thats-me/dev/tools/backgrounds/generate_photo.py

#!/usr/bin/env python3
"""Generates the photographic LifeWave backgrounds with Gemini (Nano Banana 2).

Square, because the app crops with `cover` in both orientations. Every
prompt asks for an empty middle band and no focal point: the wave and its
dots are the subject, the background only sets the mood.

Usage: python3 generate_photo.py [name ...]   (default: all five)
"""
import os, sys, time

sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'lifeline-images'))
from gemini import generate  # noqa: E402

ROOT = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
OUT = os.path.join(ROOT, 'dev', 'backgrounds', 'photo')

COMMON = (' Square format, fills the frame edge to edge. No text, no watermark, no people, no animals, '
          'no buildings, no objects. The centre band of the image is calm and almost uniform, because a '
          'thin glowing line will be drawn over it later. Photographic, subdued, low contrast, fine grain.')

PROMPTS = {
    # Second pass: the graphic ideas rendered as photographed material, so
    # they carry inner detail without gaining a subject.
    '01-tinte': (
        'Macro photograph of the surface of deep charcoal-black handmade paper washed with black ink, so close that '
        'the paper extends beyond every edge of the frame, no sheet edges, no border, no background. '
        'Subtle mottled variations of anthracite and graphite, faint cotton fibres visible on close inspection, '
        'a soft darker vignette towards the edges, raking light from the upper left giving the surface a gentle '
        'matte relief. Nothing written on it, no objects.' + COMMON),
    '02-goldstaub': (
        'Macro photograph of fine gold dust and a few tiny gold leaf flakes scattered on dark anthracite velvet. '
        'The dust gathers along the bottom edge and thins out quickly upwards, the upper two thirds of the frame '
        'are almost empty dark velvet with only a handful of distant specks. Warm gold reflections, very shallow '
        'depth of field so most specks are soft bokeh. Elegant, dark, sparse.' + COMMON),
    '03-horizont': (
        'Minimalist photograph of a vast empty plain at the very end of dusk. Black featureless land in the lower '
        'third, a deep graphite night sky above, and between them only a thin, soft band of warm amber and gold '
        'afterglow along the horizon at two thirds of the height. No sun, no clouds, no trees, no lights. '
        'Cinematic, very dark, the glow is the only colour.' + COMMON),
    '04-papier': (
        'Macro photograph of the surface of warm cream handmade cotton paper, so close that the paper extends beyond '
        'every edge of the frame, no sheet edges, no deckle edge, no border, no background. Soft uneven surface with '
        'fine fibres, lit with raking light from the side so the texture shows as gentle relief, a subtle '
        'darker vignette in the corners. No writing, no lines, no objects, no folds.' + COMMON),
    '05-leinen': (
        'Photograph of heavy dark charcoal-grey linen with a visible slub weave, lit from the side so the threads '
        'catch a faint warm sheen. The fabric lies flat and even across the whole frame, no folds, no creases, no '
        'seams, only the weave itself with a very gentle variation of light. Rich, tactile, dark, low contrast.' + COMMON),
    '06a-aquarell-warm': (
        'Extreme close-up of a watercolour wash on cold-pressed paper, the paper runs beyond every edge of the '
        'frame, no border, no tape marks, no stripes, no bands, one continuous sheet. Blooms of warm sepia, golden '
        'ochre and a little dusty indigo pigment gather in the corners with visible granulation and soft '
        'cauliflower edges, the middle stays pale warm cream. No shapes, no drips, no splatter.' + COMMON),
    '06b-aquarell-dunkel': (
        'Extreme close-up of an ink wash on heavy paper, the paper runs beyond every edge of the frame, no border. '
        'Deep indigo and graphite ink bleeds in from the top and bottom edges with visible granulation, the '
        'middle band softens into a muted grey-blue wash, tiny specks of gold pigment caught in the darker '
        'areas. Moody, dark overall. No shapes, no drips.' + COMMON),
    '07-kohle': (
        'Photograph of a dark slate chalkboard surface, matte anthracite with a faint haze of chalk dust and the '
        'ghost traces of wiped chalk strokes near the top and bottom edges, the centre almost clean. Fine mineral '
        'texture of the slate visible up close, soft even light.' + COMMON),
    '08-nebel': (
        'Photograph of gentle hills at dawn in dense morning fog, almost monochrome grey-blue, dark toned. '
        'A faint treeline is barely visible at the very bottom, the rest of the frame is soft, empty fog with a '
        'slight brightening towards the top. No sun, no sky detail.' + COMMON),
    '09-daemmerung': (
        'Long-exposure photograph of a calm sea at dusk. The horizon sits in the lower third. Deep blue-grey '
        'sky above fading into a narrow warm amber band right at the horizon, perfectly smooth water below, '
        'darker than the sky. No sun disc, no detailed clouds, no boats, no shore.' + COMMON),
    '10-nachthimmel': (
        'Photograph of a deep midnight-blue night sky turning to black, with faint thin wisps of high cloud. '
        'No stars, no moon, no ground, no horizon, no light source. A smooth dark gradient with a hint of '
        'texture from the clouds.' + COMMON),
}

if __name__ == '__main__':
    names = sys.argv[1:] or list(PROMPTS)
    os.makedirs(OUT, exist_ok=True)
    for name in names:
        out = os.path.join(OUT, f'{name}.jpg')
        for size in ('2K', '1K'):
            try:
                generate(PROMPTS[name], out=out, aspect='1:1', size=size)
                print(out, size, os.path.getsize(out) // 1024, 'KB')
                break
            except RuntimeError as error:
                print(name, size, 'failed:', str(error)[:200])
        time.sleep(2)