a710328b5c
- Default density to thick (2) for bolder output - Default font size to 30pt for better readability - Add draw.fontmode="1" to disable antialiasing for crisp 1-bit text - Add ImageOps.autocontrast before thresholding images - Update web GUI defaults to match CLI
53 lines
1.7 KiB
Python
53 lines
1.7 KiB
Python
"""Image processing for Fichero D11s thermal label printer."""
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import logging
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from PIL import Image, ImageDraw, ImageFont, ImageOps
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from fichero.printer import PRINTHEAD_PX
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log = logging.getLogger(__name__)
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def prepare_image(img: Image.Image, max_rows: int = 240) -> Image.Image:
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"""Convert any image to 96px wide, 1-bit, black on white."""
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img = img.convert("L")
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w, h = img.size
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new_h = int(h * (PRINTHEAD_PX / w))
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if new_h > max_rows:
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log.warning("Image height %dpx exceeds max %dpx, cropping bottom", new_h, max_rows)
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new_h = max_rows
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img = img.resize((PRINTHEAD_PX, new_h), Image.LANCZOS)
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img = ImageOps.autocontrast(img, cutoff=1)
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img = img.point(lambda x: 1 if x < 128 else 0, "1")
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return img
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def image_to_raster(img: Image.Image) -> bytes:
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"""Pack 1-bit image into raw raster bytes, MSB first."""
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if img.mode != "1":
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raise ValueError(f"Expected mode '1', got '{img.mode}'")
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if img.width != PRINTHEAD_PX:
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raise ValueError(f"Expected width {PRINTHEAD_PX}, got {img.width}")
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return img.tobytes()
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def text_to_image(text: str, font_size: int = 30, label_height: int = 240) -> Image.Image:
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"""Render crisp 1-bit text, rotated 90 degrees for label printing."""
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canvas_w = label_height
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canvas_h = PRINTHEAD_PX
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img = Image.new("L", (canvas_w, canvas_h), 255)
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draw = ImageDraw.Draw(img)
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draw.fontmode = "1" # disable antialiasing - pure 1-bit glyph rendering
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font = ImageFont.load_default(size=font_size)
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bbox = draw.textbbox((0, 0), text, font=font)
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tw, th = bbox[2] - bbox[0], bbox[3] - bbox[1]
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x = (canvas_w - tw) // 2
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y = (canvas_h - th) // 2
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draw.text((x, y), text, fill=0, font=font)
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img = img.rotate(90, expand=True)
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return img
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