TheAlgorithms/Java · error · IllegalArgumentException

hue should be between 0 and 360

Error message

hue should be between 0 and 360

What it means

Thrown by RgbHsvConversion.hsvToRgb when the hue parameter is less than 0 or greater than 360. Hue is measured in degrees on the color wheel and the valid range is [0, 360]; values outside this range are geometrically meaningless for the hue-section calculation (hue / 60).

Source

Thrown at src/main/java/com/thealgorithms/conversions/RgbHsvConversion.java:60

        assert approximatelyEqualHsv(rgbToHsv(0, 255, 0), new double[] {120, 1, 1});
        assert approximatelyEqualHsv(rgbToHsv(0, 0, 255), new double[] {240, 1, 1});
        assert approximatelyEqualHsv(rgbToHsv(255, 0, 255), new double[] {300, 1, 1});
        assert approximatelyEqualHsv(rgbToHsv(64, 128, 128), new double[] {180, 0.5, 0.5});
        assert approximatelyEqualHsv(rgbToHsv(193, 196, 224), new double[] {234, 0.14, 0.88});
        assert approximatelyEqualHsv(rgbToHsv(128, 32, 80), new double[] {330, 0.75, 0.5});
    }

    /**
     * Conversion from the HSV-representation to the RGB-representation.
     *
     * @param hue Hue of the color.
     * @param saturation Saturation of the color.
     * @param value Brightness-value of the color.
     * @return The tuple of RGB-components.
     */
    public static int[] hsvToRgb(double hue, double saturation, double value) {
        if (hue < 0 || hue > 360) {
            throw new IllegalArgumentException("hue should be between 0 and 360");
        }

        if (saturation < 0 || saturation > 1) {
            throw new IllegalArgumentException("saturation should be between 0 and 1");
        }

        if (value < 0 || value > 1) {
            throw new IllegalArgumentException("value should be between 0 and 1");
        }

        double chroma = value * saturation;
        double hueSection = hue / 60;
        double secondLargestComponent = chroma * (1 - Math.abs(hueSection % 2 - 1));
        double matchValue = value - chroma;

        return getRgbBySection(hueSection, chroma, matchValue, secondLargestComponent);
    }

View on GitHub (pinned to fdfb9a395b)

Solutions

1. Clamp hue to [0, 360] using Math.max(0, Math.min(360, hue)) before calling hsvToRgb.
2. Normalize hue with modulo: hue = ((hue % 360) + 360) % 360, which wraps out-of-range values into the valid interval.
3. Validate at the UI boundary that the slider or input field constrains hue to [0, 360].

Example fix

// before
int[] rgb = RgbHsvConversion.hsvToRgb(hue, sat, val);

// after
hue = ((hue % 360) + 360) % 360; // wrap into [0, 360)
int[] rgb = RgbHsvConversion.hsvToRgb(hue, sat, val);

hue = ((hue % 360) + 360) % 360; // wrap into [0, 360)
int[] rgb = RgbHsvConversion.hsvToRgb(hue, saturation, value);

static boolean isValidHue(double hue) {
    return hue >= 0 && hue <= 360;
}

try {
    int[] rgb = RgbHsvConversion.hsvToRgb(hue, saturation, value);
} catch (IllegalArgumentException e) {
    // hue out of range; normalize and retry
    hue = ((hue % 360) + 360) % 360;
    int[] rgb = RgbHsvConversion.hsvToRgb(hue, saturation, value);
}

When it happens

Trigger: Passing a negative hue value or a hue greater than 360. Supplying hue from a UI color picker that allows out-of-range values. Computing hue from a formula that can produce values outside [0, 360] (e.g., an unnormalized arctangent result).

Common situations: A color picker slider is configured without min/max constraints. Hue is computed from image processing code that can produce values slightly outside the expected range. User-entered HSV values are passed through without clamping.

Related errors

• saturation should be between 0 and 1
• value should be between 0 and 1
• red should be between 0 and 255
• green should be between 0 and 255
• blue should be between 0 and 255

AI-assisted analysis of TheAlgorithms/Java@fdfb9a395b (2026-08-13). Data as JSON: /api/errors/d88b007adfe501cc. Report an issue: GitHub.