[ELMI2026] DEXEL versus PIXEL in imaging – a clear definition for a better understanding of light microscopy imaging systems
Authors/Creators
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1.
Max Planck Institute of Molecular Cell Biology and Genetics
- 2. INSCOPER
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3.
University of Massachusetts Chan Medical School
Contributors
Project member:
Description
This poster was presented at the ELMI2026 conference on June 17th 2026.
The work presented here is the result of intensive joint discussions among QUAREP-LiMi, especially Working Groups 2, 7, and 10.
When explaining digital resolution and spatial sampling rate, the term pixel almost inevitably comes up. A pixel (short for picture element) refers to the smallest non-divisible element of a digital image. Many such individual elements together make up an image that can for instance be displayed on a screen, explored numerically with a computer program, or shared across digital networks.
However, the term pixel is often used ambiguously, referring to both the unit elements of the image and the physical unit elements of a detector (e.g. a camera chip). This terminology can lead to confusion, especially when explaining resolution, image acquisition workflows, and reproducibility in light microscopy. This confusion can hinder a clear understanding of the relationship between detector characteristics, digital sampling, and image scale.
To address this ambiguity, QUAREP-LiMi is advocating for the use of the term dexel (short for detector element) to specifically designate the smallest detecting element of a physical detector. Each dexel collects information separately that will be converted to form a digital image composed of pixels.
We will explain how this terminology clearly separates the physical process of detection from the resulting digital image.
Furthermore, we will examine a range of image acquisition scenarios to demonstrate that the relationship between a dexel and a pixel is not inherently one-to-one. This will further illustrate that distinguishing between dexels and pixels clarifies the relationship between detection, sampling, and images in light microscopy.
We encourage all stakeholders—researchers, instrument developers, and educators—to adopt these definitions in order to promote a consistent and widely understood terminology and thus provide a better understanding of light microscopy imaging systems.