Merge pull request #83 from bobab12/develop

Fix ArgumentCountError for grayscale images

Author: olivervogel

src/ColorProcessor.php

@@ -46,6 +46,14 @@ public function nativeToColor(mixed $native): ColorInterface
             throw new ColorException('Vips driver can only decode colors in array format.');
         }
 
+        // Handle grayscale images (single-band) when creating RgbColor
+        // VIPS returns single value for grayscale images, but RgbColor constructor needs 3 values
+        // Only grayscale images have single-band data; HSV/HSL would have 3 bands
+        if ($this->colorspace::class !== CmykColorspace::class && count($native) === 1) {
+            // Expand grayscale luminance to RGB triplet
+            $native = [$native[0], $native[0], $native[0]];
+        }
+
         return match ($this->colorspace::class) {
             CmykColorspace::class => new CmykColor(...$native),
             default => new RgbColor(...$native),

tests/Unit/Analyzers/PixelColorAnalyzerTest.php

@@ -42,4 +42,20 @@ public function testAnalyzeFloatFormat(): void
             $this->assertEquals('1eccff', $result->toHex(), 'Failed for format: ' . $format);
         }
     }
+
+    public function testAnalyzeGrayscale(): void
+    {
+        $image = $this->readTestImage('grayscale.png');
+        $analyzer = new PixelColorAnalyzer(0, 0);
+        $analyzer->setDriver(new Driver());
+        $result = $analyzer->analyze($image);
+        $this->assertInstanceOf(ColorInterface::class, $result);
+        // Grayscale images should return a color where R=G=B
+        $hex = $result->toHex();
+        $r = substr($hex, 0, 2);
+        $g = substr($hex, 2, 2);
+        $b = substr($hex, 4, 2);
+        $this->assertEquals($r, $g, 'Red and green channels should be equal for grayscale');
+        $this->assertEquals($g, $b, 'Green and blue channels should be equal for grayscale');
+    }
 }

tests/Unit/ColorProcessorTest.php

@@ -40,6 +40,18 @@ public function testNativeToColor(): void
         $this->assertEquals(255, $color->channel(Alpha::class)->value());
     }
 
+    public function testNativeToColorGrayscale(): void
+    {
+        // Test grayscale image handling - single value should be expanded to RGB
+        $processor = new ColorProcessor(new Colorspace());
+        $color = $processor->nativeToColor([128]); // Single grayscale value
+        $this->assertInstanceOf(Color::class, $color);
+        $this->assertEquals(128, $color->channel(Red::class)->value());
+        $this->assertEquals(128, $color->channel(Green::class)->value());
+        $this->assertEquals(128, $color->channel(Blue::class)->value());
+        $this->assertEquals(255, $color->channel(Alpha::class)->value()); // Default alpha
+    }
+
     #[DataProvider('interpretationToColorspaceProvider')]
     public function testInterpretationToColorspace(string $interpretation, string $colorspaceClassname): void
     {