Add text-to-image generation support

Implemented complete text-to-image functionality across all AI providers:

Backend additions:
- Added text_to_image() method to AIProvider abstract class
- Implemented for all providers:
  * OpenAI: DALL-E generations API
  * Stability AI: SDXL text-to-image with negative prompts
  * Replicate: SDXL with full parameter control
  * Mock: Placeholder image generation for testing

New API endpoints (/generate):
- POST /generate/text-to-image
  * Generate image from prompt
  * Optional: create new project automatically
  * Configurable width/height (256-2048px)
  * Negative prompt support
  * Provider and model selection

- POST /generate/layer/text-to-image
  * Generate image as layer in existing project
  * Smaller dimensions for layer composition
  * Position control (x, y coordinates)
  * Saves to project layers directory

Features:
- Full provider support (OpenAI, Stability, Replicate, Mock)
- Negative prompts for better control
- Auto-project creation option
- Layer-based generation for compositing
- Dimension validation (256-2048px range)
- Model selection per request

Use cases:
- Create new images from scratch
- Generate elements to add as layers
- Quick ideation and iteration
- Base image creation for further editing

Next: Advanced canvas UI with layers and real-time preview
This commit is contained in:
Claude
2026-01-24 04:06:19 +00:00
parent fc394d76cf
commit 4b936b7a10
4 changed files with 407 additions and 1 deletions
+2 -1
View File
@@ -5,7 +5,7 @@ from contextlib import asynccontextmanager
from app.config import settings
from app.database import init_db
from app.routers import projects, edits, images, patches
from app.routers import projects, edits, images, patches, generate
@asynccontextmanager
@@ -36,6 +36,7 @@ app.include_router(projects.router)
app.include_router(edits.router)
app.include_router(images.router)
app.include_router(patches.router)
app.include_router(generate.router)
@app.get("/")
+176
View File
@@ -0,0 +1,176 @@
from fastapi import APIRouter, Depends, HTTPException, Form
from sqlalchemy.orm import Session
from typing import Optional
from PIL import Image
from io import BytesIO
import os
from app.database import get_db
from app.models.project import Project
from app.schemas import TextToImageRequest, TextToImageResponse
from app.services.ai_provider import get_ai_provider
from app.services.edit_service import EditService
from app.config import settings
router = APIRouter(prefix="/generate", tags=["generate"])
@router.post("/text-to-image", response_model=TextToImageResponse)
async def text_to_image(
prompt: str = Form(...),
width: int = Form(1024),
height: int = Form(1024),
negative_prompt: Optional[str] = Form(None),
ai_provider: Optional[str] = Form(None),
ai_model: Optional[str] = Form(None),
create_project: bool = Form(True),
project_name: Optional[str] = Form(None),
db: Session = Depends(get_db)
):
"""
Generate an image from text prompt
Args:
prompt: Text description of desired image
width: Image width (default 1024)
height: Image height (default 1024)
negative_prompt: What to avoid in generation
ai_provider: Override default AI provider
ai_model: Specific model to use
create_project: Whether to create a new project with the result
project_name: Name for the new project (if create_project=True)
Returns:
Generated image info and optionally project details
"""
# Validate dimensions
if width < 256 or width > 2048 or height < 256 or height > 2048:
raise HTTPException(
status_code=400,
detail="Width and height must be between 256 and 2048"
)
# Get AI provider
provider = get_ai_provider(ai_provider, ai_model)
try:
# Generate image
image_bytes = await provider.text_to_image(
prompt=prompt,
width=width,
height=height,
model=ai_model,
negative_prompt=negative_prompt
)
project_id = None
image_url = None
if create_project:
# Create a new project
project = Project(
name=project_name or f"Generated: {prompt[:50]}",
user_id=None # TODO: Add authentication
)
db.add(project)
db.commit()
db.refresh(project)
project_id = project.id
# Save image as both original and current
edit_service = EditService()
edit_service.ensure_project_dir(project_id)
original_path = edit_service.get_original_image_path(project_id)
current_path = edit_service.get_current_image_path(project_id)
# Save image
img = Image.open(BytesIO(image_bytes))
img.save(original_path, 'PNG')
img.save(current_path, 'PNG')
image_url = f"/projects/{project_id}/current"
return TextToImageResponse(
status="success",
prompt=prompt,
width=width,
height=height,
project_id=project_id,
image_url=image_url,
ai_provider=ai_provider or settings.ai_provider,
ai_model=ai_model
)
except Exception as e:
raise HTTPException(status_code=500, detail=str(e))
@router.post("/layer/text-to-image", response_model=TextToImageResponse)
async def text_to_image_layer(
project_id: int = Form(...),
prompt: str = Form(...),
width: int = Form(512),
height: int = Form(512),
x: int = Form(0),
y: int = Form(0),
negative_prompt: Optional[str] = Form(None),
ai_provider: Optional[str] = Form(None),
ai_model: Optional[str] = Form(None),
db: Session = Depends(get_db)
):
"""
Generate an image as a new layer in an existing project
This generates a smaller image that can be placed as a layer
on top of the current project canvas.
"""
# Verify project exists
project = db.query(Project).filter(Project.id == project_id).first()
if not project:
raise HTTPException(status_code=404, detail="Project not found")
# Get AI provider
provider = get_ai_provider(ai_provider, ai_model)
try:
# Generate image
image_bytes = await provider.text_to_image(
prompt=prompt,
width=width,
height=height,
model=ai_model,
negative_prompt=negative_prompt
)
# Save as temporary layer file
edit_service = EditService()
layers_dir = edit_service.get_project_dir(project_id) / "layers"
layers_dir.mkdir(exist_ok=True)
# Generate unique layer filename
import time
layer_filename = f"generated_{int(time.time())}.png"
layer_path = layers_dir / layer_filename
# Save layer image
with open(layer_path, 'wb') as f:
f.write(image_bytes)
return TextToImageResponse(
status="success",
prompt=prompt,
width=width,
height=height,
project_id=project_id,
image_url=f"/projects/{project_id}/layers/{layer_filename}",
layer_position={"x": x, "y": y},
ai_provider=ai_provider or settings.ai_provider,
ai_model=ai_model
)
except Exception as e:
raise HTTPException(status_code=500, detail=str(e))
+24
View File
@@ -107,6 +107,30 @@ class PatchApply(BaseModel):
feather_px: int = 5
# Text-to-Image schemas
class TextToImageRequest(BaseModel):
prompt: str
width: int = 1024
height: int = 1024
negative_prompt: Optional[str] = None
ai_provider: Optional[str] = None
ai_model: Optional[str] = None
create_project: bool = True
project_name: Optional[str] = None
class TextToImageResponse(BaseModel):
status: str
prompt: str
width: int
height: int
project_id: Optional[int] = None
image_url: Optional[str] = None
layer_position: Optional[Dict[str, int]] = None
ai_provider: str
ai_model: Optional[str] = None
# Generic responses
class StatusResponse(BaseModel):
status: str
+205
View File
@@ -36,6 +36,30 @@ class AIProvider(ABC):
"""
pass
@abstractmethod
async def text_to_image(
self,
prompt: str,
width: int = 1024,
height: int = 1024,
model: Optional[str] = None,
negative_prompt: Optional[str] = None
) -> bytes:
"""
Generate an image from text prompt
Args:
prompt: Text description of desired image
width: Image width in pixels
height: Image height in pixels
model: Optional specific model to use
negative_prompt: What to avoid in the generation
Returns:
Generated image as bytes
"""
pass
class OpenAIProvider(AIProvider):
"""OpenAI DALL-E 2 based image editing (NOTE: Lower quality than DALL-E 3)"""
@@ -88,6 +112,43 @@ class OpenAIProvider(AIProvider):
return image_response.content
async def text_to_image(
self,
prompt: str,
width: int = 1024,
height: int = 1024,
model: Optional[str] = None,
negative_prompt: Optional[str] = None
) -> bytes:
"""Generate image using OpenAI DALL-E"""
async with httpx.AsyncClient(timeout=60.0) as client:
data = {
'prompt': prompt,
'n': 1,
'size': f'{width}x{height}' if width == height else '1024x1024'
}
headers = {
'Authorization': f'Bearer {self.api_key}'
}
response = await client.post(
f"{self.base_url}/images/generations",
json=data,
headers=headers
)
response.raise_for_status()
result = response.json()
# Download the generated image
image_url = result['data'][0]['url']
image_response = await client.get(image_url)
image_response.raise_for_status()
return image_response.content
class StabilityAIProvider(AIProvider):
"""Stability AI based image editing (SDXL Inpainting)"""
@@ -154,6 +215,55 @@ class StabilityAIProvider(AIProvider):
image_data = result['artifacts'][0]['base64']
return base64.b64decode(image_data)
async def text_to_image(
self,
prompt: str,
width: int = 1024,
height: int = 1024,
model: Optional[str] = None,
negative_prompt: Optional[str] = None
) -> bytes:
"""Generate image using Stability AI SDXL"""
# Select model
model_key = model or self.default_model
engine_id = self.MODELS.get(model_key, self.MODELS['sdxl'])
async with httpx.AsyncClient(timeout=120.0) as client:
# Build prompts array
data = {
'text_prompts[0][text]': prompt,
'text_prompts[0][weight]': '1.0',
'cfg_scale': '7',
'samples': '1',
'steps': '50',
'height': str(height),
'width': str(width),
}
# Add negative prompt if provided
if negative_prompt:
data['text_prompts[1][text]'] = negative_prompt
data['text_prompts[1][weight]'] = '-1.0'
headers = {
'Authorization': f'Bearer {self.api_key}',
'Accept': 'application/json'
}
response = await client.post(
f"{self.base_url}/generation/{engine_id}/text-to-image",
data=data,
headers=headers
)
response.raise_for_status()
result = response.json()
# Decode base64 image
image_data = result['artifacts'][0]['base64']
return base64.b64decode(image_data)
class ReplicateProvider(AIProvider):
"""Replicate API with multiple model support"""
@@ -278,6 +388,77 @@ class ReplicateProvider(AIProvider):
raise Exception("Replicate prediction timed out")
async def text_to_image(
self,
prompt: str,
width: int = 1024,
height: int = 1024,
model: Optional[str] = None,
negative_prompt: Optional[str] = None
) -> bytes:
"""Generate image using Replicate SDXL"""
# Use SDXL for text-to-image
model_version = 'stability-ai/sdxl:39ed52f2a78e934b3ba6e2a89f5b1c712de7dfea535525255b1aa35c5565e08b'
async with httpx.AsyncClient(timeout=120.0) as client:
# Create prediction
prediction_data = {
"version": model_version,
"input": {
"prompt": prompt,
"width": width,
"height": height,
"num_outputs": 1,
"guidance_scale": 7.5,
"num_inference_steps": 50,
}
}
# Add negative prompt if provided
if negative_prompt:
prediction_data["input"]["negative_prompt"] = negative_prompt
headers = {
'Authorization': f'Bearer {self.api_key}',
'Content-Type': 'application/json'
}
# Start prediction
response = await client.post(
f"{self.base_url}/predictions",
json=prediction_data,
headers=headers
)
response.raise_for_status()
prediction = response.json()
# Poll for completion
prediction_url = prediction['urls']['get']
max_attempts = 60
attempt = 0
while attempt < max_attempts:
await asyncio.sleep(2)
status_response = await client.get(prediction_url, headers=headers)
status_response.raise_for_status()
status_data = status_response.json()
if status_data['status'] == 'succeeded':
# Download result image
output_url = status_data['output'][0]
image_response = await client.get(output_url)
image_response.raise_for_status()
return image_response.content
elif status_data['status'] == 'failed':
raise Exception(f"Replicate prediction failed: {status_data.get('error')}")
attempt += 1
raise Exception("Replicate text-to-image timed out")
class MockAIProvider(AIProvider):
"""Mock provider for testing (returns original patch)"""
@@ -294,6 +475,30 @@ class MockAIProvider(AIProvider):
"""Return the original patch (for testing)"""
return patch_image_bytes
async def text_to_image(
self,
prompt: str,
width: int = 1024,
height: int = 1024,
model: Optional[str] = None,
negative_prompt: Optional[str] = None
) -> bytes:
"""Generate a placeholder image (for testing)"""
from PIL import Image, ImageDraw, ImageFont
# Create a simple placeholder image
img = Image.new('RGB', (width, height), color='lightgray')
draw = ImageDraw.Draw(img)
# Draw text
text = f"Mock Image\n{width}x{height}\n{prompt[:50]}"
draw.text((width//4, height//2), text, fill='black')
# Convert to bytes
buffer = BytesIO()
img.save(buffer, format='PNG')
return buffer.getvalue()
def get_ai_provider(provider_name: Optional[str] = None, model: Optional[str] = None) -> AIProvider:
"""