diff --git a/app/code/Magento/Catalog/Model/ResourceModel/Product/Image.php b/app/code/Magento/Catalog/Model/ResourceModel/Product/Image.php
index 123f358be40c8..77f67480619e0 100644
--- a/app/code/Magento/Catalog/Model/ResourceModel/Product/Image.php
+++ b/app/code/Magento/Catalog/Model/ResourceModel/Product/Image.php
@@ -12,6 +12,9 @@
 use Magento\Framework\DB\Select;
 use Magento\Framework\App\ResourceConnection;
 
+/**
+ * Class for retrieval of all product images
+ */
 class Image
 {
     /**
@@ -73,15 +76,24 @@ public function getAllProductImages(): \Generator
 
     /**
      * Get the number of unique pictures of products
+     *
      * @return int
      */
     public function getCountAllProductImages(): int
     {
-        $select = $this->getVisibleImagesSelect()->reset('columns')->columns('count(*)');
+        $select = $this->getVisibleImagesSelect()
+            ->reset('columns')
+            ->reset('distinct')
+            ->columns(
+                new \Zend_Db_Expr('count(distinct value)')
+            );
+
         return (int) $this->connection->fetchOne($select);
     }
 
     /**
+     * Return Select to fetch all products images
+     *
      * @return Select
      */
     private function getVisibleImagesSelect(): Select
diff --git a/app/code/Magento/Catalog/Test/Unit/Model/ResourceModel/Product/ImageTest.php b/app/code/Magento/Catalog/Test/Unit/Model/ResourceModel/Product/ImageTest.php
new file mode 100644
index 0000000000000..4fce12dc2de89
--- /dev/null
+++ b/app/code/Magento/Catalog/Test/Unit/Model/ResourceModel/Product/ImageTest.php
@@ -0,0 +1,237 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Catalog\Test\Unit\Model\ResourceModel\Product;
+
+use Magento\Catalog\Model\ResourceModel\Product\Image;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\DB\Query\Generator;
+use Magento\Framework\DB\Select;
+use Magento\Framework\App\ResourceConnection;
+use Magento\Catalog\Model\ResourceModel\Product\Gallery;
+use PHPUnit_Framework_MockObject_MockObject as MockObject;
+use Magento\Framework\DB\Query\BatchIteratorInterface;
+
+class ImageTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var \Magento\Framework\TestFramework\Unit\Helper\ObjectManager
+     */
+    protected $objectManager;
+
+    /**
+     * @var AdapterInterface | MockObject
+     */
+    protected $connectionMock;
+
+    /**
+     * @var Generator | MockObject
+     */
+    protected $generatorMock;
+
+    /**
+     * @var ResourceConnection | MockObject
+     */
+    protected $resourceMock;
+
+    protected function setUp(): void
+    {
+        $this->objectManager =
+            new \Magento\Framework\TestFramework\Unit\Helper\ObjectManager($this);
+        $this->connectionMock = $this->createMock(AdapterInterface::class);
+        $this->resourceMock = $this->createMock(ResourceConnection::class);
+        $this->resourceMock->method('getConnection')
+            ->willReturn($this->connectionMock);
+        $this->resourceMock->method('getTableName')
+            ->willReturnArgument(0);
+        $this->generatorMock = $this->createMock(Generator::class);
+    }
+
+    /**
+     * @return MockObject
+     */
+    protected function getVisibleImagesSelectMock(): MockObject
+    {
+        $selectMock = $this->getMockBuilder(Select::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $selectMock->expects($this->once())
+            ->method('distinct')
+            ->willReturnSelf();
+        $selectMock->expects($this->once())
+            ->method('from')
+            ->with(
+                ['images' => Gallery::GALLERY_TABLE],
+                'value as filepath'
+            )->willReturnSelf();
+        $selectMock->expects($this->once())
+            ->method('where')
+            ->with('disabled = 0')
+            ->willReturnSelf();
+
+        return $selectMock;
+    }
+
+    /**
+     * @param int $imagesCount
+     * @dataProvider dataProvider
+     */
+    public function testGetCountAllProductImages(int $imagesCount): void
+    {
+        $selectMock = $this->getVisibleImagesSelectMock();
+        $selectMock->expects($this->exactly(2))
+            ->method('reset')
+            ->withConsecutive(
+                ['columns'],
+                ['distinct']
+            )->willReturnSelf();
+        $selectMock->expects($this->once())
+            ->method('columns')
+            ->with(new \Zend_Db_Expr('count(distinct value)'))
+            ->willReturnSelf();
+
+        $this->connectionMock->expects($this->once())
+            ->method('select')
+            ->willReturn($selectMock);
+        $this->connectionMock->expects($this->once())
+            ->method('fetchOne')
+            ->with($selectMock)
+            ->willReturn($imagesCount);
+
+        $imageModel = $this->objectManager->getObject(
+            Image::class,
+            [
+                'generator' => $this->generatorMock,
+                'resourceConnection' => $this->resourceMock
+            ]
+        );
+
+        $this->assertSame(
+            $imagesCount,
+            $imageModel->getCountAllProductImages()
+        );
+    }
+
+    /**
+     * @param int $imagesCount
+     * @param int $batchSize
+     * @dataProvider dataProvider
+     */
+    public function testGetAllProductImages(
+        int $imagesCount,
+        int $batchSize
+    ): void {
+        $this->connectionMock->expects($this->once())
+            ->method('select')
+            ->willReturn($this->getVisibleImagesSelectMock());
+
+        $batchCount = (int)ceil($imagesCount / $batchSize);
+        $fetchResultsCallback = $this->getFetchResultCallbackForBatches($imagesCount, $batchSize);
+        $this->connectionMock->expects($this->exactly($batchCount))
+            ->method('fetchAll')
+            ->will($this->returnCallback($fetchResultsCallback));
+
+        /** @var Select | MockObject $selectMock */
+        $selectMock = $this->getMockBuilder(Select::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $this->generatorMock->expects($this->once())
+            ->method('generate')
+            ->with(
+                'value_id',
+                $selectMock,
+                $batchSize,
+                BatchIteratorInterface::NON_UNIQUE_FIELD_ITERATOR
+            )->will(
+                $this->returnCallback(
+                    $this->getBatchIteratorCallback($selectMock, $batchCount)
+                )
+            );
+
+        $imageModel = $this->objectManager->getObject(
+            Image::class,
+            [
+                'generator' => $this->generatorMock,
+                'resourceConnection' => $this->resourceMock,
+                'batchSize' => $batchSize
+            ]
+        );
+
+        $this->assertCount($imagesCount, $imageModel->getAllProductImages());
+    }
+
+    /**
+     * @param int $imagesCount
+     * @param int $batchSize
+     * @return \Closure
+     */
+    protected function getFetchResultCallbackForBatches(
+        int $imagesCount,
+        int $batchSize
+    ): \Closure {
+        $fetchResultsCallback = function () use (&$imagesCount, $batchSize) {
+            $batchSize =
+                ($imagesCount >= $batchSize) ? $batchSize : $imagesCount;
+            $imagesCount -= $batchSize;
+
+            $getFetchResults = function ($batchSize): array {
+                $result = [];
+                $count = $batchSize;
+                while ($count) {
+                    $count--;
+                    $result[$count] = $count;
+                }
+
+                return $result;
+            };
+
+            return $getFetchResults($batchSize);
+        };
+
+        return $fetchResultsCallback;
+    }
+
+    /**
+     * @param Select | MockObject $selectMock
+     * @param int $batchCount
+     * @return \Closure
+     */
+    protected function getBatchIteratorCallback(
+        MockObject $selectMock,
+        int $batchCount
+    ): \Closure {
+        $iteratorCallback = function () use ($batchCount, $selectMock): array {
+            $result = [];
+            $count = $batchCount;
+            while ($count) {
+                $count--;
+                $result[$count] = $selectMock;
+            }
+
+            return $result;
+        };
+
+        return $iteratorCallback;
+    }
+
+    /**
+     * Data Provider
+     * @return array
+     */
+    public function dataProvider(): array
+    {
+        return [
+            [300, 300],
+            [300, 100],
+            [139, 100],
+            [67, 10],
+            [154, 47],
+            [0, 100]
+        ];
+    }
+}