---
title: "Histogram tracker"
slug: "histogram-operator"
updated: 2025-04-22T12:54:47Z
published: 2025-04-22T12:54:47Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://composer.docs.vindral.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Histogram tracker

**Trackers/Histogram**

The **Histogram Operator** is a powerful real-time tool for analyzing video content based on content colors (hue, saturation and value, or HSV in short).

The core of the operator has one major function: **count the number of instances of each unique color**. This calculation can also be described as a **HSV-histogram**: A histogram is a mathematical representation of how common a certain value is. In this case, the histograms keeps track of the most common color = hue, saturation and value (HSV).

The operator is very flexible and can be used in many different ways and in many use-cases. This flexibility comes with a bit of a drawback: complexity. This operator is one of the most complex operators to describe and to understand.

The best way of thinking of this operator is as if it were a "filter": you define an HSV selection and additional criteria, and if those are fulfilled the operator will consider your content (video frame) to be **qualified**. If your criterias also include a **Temporal filter** (content over time), the operator will analyze the content over a number of frames and provide additional options for the content to be qualified.

The video analysis engine of the operator can be restricted to a certain part of the video (Processing Area).

![](https://cdn.document360.io/94808959-fd66-406c-ab5e-4691ce952a14/Images/Documentation/operator_histogram_qualified_240904.png)

The configuration below will detect a green area and show the qualified pixels as pink (To see the qualified pink pixels, uncheck the “Video pass-through” checkbox). Unchecking the “Show qualified pixels” will still detect the green pixels but not visually show them as pink. ![HistogramOperatorV2.png](https://cdn.document360.io/94808959-fd66-406c-ab5e-4691ce952a14/Images/Documentation/operator_histogram_240905.png)

- **Configuration** In this section, you define the criteria, or "filters", for qualifying pixels.
  - **Minimum hue value** - the minimum hue (0-360)
  - **Maximum hue value** - the maximum hue (0-360)
  - **Minimum saturation** - the minimum saturation (0-100 %)
  - **Maximin saturation** - the maximum saturation (0-100 %)
  - **Maximum value** - the maximum value (0 - 100%)
  - **Minimum detection percentage** - defines the minimum percentage of pixels that needs to qualify.
- **Visualization**
  - **Show qualifying pixels** - when selected, all qualifying pixels will be shown as **pink**pixels.
  - **Hide disqualifying pixels** - when selected, all pixels that don’t qualify will be hidden.
  - **Hide all output** - hides all pixels that are being processed.
- **Temporal filter (time)**
  - **Consecutive Qualify Frames** - the number of consequent frames that needs to qualify for the Temporal Qualified check to pass (become true).
  - **Consecutive Un-qualify Frames** - the number of consequent frames that needs to be disqualified for the Temporal Qualified check to pass (become true).
- **Results**
  - **Qualified** - true/checked if the frame qualified.
  - **Temporal Qualified** - true/checked if the frame is qualified using the temporal filter.
  - **Most common hue** - the most common hue in the frame
  - **Count** - the number of pixels having the most common hue
  - **Number of hue values** - the number of unique hue values
  - **Most common saturation** - the most common saturation in the frame
  - **Number of saturation values** - the number of unique saturation values
- **Summary**
  - **Total number of pixels analyzed**
  - **Total number of pixels processed**
  - **Percent processed**
- **Processing area**
  - **Video-pass-through** - when selected, the operator will not make any visual changes to the image.
  - **Left** - crop left
  - **Right** - crop right
  - **Top** - crop top
  - **Bottom** - crop bottom

## Tutorial

One example on how to use the Histogram operator can be found in the [Roulette Replay tutorial](/v1/docs/tutorials).