Poor 2D edge detection

Problem

Machine vision algorithms that rely on 2D edge detection, e.g., 2D template matching and barcode scanning, deliver poor results.

Causes

Low Resolution

Zivid 2 cameras feature a 2.3 MP image sensor. This resolution may not be sufficient for applications requiring precise edge detection or fine detail, such as 2D template matching or barcode scanning.

Legacy Demosaicing Algorithm

The demosaicing algorithm in Zivid 2 cameras, as well as Zivid 2+ M130, M60, and L110 cameras, can introduce image artifacts, including:

  • RGB aliasing: Unwanted green or pink pixels appear between high-contrast edges such as black and white lines.

  • Erroneous interpolation: Misinterpretation of pixel data can create inaccurate edge details.

  • Zipper effects: A stair-step pattern appears along diagonal or curved lines, further degrading edge quality.

These factors combined limit the performance of machine vision systems, especially in applications requiring high accuracy and sharp image features.

Possible Solution

We recommend upgrading to one of the Zivid 2+ MR30, MR60, or LR110 cameras for the best results. These models eliminate RGB aliasing and provide the sharpest and most reliable 2D image quality.

Upgrade to Zivid 2+

  1. Enhanced Image Sensor:

    Zivid 2+ cameras are equipped with a 5MP image sensor, which captures finer details. More pixels describe image features like edges with greater clarity, providing a competitive advantage in applications requiring precision.

  2. Improved Demosaicing Algorithm:

    A new demosaicing algorithm in the Zivid 2+ ensures superior edges and fine details. This enhancement significantly reduces artifacts, making images more reliable for analysis.

  3. Elimination of RGB Aliasing:

    Unlike Zivid 2 cameras, some Zivid 2+ cameras (specifically the MR30, MR60, and LR110) are engineered to avoid RGB aliasing. As a result, no unwanted green or pink pixels between black and white lines appear, ensuring accurate color reproduction.

Performance Comparison: Zivid 2 vs. Zivid 2+

The following images illustrate the improvements:

  • Left: Zivid 2

  • Center: Zivid 2+ M130

  • Right: Zivid 2+ MR130

All images are captured at a distance of 1.3 meters.

Barcode Lines

  • Zivid 2: Barcode lines appear blurry and blend with neighboring lines, often showing a noticeable zipper effect.

  • Zivid 2+ M130: Barcode lines are significantly sharper, with reduced blending but noticeable RGB aliasing between the lines.

  • Zivid 2+ MR130: Barcode lines are the sharpest, with no RGB aliasing. The black-and-white transitions are clean and precise.

../_images/2d_comparison_l100_m130_mr130_barcodes.png

Text Readability

  • Zivid 2: Text is blurry, making characters harder or impossible to read.

  • Zivid 2+ M130: Text is clearer but with noticeable RGB aliasing on the edges.

  • Zivid 2+ MR130: Text edges are sharp and crisp, with no RGB aliasing artifacts.

../_images/2d_comparison_l100_m130_mr130_text.png

Color Patterns

  • Zivid 2: Color patterns are blurry and often suffer from distortion due to RGB aliasing artifacts.

  • Zivid 2+ M130: Color patterns are sharper and better preserved but still suffering from RGB aliasing.

  • Zivid 2+ MR130: Provides the best results, ensuring vibrant and artifact-free color images.

../_images/2d_comparison_l100_m130_mr130_patterns.png