How to Scan OMR Sheets

How to Scan OMR Sheets

After students complete their paper-based exams, scan the filled OMR sheets to automatically grade them. Course37's Dynamic OCR Algorithm achieves 99%+ accuracy across all paper sets.

Prerequisites

• A standard flatbed or sheet-feed scanner (any brand works)
• Scanning at 300 DPI recommended (minimum 200 DPI)
• Grayscale or Color mode (both work; grayscale is faster)
• Filled OMR sheets from your OMR template

Step-by-Step Scanning Process

Step 1 — Scan the Sheets

1. Collect all filled OMR sheets from the exam
2. Scan them using your scanner as:
   • Individual images — JPEG or PNG (one file per sheet)
   • Multi-page PDF — All sheets in one PDF file
3. Recommended: 300 DPI, grayscale

Step 2 — Upload to Course37

1. Go to Exams → OMR → Scan Results
2. Select the Exam this scan belongs to
3. Select the OMR Template that was used
4. Upload the scanned files — drag and drop supported
5. You can upload multiple files at once

📸 Screenshot: OMR upload interface with drag-and-drop

Step 3 — Automated Processing

Our Dynamic OCR Algorithm processes each sheet:

1. Detects orientation — Handles slightly rotated or misaligned papers
2. Identifies student — Reads the student ID/roll number field
3. Detects filled bubbles — Reads each question's selected answer
4. Identifies set — Determines which set (A, B, C, D) was used
5. Calculates score — Compares answers against the answer key

📸 Screenshot: Processing progress with detected answers overlay

Step 4 — Review Results

1. After processing, review the parsed results
2. Each sheet shows:
   • Scanned image overlay with detected marks
   • Detected vs. expected answers per question
   • Confidence level for each detection
3. Flag low-confidence detections — These need manual verification
4. Correct any misdetections manually if needed

Step 5 — Confirm

1. After reviewing, click Confirm Results
2. Results are saved and ready for publishing

Accuracy & Edge Cases

The Dynamic OCR Algorithm handles challenging scenarios:

Overall accuracy: 99%+ across all paper sets and scanning conditions.

Scanning Tips for Best Results

1. Use 300 DPI — Higher resolution = higher accuracy
2. Clean scanner glass — Dust and smudges affect detection
3. Flatten sheets — Crumpled papers may scan poorly
4. Consistent orientation — Feed all sheets the same way
5. Batch scan — Use a sheet-feed scanner for faster processing

Related Articles

• How to Create an OMR Template — Design answer sheets
• How to Manage OMR Results — Review and publish results
• How to See Results — Exam results management