img_np, in_range=(p_low, p_high))
+            else:
+                raise ValueError(f"Unknown method: {method}")
+
+            processed_images.append(torch.from_numpy(enhanced.astype(np.float32)))
+
+        result = torch.stack(processed_images)
+
+        return (result,)
+
+
+class Posterize(CustomNode):
+    @classmethod
+    def INPUT_TYPES(s):
+        return {
+            "required": {
+                "image": ("IMAGE",),
+                "levels": ("INT", {
+                    "default": 4,
+                    "min": 2,
+                    "max": 256,
+                    "step": 1
+                }),
+            },
+        }
+
+    RETURN_TYPES = ("IMAGE",)
+    FUNCTION = "posterize"
+
+    CATEGORY = "image/adjustments"
+
+    def posterize(self, image: RGBImageBatch, levels: int) -> tuple[RGBImageBatch]:
+        assert image.dim() == 4 and image.shape[-1] == 3, "Input must be a batch of RGB images"
+        image = image.cpu()
+        scale = (levels - 1) / 255.0
+        quantized = torch.round(image * 255.0 * scale) / scale / 255.0
+        posterized = torch.clamp(quantized, 0, 1)
+        return (posterized,)
+
+
 NODE_CLASS_MAPPINGS = {
     "PorterDuffImageComposite": PorterDuffImageComposite,
     "SplitImageWithAlpha": SplitImageWithAlpha,
     "JoinImageWithAlpha": JoinImageWithAlpha,
+    "EnhanceContrast": EnhanceContrast,
+    "Posterize": Posterize,
+    "Flatten": Flatten
 }
 
-
 NODE_DISPLAY_NAME_MAPPINGS = {
     "PorterDuffImageComposite": "Porter-Duff Image Composite",
     "SplitImageWithAlpha": "Split Image with Alpha",

comfy_extras/nodes/nodes_language.py

@@ -21,6 +21,8 @@ from transformers.models.nllb.tokenization_nllb import \
 from typing_extensions import TypedDict
 
 from comfy import model_management
+from comfy.cmd import folder_paths
+from comfy.component_model.folder_path_types import SaveImagePathResponse
 from comfy.language.chat_templates import KNOWN_CHAT_TEMPLATES
 from comfy.language.language_types import ProcessorResult
 from comfy.language.transformers_model_management import TransformersManagedModel
@@ -609,6 +611,38 @@ class PreviewString(CustomNode):
         return {"ui": {"string": [value]}}
 
 
+class SaveString(CustomNode):
+    @classmethod
+    def INPUT_TYPES(cls) -> InputTypes:
+        return {
+            "required": {
+                "value": ("STRING", {"forceInput": True}),
+                "filename_prefix": ("STRING", {"default": "ComfyUI", "tooltip": "The prefix for the file to save. This may include formatting information such as %date:yyyy-MM-dd% or %Empty Latent Image.width% to include values from nodes."})
+            },
+            "optional": {
+                "extension": ("STRING", {"default": ".json"})
+            }
+        }
+
+    CATEGORY = "language"
+    FUNCTION = "execute"
+    OUTPUT_NODE = True
+
+    def get_save_path(self, filename_prefix) -> SaveImagePathResponse:
+        return folder_paths.get_save_image_path(filename_prefix, folder_paths.get_output_directory(), 0, 0)
+
+    def execute(self, value: str | list[str], filename_prefix: str, extension: str = ".json"):
+        full_output_folder, filename, counter, subfolder, filename_prefix = self.get_save_path(filename_prefix)
+        if isinstance(value, str):
+            value = [value]
+
+        for i, value_i in enumerate(value):
+            # roughly matches the behavior of save image, but does not support batch numbers
+            with open(os.path.join(full_output_folder, f"{filename}_{counter:05d}_{extension}" if len(value) == 1 else f"{filename}_{counter:05d}_{i:02d}_{extension}"), "wt+") as f:
+                f.write(value_i)
+        return {"ui": {"string": value}}
+
+
 NODE_CLASS_MAPPINGS = {}
 for cls in (
         TransformerTopKSampler,
@@ -627,5 +661,6 @@ for cls in (
         TransformersFlores200LanguageCodes,
         TransformersTranslationTokenize,
         PreviewString,
+        SaveString,
 ):
     NODE_CLASS_MAPPINGS[cls.__name__] = cls

comfy_extras/nodes/nodes_open_api.py

@@ -649,8 +649,6 @@ class SaveImagesResponse(CustomNode):
         if "ui" in ui_images_result and "images" in ui_images_result["ui"]:
             ui_images_result["result"] = (ui_images_result["ui"]["images"],)
 
-        print(ui_images_result)
-
         return ui_images_result
 
     def subfolder_of(self, local_uri, output_directory):

comfy_extras/nodes/nodes_svg.py

@@ -0,0 +1,165 @@
+import logging
+
+import numpy as np
+import skia
+import torch
+import vtracer
+from PIL import Image
+
+from comfy.nodes.package_typing import CustomNode
+
+
+def RGB2RGBA(image: Image, mask: Image) -> Image:
+    (R, G, B) = image.convert('RGB').split()
+    return Image.merge('RGBA', (R, G, B, mask.convert('L')))
+
+
+def pil2tensor(image: Image) -> torch.Tensor:
+    return torch.from_numpy(np.array(image).astype(np.float32) / 255.0).unsqueeze(0)
+
+
+def tensor2pil(t_image: torch.Tensor) -> Image:
+    return Image.fromarray(np.clip(255.0 * t_image.cpu().numpy().squeeze(), 0, 255).astype(np.uint8))
+
+
+class ImageToSVG(CustomNode):
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "image": ("IMAGE",),
+                "colormode": (["color", "binary"], {"default": "color"}),
+                "hierarchical": (["stacked", "cutout"], {"default": "stacked"}),
+                "mode": (["spline", "polygon", "none"], {"default": "spline"}),
+                "filter_speckle": ("INT", {"default": 4, "min": 0, "max": 100}),
+                "color_precision": ("INT", {"default": 6, "min": 0, "max": 10}),
+                "layer_difference": ("INT", {"default": 16, "min": 0, "max": 256}),
+                "corner_threshold": ("INT", {"default": 60, "min": 0, "max": 180}),
+                "length_threshold": ("FLOAT", {"default": 4.0, "min": 0.0, "max": 10.0}),
+                "max_iterations": ("INT", {"default": 10, "min": 1, "max": 70}),
+                "splice_threshold": ("INT", {"default": 45, "min": 0, "max": 180}),
+                "path_precision": ("INT", {"default": 3, "min": 0, "max": 10}),
+            }
+        }
+
+    RETURN_TYPES = ("STRING",)
+    RETURN_NAMES = ("SVG",)
+    FUNCTION = "convert_to_svg"
+
+    CATEGORY = "image/svg"
+
+    def convert_to_svg(self, image, colormode, hierarchical, mode, filter_speckle, color_precision, layer_difference, corner_threshold, length_threshold, max_iterations, splice_threshold, path_precision):
+        svg_strings = []
+
+        for i in image:
+            i = torch.unsqueeze(i, 0)
+            _image = tensor2pil(i)
+
+            if _image.mode != 'RGBA':
+                alpha = Image.new('L', _image.size, 255)
+                _image.putalpha(alpha)
+
+            pixels = list(_image.getdata())
+
+            size = _image.size
+
+            svg_str = vtracer.convert_pixels_to_svg(
+                pixels,
+                size=size,
+                colormode=colormode,
+                hierarchical=hierarchical,
+                mode=mode,
+                filter_speckle=filter_speckle,
+                color_precision=color_precision,
+                layer_difference=layer_difference,
+                corner_threshold=corner_threshold,
+                length_threshold=length_threshold,
+                max_iterations=max_iterations,
+                splice_threshold=splice_threshold,
+                path_precision=path_precision
+            )
+
+            svg_strings.append(svg_str)
+
+        return (svg_strings,)
+
+
+class SVGToImage(CustomNode):
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "svg": ("STRING", {"forceInput": True}),
+                "scale": ("FLOAT", {"default": 1.0, "min": 0.1, "max": 10.0, "step": 0.1}),
+            }
+        }
+
+    RETURN_TYPES = ("IMAGE",)
+    FUNCTION = "convert_to_image"
+
+    CATEGORY = "image/svg"
+
+    def clean_svg_string(self, svg_string):
+        svg_start = svg_string.find("<svg")
+        if svg_start == -1:
+            raise ValueError("No <svg> tag found in the input string")
+        return svg_string[svg_start:]
+
+    def convert_to_image(self, svg, scale):
+        raster_images = []
+
+        for i, svg_string in enumerate(svg):
+            stream = None
+            try:
+                cleaned_svg = self.clean_svg_string(svg_string)
+
+                stream = skia.MemoryStream(cleaned_svg.encode('utf-8'), True)
+                svg_dom = skia.SVGDOM.MakeFromStream(stream)
+
+                if svg_dom is None:
+                    raise ValueError(f"Failed to parse SVG content for image {i}")
+
+                svg_width = svg_dom.containerSize().width()
+                svg_height = svg_dom.containerSize().height()
+
+                width = int(svg_width * scale)
+                height = int(svg_height * scale)
+
+                surface = skia.Surface(width, height)
+                with surface as canvas:
+                    canvas.clear(skia.ColorTRANSPARENT)
+
+                    canvas.scale(scale, scale)
+                    svg_dom.render(canvas)
+
+                image = surface.makeImageSnapshot()
+                img_array = np.array(image.toarray())
+
+                # BGR to RGB
+                img_array = img_array[..., :3][:, :, ::-1]
+                img_tensor = torch.from_numpy(img_array.astype(np.float32) / 255.0)
+
+                raster_images.append(img_tensor)
+            except Exception as exc_info:
+                logging.error("Error when trying to encode SVG, returning error rectangle instead", exc_info=exc_info)
+                # Create a small red image to indicate error
+                error_img = np.full((64, 64, 4), [255, 0, 0, 255], dtype=np.uint8)
+                error_tensor = torch.from_numpy(error_img.astype(np.float32) / 255.0)
+                raster_images.append(error_tensor)
+            finally:
+                if stream is not None:
+                    del stream
+
+        if not raster_images:
+            raise ValueError("No valid images were generated from the input SVGs")
+
+        # Stack all images into a single batch
+        batch = torch.stack(raster_images)
+
+        return (batch,)
+
+
+NODE_CLASS_MAPPINGS = {
+    "ImageToSVG": ImageToSVG,
+    "SVGToImage": SVGToImage,
+}

requirements.txt

@@ -63,3 +63,5 @@ jaxtyping
 spandrel_extra_arches
 ml_dtypes
 diffusers>=0.30.1
+vtracer
+CairoSVG

tests/downloader/test_huggingface_downloads.py

@@ -51,7 +51,7 @@ async def test_known_repos(tmp_path_factory):
     os.environ["HF_HUB_CACHE"] = str(tmp_path_factory.mktemp("huggingface_root_cache"))
 
     from comfy.cmd import folder_paths
-    from comfy.cmd.folder_paths import FolderPathsTuple
+    from comfy.component_model.folder_path_types import FolderPathsTuple
     from comfy.model_downloader import get_huggingface_repo_list, \
         get_or_download_huggingface_repo, _get_cache_hits, _delete_repo_from_huggingface_cache
     from comfy.model_downloader import KNOWN_HUGGINGFACE_MODEL_REPOS

tests/unit/test_compositing_nodes.py

@@ -0,0 +1,42 @@
+import torch
+
+from comfy_extras.nodes.nodes_compositing import Posterize, EnhanceContrast
+
+
+def test_posterize():
+    posterize_node = Posterize()
+
+    # Create a sample image
+    sample_image = torch.rand((1, 64, 64, 3))
+
+    # Test with different levels
+    for levels in [2, 4, 8, 16]:
+        result = posterize_node.posterize(sample_image, levels)
+        assert isinstance(result[0], torch.Tensor)
+        assert result[0].shape == sample_image.shape
+
+        # Check if the unique values are within the expected range
+        unique_values = torch.unique(result[0])
+        assert len(unique_values) <= levels
+
+
+def test_enhance_contrast():
+    enhance_contrast_node = EnhanceContrast()
+
+    # Create a sample image
+    sample_image = torch.rand((1, 64, 64, 3))
+
+    # Test Histogram Equalization
+    result = enhance_contrast_node.enhance_contrast(sample_image, "Histogram Equalization", 0.03, 2.0, 98.0)
+    assert isinstance(result[0], torch.Tensor)
+    assert result[0].shape == sample_image.shape
+
+    # Test Adaptive Equalization
+    result = enhance_contrast_node.enhance_contrast(sample_image, "Adaptive Equalization", 0.05, 2.0, 98.0)
+    assert isinstance(result[0], torch.Tensor)
+    assert result[0].shape == sample_image.shape
+
+    # Test Contrast Stretching
+    result = enhance_contrast_node.enhance_contrast(sample_image, "Contrast Stretching", 0.03, 1.0, 99.0)
+    assert isinstance(result[0], torch.Tensor)
+    assert result[0].shape == sample_image.shape

tests/unit/test_language_nodes.py

@@ -0,0 +1,59 @@
+import os
+import tempfile
+from unittest.mock import patch
+
+import pytest
+
+from comfy_extras.nodes.nodes_language import SaveString
+
+
+@pytest.fixture
+def save_string_node():
+    return SaveString()
+
+
+@pytest.fixture
+def mock_get_save_path(save_string_node):
+    with patch.object(save_string_node, 'get_save_path') as mock_method:
+        mock_method.return_value = (tempfile.gettempdir(), "test", 0, "", "test")
+        yield mock_method
+
+
+def test_save_string_single(save_string_node, mock_get_save_path):
+    test_string = "Test string content"
+    result = save_string_node.execute(test_string, "test_prefix", ".txt")
+
+    assert result == {"ui": {"string": [test_string]}}
+    mock_get_save_path.assert_called_once_with("test_prefix")
+
+    saved_file_path = os.path.join(tempfile.gettempdir(), "test_00000_.txt")
+    assert os.path.exists(saved_file_path)
+    with open(saved_file_path, "r") as f:
+        assert f.read() == test_string
+
+
+def test_save_string_list(save_string_node, mock_get_save_path):
+    test_strings = ["First string", "Second string", "Third string"]
+    result = save_string_node.execute(test_strings, "test_prefix", ".txt")
+
+    assert result == {"ui": {"string": test_strings}}
+    mock_get_save_path.assert_called_once_with("test_prefix")
+
+    for i, test_string in enumerate(test_strings):
+        saved_file_path = os.path.join(tempfile.gettempdir(), f"test_00000_{i:02d}_.txt")
+        assert os.path.exists(saved_file_path)
+        with open(saved_file_path, "r") as f:
+            assert f.read() == test_string
+
+
+def test_save_string_default_extension(save_string_node, mock_get_save_path):
+    test_string = "Test string content"
+    result = save_string_node.execute(test_string, "test_prefix")
+
+    assert result == {"ui": {"string": [test_string]}}
+    mock_get_save_path.assert_called_once_with("test_prefix")
+
+    saved_file_path = os.path.join(tempfile.gettempdir(), "test_00000_.json")
+    assert os.path.exists(saved_file_path)
+    with open(saved_file_path, "r") as f:
+        assert f.read() == test_string

tests/unit/test_svg.py

@@ -0,0 +1,38 @@
+import pytest
+import torch
+
+from comfy_extras.nodes.nodes_svg import ImageToSVG, SVGToImage
+
+
+@pytest.fixture
+def sample_image():
+    return torch.rand((1, 64, 64, 3))
+
+
+def test_image_to_svg(sample_image):
+    image_to_svg_node = ImageToSVG()
+
+    svg_result, = image_to_svg_node.convert_to_svg(sample_image, "color", "stacked", "spline", 4, 6, 16, 60, 4.0, 10, 45, 3)
+    assert isinstance(svg_result[0], str)
+    assert svg_result[0].startswith('<?xml')
+
+    svg_result, = image_to_svg_node.convert_to_svg(sample_image, "binary", "cutout", "polygon", 2, 8, 32, 90, 2.0, 5, 30, 5)
+    assert isinstance(svg_result[0], str)
+    assert svg_result[0].startswith('<?xml')
+
+
+def test_svg_to_image():
+    svg_to_image_node = SVGToImage()
+
+    test_svg = '''<?xml version="1.0" encoding="UTF-8"?>
+    <svg xmlns="http://www.w3.org/2000/svg" width="100" height="100">
+        <rect width="100" height="100" fill="red" />
+    </svg>'''
+
+    image_result, = svg_to_image_node.convert_to_image([test_svg], 1.0)
+    assert isinstance(image_result, torch.Tensor)
+    assert image_result.shape == (1, 100, 100, 3)
+
+    image_result, = svg_to_image_node.convert_to_image([test_svg], 2.0)
+    assert isinstance(image_result, torch.Tensor)
+    assert image_result.shape == (1, 200, 200, 3)