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Extractors Reference

Extractors are tools for analyzing and extracting information from colors. This reference covers the extractor system in Negarity Color.

Available Extractors​

The Negarity Color library includes extractors in the Extractor/Analysis namespace:

Analysis Extractors​

These extractors provide color analysis capabilities:

ExtractorClassDescription
Contrast AnalyzerContrastAnalyzerAnalyzes color contrast ratios
Delta E AnalyzerDeltaEAnalyzerCalculates perceptual color difference (ΔE)
Luminance AnalyzerLuminanceAnalyzerCalculates relative luminance

Using Extractors​

Extractors are typically used to analyze color properties:

use Negarity\Color\Extractor\Analysis\LuminanceAnalyzer;
use Negarity\Color\Color;

$color = Color::rgb(255, 100, 50);
$analyzer = new LuminanceAnalyzer();
$luminance = $analyzer->analyze($color);

Extractor Interface​

All extractors implement the ExtractorInterface:

interface ExtractorInterface
{
    public function extract(ColorInterface $color): mixed;
}

Common Use Cases​

Color Contrast Analysis​

use Negarity\Color\Extractor\Analysis\ContrastAnalyzer;

$color1 = Color::rgb(255, 255, 255); // White
$color2 = Color::rgb(0, 0, 0);       // Black

$analyzer = new ContrastAnalyzer();
$contrast = $analyzer->getContrastRatio($color1, $color2);
// Returns contrast ratio (e.g., 21:1 for black/white)

Color Difference Analysis​

use Negarity\Color\Extractor\Analysis\DeltaEAnalyzer;

$color1 = Color::rgb(255, 100, 50);
$color2 = Color::rgb(250, 105, 55);

$analyzer = new DeltaEAnalyzer();
$deltaE = $analyzer->calculate($color1, $color2);
// Returns perceptual color difference

Luminance Analysis​

use Negarity\Color\Extractor\Analysis\LuminanceAnalyzer;

$color = Color::rgb(255, 100, 50);
$analyzer = new LuminanceAnalyzer();
$luminance = $analyzer->analyze($color);
// Returns relative luminance (0.0 to 1.0)

Creating Custom Extractors​

To create a custom extractor, implement the ExtractorInterface:

use Negarity\Color\ColorInterface;
use Negarity\Color\Extractor\ExtractorInterface;

class MyCustomExtractor implements ExtractorInterface
{
    public function extract(ColorInterface $color): mixed
    {
        // Your extraction logic
        return $result;
    }
}

See Also​