Get FLUX non-masked image-to-image working - still rough.

invokeai/app/invocations/flux_text_to_image.py

@@ -1,3 +1,5 @@
+from typing import Optional
+
 import torch
 from einops import rearrange
 from PIL import Image
@@ -8,6 +10,7 @@ from invokeai.app.invocations.fields import (
     FluxConditioningField,
     Input,
     InputField,
+    LatentsField,
     WithBoard,
     WithMetadata,
 )
@@ -21,6 +24,8 @@ from invokeai.backend.flux.sampling import denoise, get_noise, get_schedule, pre
 from invokeai.backend.stable_diffusion.diffusion.conditioning_data import FLUXConditioningInfo
 from invokeai.backend.util.devices import TorchDevice
 
+EPS = 1e-6
+
 
 @invocation(
     "flux_text_to_image",
@@ -33,6 +38,18 @@ from invokeai.backend.util.devices import TorchDevice
 class FluxTextToImageInvocation(BaseInvocation, WithMetadata, WithBoard):
     """Text-to-image generation using a FLUX model."""
 
+    # If latents is provided, this means we are doing image-to-image.
+    latents: Optional[LatentsField] = InputField(
+        default=None,
+        description=FieldDescriptions.latents,
+        input=Input.Connection,
+    )
+    denoising_start: float = InputField(
+        default=0.0,
+        ge=0,
+        le=1,
+        description=FieldDescriptions.denoising_start,
+    )
     transformer: TransformerField = InputField(
         description=FieldDescriptions.flux_model,
         input=Input.Connection,
@@ -78,7 +95,10 @@ class FluxTextToImageInvocation(BaseInvocation, WithMetadata, WithBoard):
         t5_embeddings = flux_conditioning.t5_embeds
         clip_embeddings = flux_conditioning.clip_embeds
 
-        transformer_info = context.models.load(self.transformer.transformer)
+        # Load the input latents, if provided.
+        init_latents = context.tensors.load(self.latents.latents_name) if self.latents else None
+        if init_latents is not None:
+            init_latents = init_latents.to(device=TorchDevice.choose_torch_device(), dtype=inference_dtype)
 
         # Prepare input noise.
         x = get_noise(
@@ -90,8 +110,7 @@ class FluxTextToImageInvocation(BaseInvocation, WithMetadata, WithBoard):
             seed=self.seed,
         )
 
-        x, img_ids = prepare_latent_img_patches(x)
-
+        transformer_info = context.models.load(self.transformer.transformer)
         is_schnell = "schnell" in transformer_info.config.config_path
 
         timesteps = get_schedule(
@@ -100,6 +119,22 @@ class FluxTextToImageInvocation(BaseInvocation, WithMetadata, WithBoard):
             shift=not is_schnell,
         )
 
+        # Prepare inputs for image-to-image case.
+        if self.denoising_start > EPS:
+            if init_latents is None:
+                raise ValueError("latents must be provided if denoising_start > 0.")
+
+            # Clip the timesteps schedule based on denoising_start.
+            # TODO(ryand): Should we apply denoising_start in timestep-space rather than timestep-index-space?
+            start_idx = int(self.denoising_start * len(timesteps))
+            timesteps = timesteps[start_idx:]
+
+            # Noise the orig_latents by the appropriate amount for the first timestep.
+            t_0 = timesteps[0]
+            x = t_0 * x + (1.0 - t_0) * init_latents
+
+        x, img_ids = prepare_latent_img_patches(x)
+
         bs, t5_seq_len, _ = t5_embeddings.shape
         txt_ids = torch.zeros(bs, t5_seq_len, 3, dtype=inference_dtype, device=TorchDevice.choose_torch_device())
 

invokeai/app/invocations/image_to_latents.py

@@ -28,6 +28,7 @@ from invokeai.backend.model_manager import LoadedModel
 from invokeai.backend.model_manager.config import BaseModelType
 from invokeai.backend.stable_diffusion.diffusers_pipeline import image_resized_to_grid_as_tensor
 from invokeai.backend.stable_diffusion.vae_tiling import patch_vae_tiling_params
+from invokeai.backend.util.devices import TorchDevice
 
 
 @invocation(
@@ -59,9 +60,12 @@ class ImageToLatentsInvocation(BaseInvocation):
         # TODO(ryand): Write a util function for generating random tensors that is consistent across devices / dtypes.
         # There's a starting point in get_noise(...), but it needs to be extracted and generalized. This function
         # should be used for VAE encode sampling.
-        generator = torch.Generator().manual_seed(0)
+        generator = torch.Generator(device=TorchDevice.choose_torch_device()).manual_seed(0)
         with vae_info as vae:
             assert isinstance(vae, AutoEncoder)
+            image_tensor = image_tensor.to(
+                device=TorchDevice.choose_torch_device(), dtype=TorchDevice.choose_torch_dtype()
+            )
             latents = vae.encode(image_tensor, sample=True, generator=generator)
             return latents
 

invokeai/backend/flux/sampling.py

@@ -91,7 +91,7 @@ def get_schedule(
 
     # shifting the schedule to favor high timesteps for higher signal images
     if shift:
-        # eastimate mu based on linear estimation between two points
+        # estimate mu based on linear estimation between two points
         mu = get_lin_function(y1=base_shift, y2=max_shift)(image_seq_len)
         timesteps = time_shift(mu, 1.0, timesteps)