# Template-based handwriting scoring for preschool letters (pixel overlap / error ratio) — looking for metrics & related work

**URL:** https://forum.opencv.org/t/template-based-handwriting-scoring-for-preschool-letters-pixel-overlap-error-ratio-looking-for-metrics-related-work/24264
**Category:** Uncategorized
**Created:** [December 18, 2025, 7:02am UTC](https://forum.opencv.org/t/template-based-handwriting-scoring-for-preschool-letters-pixel-overlap-error-ratio-looking-for-metrics-related-work/24264 "2025-12-18T07:02:38Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Thiyara\_Gunawardena](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/thiyara_gunawardena/32/12807_2.png) [@Thiyara\_Gunawardena](https://forum.opencv.org/u/Thiyara_Gunawardena)
#### Post date: [December 18, 2025, 7:02am UTC](https://forum.opencv.org/t/template-based-handwriting-scoring-for-preschool-letters-pixel-overlap-error-ratio-looking-for-metrics-related-work/24264/1 "2025-12-18T07:02:38Z")

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Hi everyone,  
I’m working on a research component where I need to **score how accurately a preschool child wrote a single letter** (not just classify the letter). My supervisor wants a **novel scoring algorithm** rather than “train a CNN classifier.”

My current direction is **template-based** :

- Preprocess: binarize, center, normalize size, optionally skeletonize

- Have a “correct” template per letter

- Overlay student sample on template

- Compute an **error score** based on mismatch: e.g., parts of the sample outside the template (extra strokes) and parts of the template missing in the sample (missing strokes)

I’m looking for:

1. **Known metrics / approaches** for template overlap scoring (IoU / Dice / Chamfer / Hausdorff / DTW / skeleton-based distance, etc.)

2. Good keywords/papers for **handwriting quality scoring** or **shape similarity scoring** , especially for children

3. Ideas to make it more robust: alignment (Procrustes / ICP), stroke thickness normalization, skeleton graph matching, multi-view (raw + contour + skeleton) scoring

Also—my supervisor mentioned something like using a “ratio” (she referenced golden ratio as an example), so if there are **shape ratios/features** commonly used for letters (aspect ratios, curvature, symmetry, stroke proportion, loop size ratio), I’d love suggestions.

Thanks!