Final preparation

The last step is to expand the dataset with augmentations, optionally upscale images, and produce resized versions at the dimensions you need for training.

Augment

The augment command increases dataset size by applying image transformations. It reads from one or more source folders and writes the transformed images (plus the originals by default) to a destination folder.

To create the final 1024px dataset with horizontal flips (2x the images):

dtst augment -d scratch/crowd --from select --to final/1024 --flipX

You can combine multiple transforms in a single run. This produces the original plus three variants of each image (4x the dataset):

dtst augment -d scratch/crowd --from select --to final/1024 --flipX --flipY --flipXY

If you only want the transformed images without copying the originals:

dtst augment -d scratch/crowd --from select --to final/1024 --flipX --no-copy

Upscale

The upscale command increases image resolution using AI super-resolution models. This is useful when source images are too small for your target training resolution — for example, face crops that came out at 256px but you need 1024px.

To upscale images 4x (the default):

dtst upscale -d scratch/crowd --from final/1024 --to final/upscaled

For 2x upscaling:

dtst upscale -d scratch/crowd --from final/1024 --to final/upscaled --scale 2

The default 4x model (Real-ESRGAN) tends to smooth out textures, especially on noisy source images. Use --denoise to control how much denoising is applied. Lower values preserve more natural texture, which is particularly important for face datasets:

dtst upscale -d scratch/crowd --from final/1024 --to final/upscaled --denoise 0

The --denoise option accepts a value between 0.0 and 1.0:

• 0.0 — maximum texture preservation (recommended for faces)
• 0.5 — balanced
• 1.0 — full denoising (smoothest result)

Note that --denoise is only available with 4x upscaling and activates a different, lighter model (realesr-general-x4v3). It cannot be combined with --model or --scale 2.

Large images are processed in tiles to avoid GPU memory issues. If you run into out-of-memory errors, reduce the tile size:

dtst upscale -d scratch/crowd --from final/1024 --to final/upscaled --tile-size 256

Resize

The frame command resizes images to a target width and/or height using Lanczos resampling. Use it to produce smaller versions of the augmented dataset:

dtst frame -d scratch/crowd --from final/1024 --to final/512 --width 512 --height 512
dtst frame -d scratch/crowd --from final/1024 --to final/256 --width 256 --height 256

When only one dimension is given, the other is computed proportionally to preserve the aspect ratio:

dtst frame -d scratch/crowd --from final/1024 --to final/512 --width 512

Final directory

crowd.yaml
scratch/
  crowd/
    results.jsonl
    images/
      search1/
      search2/
      frames/
    videos/
    faces/
    cluster/
      000/
      001/
      noise/
    select/
    final/
      1024/              <- augmented originals
      upscaled/          <- AI-upscaled (optional)
      512/               <- resized to 512px
      256/               <- resized to 256px