update

src/diffusers/pipelines/flux/pipeline_flux.py

@@ -197,7 +197,9 @@ def __init__(
         self.vae_scale_factor = (
             2 ** (len(self.vae.config.block_out_channels) - 1) if hasattr(self, "vae") and self.vae is not None else 8
         )
-        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+        # Flux latents are turned into 2x2 patches and packed. This means the latent width and height has to be divisible
+        # by the patch size. So the vae scale factor is multiplied by the patch size to account for this
+        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor * 2)
         self.tokenizer_max_length = (
             self.tokenizer.model_max_length if hasattr(self, "tokenizer") and self.tokenizer is not None else 77
         )
@@ -386,9 +388,9 @@ def check_inputs(
         callback_on_step_end_tensor_inputs=None,
         max_sequence_length=None,
     ):
-        if height % self.vae_scale_factor != 0 or width % self.vae_scale_factor != 0:
-            raise ValueError(
-                f"`height` and `width` have to be divisible by {self.vae_scale_factor} but are {height} and {width}."
+        if height % (self.vae_scale_factor * 2) != 0 or width % (self.vae_scale_factor * 2) != 0:
+            logger.warning(
+                f"`height` and `width` have to be divisible by {self.vae_scale_factor * 2} but are {height} and {width}. Dimensions will be resized accordingly"
             )
 
         if callback_on_step_end_tensor_inputs is not None and not all(

src/diffusers/pipelines/flux/pipeline_flux_controlnet.py

@@ -218,7 +218,9 @@ def __init__(
         self.vae_scale_factor = (
             2 ** (len(self.vae.config.block_out_channels) - 1) if hasattr(self, "vae") and self.vae is not None else 8
         )
-        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+        # Flux latents are turned into 2x2 patches and packed. This means the latent width and height has to be divisible
+        # by the patch size. So the vae scale factor is multiplied by the patch size to account for this
+        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor * 2)
         self.tokenizer_max_length = (
             self.tokenizer.model_max_length if hasattr(self, "tokenizer") and self.tokenizer is not None else 77
         )
@@ -410,9 +412,9 @@ def check_inputs(
         callback_on_step_end_tensor_inputs=None,
         max_sequence_length=None,
     ):
-        if height % self.vae_scale_factor != 0 or width % self.vae_scale_factor != 0:
-            raise ValueError(
-                f"`height` and `width` have to be divisible by {self.vae_scale_factor} but are {height} and {width}."
+        if height % (self.vae_scale_factor * 2) != 0 or width % (self.vae_scale_factor * 2) != 0:
+            logger.warning(
+                f"`height` and `width` have to be divisible by {self.vae_scale_factor * 2} but are {height} and {width}. Dimensions will be resized accordingly"
             )
 
         if callback_on_step_end_tensor_inputs is not None and not all(
@@ -500,8 +502,10 @@ def prepare_latents(
         generator,
         latents=None,
     ):
-        height = int(height) // self.vae_scale_factor
-        width = int(width) // self.vae_scale_factor
+        # VAE applies 8x compression on images but we must also account for packing which requires
+        # latent height and width to be divisible by 2.
+        height = int(height) // self.vae_scale_factor - ((int(height) // self.vae_scale_factor) % 2)
+        width = int(width) // self.vae_scale_factor - ((int(width) // self.vae_scale_factor) % 2)
 
         shape = (batch_size, num_channels_latents, height, width)
 

src/diffusers/pipelines/flux/pipeline_flux_controlnet_image_to_image.py

@@ -230,7 +230,9 @@ def __init__(
         self.vae_scale_factor = (
             2 ** (len(self.vae.config.block_out_channels) - 1) if hasattr(self, "vae") and self.vae is not None else 8
         )
-        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+        # Flux latents are turned into 2x2 patches and packed. This means the latent width and height has to be divisible
+        # by the patch size. So the vae scale factor is multiplied by the patch size to account for this
+        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor * 2)
         self.tokenizer_max_length = (
             self.tokenizer.model_max_length if hasattr(self, "tokenizer") and self.tokenizer is not None else 77
         )
@@ -453,9 +455,9 @@ def check_inputs(
         if strength < 0 or strength > 1:
             raise ValueError(f"The value of strength should in [0.0, 1.0] but is {strength}")
 
-        if height % self.vae_scale_factor != 0 or width % self.vae_scale_factor != 0:
-            raise ValueError(
-                f"`height` and `width` have to be divisible by {self.vae_scale_factor} but are {height} and {width}."
+        if height % self.vae_scale_factor * 2 != 0 or width % self.vae_scale_factor * 2 != 0:
+            logger.warning(
+                f"`height` and `width` have to be divisible by {self.vae_scale_factor * 2} but are {height} and {width}. Dimensions will be resized accordingly"
             )
 
         if callback_on_step_end_tensor_inputs is not None and not all(
@@ -551,8 +553,10 @@ def prepare_latents(
                 f" size of {batch_size}. Make sure the batch size matches the length of the generators."
             )
 
-        height = int(height) // self.vae_scale_factor
-        width = int(width) // self.vae_scale_factor
+        # VAE applies 8x compression on images but we must also account for packing which requires
+        # latent height and width to be divisible by 2.
+        height = int(height) // self.vae_scale_factor - ((int(height) // self.vae_scale_factor) % 2)
+        width = int(width) // self.vae_scale_factor - ((int(width) // self.vae_scale_factor) % 2)
 
         shape = (batch_size, num_channels_latents, height, width)
         latent_image_ids = self._prepare_latent_image_ids(batch_size, height // 2, width // 2, device, dtype)

src/diffusers/pipelines/flux/pipeline_flux_controlnet_inpainting.py

@@ -233,9 +233,11 @@ def __init__(
         self.vae_scale_factor = (
             2 ** (len(self.vae.config.block_out_channels) - 1) if hasattr(self, "vae") and self.vae is not None else 8
         )
-        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+        # Flux latents are turned into 2x2 patches and packed. This means the latent width and height has to be divisible
+        # by the patch size. So the vae scale factor is multiplied by the patch size to account for this
+        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor * 2)
         self.mask_processor = VaeImageProcessor(
-            vae_scale_factor=self.vae_scale_factor,
+            vae_scale_factor=self.vae_scale_factor * 2,
             vae_latent_channels=self.vae.config.latent_channels,
             do_normalize=False,
             do_binarize=True,
@@ -467,9 +469,9 @@ def check_inputs(
         if strength < 0 or strength > 1:
             raise ValueError(f"The value of strength should in [0.0, 1.0] but is {strength}")
 
-        if height % self.vae_scale_factor != 0 or width % self.vae_scale_factor != 0:
-            raise ValueError(
-                f"`height` and `width` have to be divisible by {self.vae_scale_factor} but are {height} and {width}."
+        if height % (self.vae_scale_factor * 2) != 0 or width % (self.vae_scale_factor * 2) != 0:
+            logger.warning(
+                f"`height` and `width` have to be divisible by {self.vae_scale_factor * 2} but are {height} and {width}. Dimensions will be resized accordingly"
             )
 
         if callback_on_step_end_tensor_inputs is not None and not all(
@@ -578,8 +580,10 @@ def prepare_latents(
                 f" size of {batch_size}. Make sure the batch size matches the length of the generators."
             )
 
-        height = int(height) // self.vae_scale_factor
-        width = int(width) // self.vae_scale_factor
+        # VAE applies 8x compression on images but we must also account for packing which requires
+        # latent height and width to be divisible by 2.
+        height = int(height) // self.vae_scale_factor - ((int(height) // self.vae_scale_factor) % 2)
+        width = int(width) // self.vae_scale_factor - ((int(width) // self.vae_scale_factor) % 2)
 
         shape = (batch_size, num_channels_latents, height, width)
         latent_image_ids = self._prepare_latent_image_ids(batch_size, height // 2, width // 2, device, dtype)
@@ -624,8 +628,10 @@ def prepare_mask_latents(
         device,
         generator,
     ):
-        height = int(height) // self.vae_scale_factor
-        width = int(width) // self.vae_scale_factor
+        # VAE applies 8x compression on images but we must also account for packing which requires
+        # latent height and width to be divisible by 2.
+        height = int(height) // self.vae_scale_factor - ((int(height) // self.vae_scale_factor) % 2)
+        width = int(width) // self.vae_scale_factor - ((int(width) // self.vae_scale_factor) % 2)
         # resize the mask to latents shape as we concatenate the mask to the latents
         # we do that before converting to dtype to avoid breaking in case we're using cpu_offload
         # and half precision

src/diffusers/pipelines/flux/pipeline_flux_img2img.py

@@ -214,7 +214,9 @@ def __init__(
         self.vae_scale_factor = (
             2 ** (len(self.vae.config.block_out_channels) - 1) if hasattr(self, "vae") and self.vae is not None else 8
         )
-        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+        # Flux latents are turned into 2x2 patches and packed. This means the latent width and height has to be divisible
+        # by the patch size. So the vae scale factor is multiplied by the patch size to account for this
+        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor * 2)
         self.tokenizer_max_length = (
             self.tokenizer.model_max_length if hasattr(self, "tokenizer") and self.tokenizer is not None else 77
         )
@@ -436,9 +438,9 @@ def check_inputs(
         if strength < 0 or strength > 1:
             raise ValueError(f"The value of strength should in [0.0, 1.0] but is {strength}")
 
-        if height % self.vae_scale_factor != 0 or width % self.vae_scale_factor != 0:
-            raise ValueError(
-                f"`height` and `width` have to be divisible by {self.vae_scale_factor} but are {height} and {width}."
+        if height % (self.vae_scale_factor * 2) != 0 or width % (self.vae_scale_factor * 2) != 0:
+            logger.warning(
+                f"`height` and `width` have to be divisible by {self.vae_scale_factor * 2} but are {height} and {width}. Dimensions will be resized accordingly"
             )
 
         if callback_on_step_end_tensor_inputs is not None and not all(
@@ -533,8 +535,10 @@ def prepare_latents(
                 f" size of {batch_size}. Make sure the batch size matches the length of the generators."
             )
 
-        height = int(height) // self.vae_scale_factor
-        width = int(width) // self.vae_scale_factor
+        # VAE applies 8x compression on images but we must also account for packing which requires
+        # latent height and width to be divisible by 2.
+        height = int(height) // self.vae_scale_factor - ((int(height) // self.vae_scale_factor) % 2)
+        width = int(width) // self.vae_scale_factor - ((int(width) // self.vae_scale_factor) % 2)
 
         shape = (batch_size, num_channels_latents, height, width)
         latent_image_ids = self._prepare_latent_image_ids(batch_size, height // 2, width // 2, device, dtype)

src/diffusers/pipelines/flux/pipeline_flux_inpaint.py

@@ -211,9 +211,11 @@ def __init__(
         self.vae_scale_factor = (
             2 ** (len(self.vae.config.block_out_channels) - 1) if hasattr(self, "vae") and self.vae is not None else 8
         )
-        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+        # Flux latents are turned into 2x2 patches and packed. This means the latent width and height has to be divisible
+        # by the patch size. So the vae scale factor is multiplied by the patch size to account for this
+        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor * 2)
         self.mask_processor = VaeImageProcessor(
-            vae_scale_factor=self.vae_scale_factor,
+            vae_scale_factor=self.vae_scale_factor * 2,
             vae_latent_channels=self.vae.config.latent_channels,
             do_normalize=False,
             do_binarize=True,
@@ -445,9 +447,9 @@ def check_inputs(
         if strength < 0 or strength > 1:
             raise ValueError(f"The value of strength should in [0.0, 1.0] but is {strength}")
 
-        if height % self.vae_scale_factor != 0 or width % self.vae_scale_factor != 0:
-            raise ValueError(
-                f"`height` and `width` have to be divisible by {self.vae_scale_factor} but are {height} and {width}."
+        if height % (self.vae_scale_factor * 2) != 0 or width % (self.vae_scale_factor * 2) != 0:
+            logger.warning(
+                f"`height` and `width` have to be divisible by {self.vae_scale_factor * 2} but are {height} and {width}. Dimensions will be resized accordingly"
             )
 
         if callback_on_step_end_tensor_inputs is not None and not all(
@@ -555,8 +557,10 @@ def prepare_latents(
                 f" size of {batch_size}. Make sure the batch size matches the length of the generators."
             )
 
-        height = int(height) // self.vae_scale_factor
-        width = int(width) // self.vae_scale_factor
+        # VAE applies 8x compression on images but we must also account for packing which requires
+        # latent height and width to be divisible by 2.
+        height = int(height) // self.vae_scale_factor - ((int(height) // self.vae_scale_factor) % 2)
+        width = int(width) // self.vae_scale_factor - ((int(width) // self.vae_scale_factor) % 2)
 
         shape = (batch_size, num_channels_latents, height, width)
         latent_image_ids = self._prepare_latent_image_ids(batch_size, height // 2, width // 2, device, dtype)
@@ -600,8 +604,10 @@ def prepare_mask_latents(
         device,
         generator,
     ):
-        height = int(height) // self.vae_scale_factor
-        width = int(width) // self.vae_scale_factor
+        # VAE applies 8x compression on images but we must also account for packing which requires
+        # latent height and width to be divisible by 2.
+        height = int(height) // self.vae_scale_factor - ((int(height) // self.vae_scale_factor) % 2)
+        width = int(width) // self.vae_scale_factor - ((int(width) // self.vae_scale_factor) % 2)
         # resize the mask to latents shape as we concatenate the mask to the latents
         # we do that before converting to dtype to avoid breaking in case we're using cpu_offload
         # and half precision

tests/pipelines/controlnet_flux/test_controlnet_flux.py

@@ -181,6 +181,20 @@ def test_controlnet_flux(self):
     def test_xformers_attention_forwardGenerator_pass(self):
         pass
 
+    def test_flux_image_output_shape(self):
+        pipe = self.pipeline_class(**self.get_dummy_components()).to(torch_device)
+        inputs = self.get_dummy_inputs(torch_device)
+
+        height_width_pairs = [(32, 32), (72, 56)]
+        for height, width in height_width_pairs:
+            expected_height = height - height % (pipe.vae_scale_factor * 2)
+            expected_width = width - width % (pipe.vae_scale_factor * 2)
+
+            inputs.update({"height": height, "width": width})
+            image = pipe(**inputs).images[0]
+            output_height, output_width = image.shape
+            assert (output_height, output_width) == (expected_height, expected_width)
+
 
 @slow
 @require_big_gpu_with_torch_cuda

tests/pipelines/flux/test_pipeline_flux.py

@@ -191,6 +191,20 @@ def test_fused_qkv_projections(self):
             original_image_slice, image_slice_disabled, atol=1e-2, rtol=1e-2
         ), "Original outputs should match when fused QKV projections are disabled."
 
+    def test_flux_image_output_shape(self):
+        pipe = self.pipeline_class(**self.get_dummy_components()).to(torch_device)
+        inputs = self.get_dummy_inputs(torch_device)
+
+        height_width_pairs = [(32, 32), (72, 56)]
+        for height, width in height_width_pairs:
+            expected_height = height - height % (pipe.vae_scale_factor * 2)
+            expected_width = width - width % (pipe.vae_scale_factor * 2)
+
+            inputs.update({"height": height, "width": width})
+            image = pipe(**inputs).images[0]
+            output_height, output_width, _ = image.shape
+            assert (output_height, output_width) == (expected_height, expected_width)
+
 
 @slow
 @require_big_gpu_with_torch_cuda

tests/pipelines/flux/test_pipeline_flux_img2img.py

@@ -147,3 +147,17 @@ def test_flux_prompt_embeds(self):
 
         max_diff = np.abs(output_with_prompt - output_with_embeds).max()
         assert max_diff < 1e-4
+
+    def test_flux_image_output_shape(self):
+        pipe = self.pipeline_class(**self.get_dummy_components()).to(torch_device)
+        inputs = self.get_dummy_inputs(torch_device)
+
+        height_width_pairs = [(32, 32), (72, 56)]
+        for height, width in height_width_pairs:
+            expected_height = height - height % (pipe.vae_scale_factor * 2)
+            expected_width = width - width % (pipe.vae_scale_factor * 2)
+
+            inputs.update({"height": height, "width": width})
+            image = pipe(**inputs).images[0]
+            output_height, output_width, _ = image.shape
+            assert (output_height, output_width) == (expected_height, expected_width)

tests/pipelines/flux/test_pipeline_flux_inpaint.py

@@ -149,3 +149,17 @@ def test_flux_inpaint_prompt_embeds(self):
 
         max_diff = np.abs(output_with_prompt - output_with_embeds).max()
         assert max_diff < 1e-4
+
+    def test_flux_image_output_shape(self):
+        pipe = self.pipeline_class(**self.get_dummy_components()).to(torch_device)
+        inputs = self.get_dummy_inputs(torch_device)
+
+        height_width_pairs = [(32, 32), (72, 56)]
+        for height, width in height_width_pairs:
+            expected_height = height - height % (pipe.vae_scale_factor * 2)
+            expected_width = width - width % (pipe.vae_scale_factor * 2)
+
+            inputs.update({"height": height, "width": width})
+            image = pipe(**inputs).images[0]
+            output_height, output_width, _ = image.shape
+            assert (output_height, output_width) == (expected_height, expected_width)