Implementation:Datajuicer Data juicer ImageFaceBlurMapper

Knowledge Sources	Datajuicer_Data_juicer
Domains	Data_Processing, Mapping
Last Updated	2026-02-14 16:00 GMT

Overview

Concrete tool for detecting and blurring faces in images for anonymization provided by Data-Juicer.

Description

ImageFaceBlurMapper is a mapper operator that uses an OpenCV Haar cascade classifier (default: haarcascade_frontalface_alt.xml) to detect face regions in images and applies a configurable blur type (mean, box, or Gaussian) with adjustable radius to each detected face bounding box. The blurred images are saved to a configurable output directory. Supports additional OpenCV detection parameters like scaleFactor, minNeighbors, minSize, and maxSize.

Usage

Use when you need to anonymize faces in training images for compliance with data protection regulations and for creating datasets where facial identity should not be exposed.

Code Reference

Source Location

• Repository: Datajuicer_Data_juicer
• File: data_juicer/ops/mapper/image_face_blur_mapper.py

Signature

@OPERATORS.register_module("image_face_blur_mapper")
class ImageFaceBlurMapper(Mapper):
    def __init__(self,
                 cv_classifier: str = "",
                 blur_type: str = "gaussian",
                 radius: NonNegativeFloat = 2,
                 save_dir: str = None,
                 *args, **kwargs):

Import

from data_juicer.ops.mapper.image_face_blur_mapper import ImageFaceBlurMapper

I/O Contract

Inputs

Name	Type	Required	Description
cv_classifier	str	No	OpenCV classifier path for face detection; defaults to haarcascade_frontalface_alt.xml
blur_type	str	No	Type of blur kernel: mean, box, or gaussian; defaults to "gaussian"
radius	NonNegativeFloat	No	Radius of blur kernel, defaults to 2
save_dir	str	No	Directory to store generated images; if not specified, saves in same directory as input

Outputs

Name	Type	Description
samples	Dict	Transformed samples with face-blurred image paths updated

Usage Examples

process:
  - image_face_blur_mapper:
      blur_type: "gaussian"
      radius: 2

Related Pages

• Environment:Datajuicer_Data_juicer_Python_Runtime_Environment