From f035f7d516b7fa32bd4f867c351dd69c0b4a65b8 Mon Sep 17 00:00:00 2001
From: Oliver Vogel <oliver@olivervogel.com>
Date: Mon, 25 Mar 2024 19:46:16 +0100
Subject: [PATCH] Trim Modifier (#1322)

Co-authored-by: Sibin Grasic <sibin.grasic@oblak.studio>
---
 src/Drivers/Gd/Modifiers/TrimModifier.php     |  82 ++++++++++++++++++
 .../Imagick/Modifiers/TrimModifier.php        |  26 ++++++
 src/Image.php                                 |  11 +++
 src/Interfaces/ImageInterface.php             |  11 +++
 src/Modifiers/TrimModifier.php                |  14 +++
 .../Drivers/Gd/Modifiers/TrimModifierTest.php |  55 ++++++++++++
 .../Imagick/Modifiers/TrimModifierTest.php    |  55 ++++++++++++
 tests/resources/radial.png                    | Bin 0 -> 1254 bytes
 8 files changed, 254 insertions(+)
 create mode 100644 src/Drivers/Gd/Modifiers/TrimModifier.php
 create mode 100644 src/Drivers/Imagick/Modifiers/TrimModifier.php
 create mode 100644 src/Modifiers/TrimModifier.php
 create mode 100644 tests/Unit/Drivers/Gd/Modifiers/TrimModifierTest.php
 create mode 100644 tests/Unit/Drivers/Imagick/Modifiers/TrimModifierTest.php
 create mode 100644 tests/resources/radial.png

diff --git a/src/Drivers/Gd/Modifiers/TrimModifier.php b/src/Drivers/Gd/Modifiers/TrimModifier.php
new file mode 100644
index 00000000..7c011e0d
--- /dev/null
+++ b/src/Drivers/Gd/Modifiers/TrimModifier.php
@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Drivers\Gd\Modifiers;
+
+use Intervention\Image\Exceptions\AnimationException;
+use Intervention\Image\Exceptions\NotSupportedException;
+use Intervention\Image\Exceptions\RuntimeException;
+use Intervention\Image\Geometry\Point;
+use Intervention\Image\Interfaces\ImageInterface;
+use Intervention\Image\Interfaces\SpecializedInterface;
+use Intervention\Image\Modifiers\TrimModifier as GenericTrimModifier;
+
+class TrimModifier extends GenericTrimModifier implements SpecializedInterface
+{
+    public function apply(ImageInterface $image): ImageInterface
+    {
+        if ($image->isAnimated()) {
+            throw new NotSupportedException('Trim modifier cannot be applied to animated images.');
+        }
+
+        // apply tolerance with a min. value of .5 because the default tolerance of '0' should
+        // already trim away similar colors which is not the case with imagecropauto.
+        $trimmed = imagecropauto(
+            $image->core()->native(),
+            IMG_CROP_THRESHOLD,
+            max([.5, $this->tolerance / 10]),
+            $this->trimColor($image)
+        );
+
+        // if the tolerance is very high, it is possible that no image is left.
+        // imagick returns a 1x1 pixel image in this case. this does the same.
+        if ($trimmed === false) {
+            $trimmed = $this->driver()->createImage(1, 1)->core()->native();
+        }
+
+        $image->core()->setNative($trimmed);
+
+        return $image;
+    }
+
+    /**
+     * Create an average color from the colors of the four corner points of the given image
+     *
+     * @param ImageInterface $image
+     * @throws RuntimeException
+     * @throws AnimationException
+     * @return int
+     */
+    private function trimColor(ImageInterface $image): int
+    {
+        // trim color base
+        $red = 0;
+        $green = 0;
+        $blue = 0;
+
+        // corner coordinates
+        $size = $image->size();
+        $cornerPoints = [
+            new Point(0, 0),
+            new Point($size->width() - 1, 0),
+            new Point(0, $size->height() - 1),
+            new Point($size->width() - 1, $size->height() - 1),
+        ];
+
+        // create an average color to be used in trim operation
+        foreach ($cornerPoints as $pos) {
+            $cornerColor = imagecolorat($image->core()->native(), $pos->x(), $pos->y());
+            $rgb = imagecolorsforindex($image->core()->native(), $cornerColor);
+            $red += round(round(($rgb['red'] / 51)) * 51);
+            $green += round(round(($rgb['green'] / 51)) * 51);
+            $blue += round(round(($rgb['blue'] / 51)) * 51);
+        }
+
+        $red = (int) round($red / 4);
+        $green = (int) round($green / 4);
+        $blue = (int) round($blue / 4);
+
+        return imagecolorallocate($image->core()->native(), $red, $green, $blue);
+    }
+}
diff --git a/src/Drivers/Imagick/Modifiers/TrimModifier.php b/src/Drivers/Imagick/Modifiers/TrimModifier.php
new file mode 100644
index 00000000..88bc46a2
--- /dev/null
+++ b/src/Drivers/Imagick/Modifiers/TrimModifier.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Drivers\Imagick\Modifiers;
+
+use Intervention\Image\Exceptions\NotSupportedException;
+use Intervention\Image\Interfaces\ImageInterface;
+use Intervention\Image\Interfaces\SpecializedInterface;
+use Intervention\Image\Modifiers\TrimModifier as GenericTrimModifier;
+
+class TrimModifier extends GenericTrimModifier implements SpecializedInterface
+{
+    public function apply(ImageInterface $image): ImageInterface
+    {
+        if ($image->isAnimated()) {
+            throw new NotSupportedException('Trim modifier cannot be applied to animated images.');
+        }
+
+        $imagick = $image->core()->native();
+        $imagick->trimImage(($this->tolerance / 100 * $imagick->getQuantum()) / 1.5);
+        $imagick->setImagePage(0, 0, 0, 0);
+
+        return $image;
+    }
+}
diff --git a/src/Image.php b/src/Image.php
index 21fe3665..c336fc2b 100644
--- a/src/Image.php
+++ b/src/Image.php
@@ -88,6 +88,7 @@ use Intervention\Image\Modifiers\ScaleModifier;
 use Intervention\Image\Modifiers\SharpenModifier;
 use Intervention\Image\Modifiers\SliceAnimationModifier;
 use Intervention\Image\Modifiers\TextModifier;
+use Intervention\Image\Modifiers\TrimModifier;
 use Intervention\Image\Typography\FontFactory;
 
 final class Image implements ImageInterface
@@ -749,6 +750,16 @@ final class Image implements ImageInterface
         return $this->modify(new CropModifier($width, $height, $offset_x, $offset_y, $background, $position));
     }
 
+    /**
+     * {@inheritdoc}
+     *
+     * @see ImageInterface::trim()
+     */
+    public function trim(int $tolerance = 0): ImageInterface
+    {
+        return $this->modify(new TrimModifier($tolerance));
+    }
+
     /**
      * {@inheritdoc}
      *
diff --git a/src/Interfaces/ImageInterface.php b/src/Interfaces/ImageInterface.php
index 22be2360..48357881 100644
--- a/src/Interfaces/ImageInterface.php
+++ b/src/Interfaces/ImageInterface.php
@@ -6,6 +6,7 @@ namespace Intervention\Image\Interfaces;
 
 use Countable;
 use Intervention\Image\Encoders\AutoEncoder;
+use Intervention\Image\Exceptions\AnimationException;
 use Intervention\Image\Exceptions\RuntimeException;
 use Intervention\Image\Origin;
 use IteratorAggregate;
@@ -615,6 +616,16 @@ interface ImageInterface extends IteratorAggregate, Countable
         string $position = 'top-left'
     ): self;
 
+    /**
+     * Trim the image by removing border areas of similar color within a the given tolerance
+     *
+     * @param int $tolerance
+     * @throws RuntimeException
+     * @throws AnimationException
+     * @return ImageInterface
+     */
+    public function trim(int $tolerance = 0): self;
+
     /**
      * Place another image into the current image instance
      *
diff --git a/src/Modifiers/TrimModifier.php b/src/Modifiers/TrimModifier.php
new file mode 100644
index 00000000..89fa3992
--- /dev/null
+++ b/src/Modifiers/TrimModifier.php
@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Modifiers;
+
+use Intervention\Image\Drivers\SpecializableModifier;
+
+class TrimModifier extends SpecializableModifier
+{
+    public function __construct(public int $tolerance = 0)
+    {
+    }
+}
diff --git a/tests/Unit/Drivers/Gd/Modifiers/TrimModifierTest.php b/tests/Unit/Drivers/Gd/Modifiers/TrimModifierTest.php
new file mode 100644
index 00000000..c85c8c88
--- /dev/null
+++ b/tests/Unit/Drivers/Gd/Modifiers/TrimModifierTest.php
@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests\Unit\Drivers\Gd\Modifiers;
+
+use Intervention\Image\Exceptions\NotSupportedException;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\RequiresPhpExtension;
+use Intervention\Image\Modifiers\TrimModifier;
+use Intervention\Image\Tests\GdTestCase;
+
+#[RequiresPhpExtension('gd')]
+#[CoversClass(\Intervention\Image\Modifiers\TrimModifier::class)]
+#[CoversClass(\Intervention\Image\Drivers\Gd\Modifiers\TrimModifier::class)]
+final class TrimModifierTest extends GdTestCase
+{
+    public function testTrim(): void
+    {
+        $image = $this->readTestImage('trim.png');
+        $this->assertEquals(50, $image->width());
+        $this->assertEquals(50, $image->height());
+        $image->modify(new TrimModifier());
+        $this->assertEquals(28, $image->width());
+        $this->assertEquals(28, $image->height());
+    }
+
+    public function testTrimGradient(): void
+    {
+        $image = $this->readTestImage('radial.png');
+        $this->assertEquals(50, $image->width());
+        $this->assertEquals(50, $image->height());
+        $image->modify(new TrimModifier(50));
+        $this->assertEquals(35, $image->width());
+        $this->assertEquals(35, $image->height());
+    }
+
+    public function testTrimHighTolerance(): void
+    {
+        $image = $this->readTestImage('trim.png');
+        $this->assertEquals(50, $image->width());
+        $this->assertEquals(50, $image->height());
+        $image->modify(new TrimModifier(1000000));
+        $this->assertEquals(1, $image->width());
+        $this->assertEquals(1, $image->height());
+        $this->assertColor(255, 255, 255, 0, $image->pickColor(0, 0));
+    }
+
+    public function testTrimAnimated(): void
+    {
+        $image = $this->readTestImage('animation.gif');
+        $this->expectException(NotSupportedException::class);
+        $image->modify(new TrimModifier());
+    }
+}
diff --git a/tests/Unit/Drivers/Imagick/Modifiers/TrimModifierTest.php b/tests/Unit/Drivers/Imagick/Modifiers/TrimModifierTest.php
new file mode 100644
index 00000000..cd2bafdd
--- /dev/null
+++ b/tests/Unit/Drivers/Imagick/Modifiers/TrimModifierTest.php
@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests\Unit\Drivers\Imagick\Modifiers;
+
+use Intervention\Image\Exceptions\NotSupportedException;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\RequiresPhpExtension;
+use Intervention\Image\Modifiers\TrimModifier;
+use Intervention\Image\Tests\ImagickTestCase;
+
+#[RequiresPhpExtension('imagick')]
+#[CoversClass(\Intervention\Image\Modifiers\TrimModifier::class)]
+#[CoversClass(\Intervention\Image\Drivers\Imagick\Modifiers\TrimModifier::class)]
+final class TrimModifierTest extends ImagickTestCase
+{
+    public function testTrim(): void
+    {
+        $image = $this->readTestImage('trim.png');
+        $this->assertEquals(50, $image->width());
+        $this->assertEquals(50, $image->height());
+        $image->modify(new TrimModifier());
+        $this->assertEquals(28, $image->width());
+        $this->assertEquals(28, $image->height());
+    }
+
+    public function testTrimGradient(): void
+    {
+        $image = $this->readTestImage('radial.png');
+        $this->assertEquals(50, $image->width());
+        $this->assertEquals(50, $image->height());
+        $image->modify(new TrimModifier(50));
+        $this->assertEquals(29, $image->width());
+        $this->assertEquals(29, $image->height());
+    }
+
+    public function testTrimHighTolerance(): void
+    {
+        $image = $this->readTestImage('trim.png');
+        $this->assertEquals(50, $image->width());
+        $this->assertEquals(50, $image->height());
+        $image->modify(new TrimModifier(1000000));
+        $this->assertEquals(1, $image->width());
+        $this->assertEquals(1, $image->height());
+        $this->assertColor(255, 255, 255, 0, $image->pickColor(0, 0));
+    }
+
+    public function testTrimAnimated(): void
+    {
+        $image = $this->readTestImage('animation.gif');
+        $this->expectException(NotSupportedException::class);
+        $image->modify(new TrimModifier());
+    }
+}
diff --git a/tests/resources/radial.png b/tests/resources/radial.png
new file mode 100644
index 0000000000000000000000000000000000000000..788cbdfbe8af7a86e9873b7ba7f61e4f1ed0e8c6
GIT binary patch
literal 1254
zcmWlZdo<Ju0EK^~voj@WMy;f%jdDt3)KZDlcw~eaDO*zVSdNKg+9f4qsxfD_$YW<S
zDeIBQo61sYP)&K1iIDP4${0kRjl25eyWhFz+`n(E^FG@pi?kLI1hK@9Y3(v^;~$U~
z%%?$jSj@bXI4-u9N^O$Ok@JNd%sj*)h{e<&C=u61n)8D$X9rgs0CRItDDeF|W@j-o
zgXw8ZO<`gJ<Kq|`!`H7E9mVi4hK3-MVQ>&%zTop`jErDl03Sc1uMa&v=<Y^W7bYjs
z*@^e>@$Mbk+R)mHw{P+78(LZ*mE!elG&Z840rmB$t3!W3-n_x9SCB~X>=|lmP+bkN
z7;-sYyuj0^c>EX@6(}#q{rk9g552v3`4Y9YsH#Fq2?`65mxtV3<m8~E1I^8N{v4H+
zC@R9;yU5N)Mh4Q-aPuZoQ&C)utSsER1(66sA(E1ikbwAjJbHwJ0;HrME)D_#csyLX
z1TGhunMh8?)vJh&MN|~dox_<k2n$1KC=wHK{yaDwoIHsWC%|SSAOL(mqN5QW4nIG5
zd&AQcM~}k81OEOvejM)ZaC3vJD_mT_Vj(C9zP@m90F#M5dthUOBS*ksz}y^WX4ttC
z_V%!{!meE~HO1DgFfsy-217#_7(ibidV1Kr8M?Yyy&BruShEJ2npnOZR4OPGsHs6!
z6(kZCE(Ae9y=yO%Ae3*~Su<S2L^oO@oV4hgMDWaq1@a542C}OE(OaxPJE!9t>m&Ks
z_`QaSWOZ=FaCqead3(u(d?`i#_w9)G+lKzKK;2zSbW$H;Xd5Z#pyKNRPQfyw+vHRO
zVhAp=+cPj({BGnhC=8O=`WM#?E!UcMuqP?J@ck;}s0aH5W9@AXt^au_k4iMXwAba4
zM%Z3?^!!lo4iko^*Z7=L`ijCS13u$?Q2i4pwy3C)EcOq+NDdf0ouc9Md)f5%Qg(@c
z+^r`AW29ayVts~_^^ShUL%QOmBCS~-%eA<1_0`Y8ic?LSia*&kNKZ|Ec@tTtSX`mq
z$d6k}HD*@v=wYSya#3Q$F||J?FMm)!o#?&yr}S~@z_!bG@<Rn0TPoy{v>B^Rhd=$?
zRMZ7dA(m6qyc-skN>y==*M6OtYkX2BJ4VVYS>;`Nj3OYXC8j#k*~Qh$Wd{x1^-csy
z&z8q!aqc8GwF~(KpOk*ckJ0#B^c9``6T(9Glo$5RqW--Bx#x6wrMr0{t$kWLB`enr
z&Bz){17EsZ)$~|ck8%PRtQ8t1k7jk(=gSR0L{n&P{UMImYY=cn;<I+dvd<+Togu6>
zq9lieRZ)XFbG8_eJJfGe&C?#oZ>)`>UQ|sdtHi5wSq(e2eN{73eZF1!sHJhV|DZ#r
zvoV*fLbDSmtoS69nq)ZIo3b<xZ#3O6Cedj&<@y<Ww)d(gs2DHZ)Dv|&)5L|z+TfYu
zEH+w~yRlvCPP1CtS!Q-ApWEJU>zPzwuA)3Vv8-%u_aJ{gEk4AKn;j26g`Uh4*woqA
z$!zZy@shMzH2Q&+tl4E|4s{kQirk;dBy_XLnrRA$Un@$YZwRR?@8mu3*ybfS`iqy+
g6yQ+M@oY|6npu~tR^Q5)|0=@HW}kJwrRRnJ0o${>OaK4?

literal 0
HcmV?d00001