Table 3 Data preparation and splitting.

From: SpinachXAI-Rec: a multi-stage explainable AI framework for spinach freshness classification and consumer recommendation

Process stage

Description

Augmentation Techniques

RandomRotate90, HorizontalFlip, VerticalFlip, BrightnessContrast, GaussNoise, MotionBlur, HueSaturationValue, RandomGamma, ElasticTransform

Preprocessing Pipeline

Resizing, RGB conversion, denoising, contrast & color normalization, histogram scaling

Image Resize

224 × 224 pixels (resized from original size)

Color Space Conversion

Converted from BGR to RGB using OpenCV for color fidelity

Brightness Normalization

Standardized to a consistent mean-brightness histogram per image

Noise Handling

Gaussian and motion noise reduced; synthetic noise applied for generalization

Train-Test Split

Split into 70% train (8400 images) and 30% test (3600 images), stratified across all 6 classes

Training Sample Size

8400 images (1400 per class × 6 classes)

Testing Sample Size

3600 images (600 per class × 6 classes)

Train Class Balance

Even class distribution (Malabar, Red, Water × Fresh/Non-Fresh)

Test Class Balance

Preserved balance across six classes in unseen data

Train RGB Statistics

R: 180–210, G: 175–205, B: 160–200 (mean ± 10); normalized between 0–1

Test RGB Statistics

R: 175–205, G: 170–200, B: 160–195 (mean ± 10); normalized between 0–1