src/main/kotlin/kr/co/vividnext/sodalive/admin/chat/character/image/AdminCharacterImageController.kt

@@ -35,7 +35,10 @@ class AdminCharacterImageController(
     private val imageCloudFront: ImageContentCloudFront,
 
     @Value("\${cloud.aws.s3.content-bucket}")
-    private val s3Bucket: String
+    private val s3Bucket: String,
+
+    @Value("\${cloud.aws.s3.bucket}")
+    private val freeBucket: String
 ) {
 
     @GetMapping("/list")
@@ -65,13 +68,19 @@ class AdminCharacterImageController(
         val objectMapper = ObjectMapper()
         val request = objectMapper.readValue(requestString, RegisterCharacterImageRequest::class.java)
 
-        // 1) 임시 경로로 엔티티 생성하기 전에 파일 업로드 경로 계산
-        val tempKey = buildS3Key(characterId = request.characterId)
-        val imagePath = saveImage(tempKey, image)
+        // 업로드 키 생성
+        val s3Key = buildS3Key(characterId = request.characterId)
+
+        // 원본 저장 (content-bucket)
+        val imagePath = saveImageToBucket(s3Key, image, s3Bucket)
+
+        // 블러 생성 및 저장 (무료 이미지 버킷)
+        val blurImagePath = saveBlurImageToBucket(s3Key, image, freeBucket)
 
         imageService.registerImage(
             characterId = request.characterId,
             imagePath = imagePath,
+            blurImagePath = blurImagePath,
             price = request.price,
             isAdult = request.isAdult,
             triggers = request.triggers ?: emptyList()
@@ -108,13 +117,13 @@ class AdminCharacterImageController(
         return "characters/$characterId/images/$fileName"
     }
 
-    private fun saveImage(filePath: String, image: MultipartFile): String {
+    private fun saveImageToBucket(filePath: String, image: MultipartFile, bucket: String): String {
         try {
             val metadata = ObjectMetadata()
             metadata.contentLength = image.size
             return s3Uploader.upload(
                 inputStream = image.inputStream,
-                bucket = s3Bucket,
+                bucket = bucket,
                 filePath = filePath,
                 metadata = metadata
             )
@@ -122,4 +131,36 @@ class AdminCharacterImageController(
             throw SodaException("이미지 저장에 실패했습니다: ${e.message}")
         }
     }
+
+    private fun saveBlurImageToBucket(filePath: String, image: MultipartFile, bucket: String): String {
+        try {
+            // 멀티파트를 BufferedImage로 읽기
+            val bytes = image.bytes
+            val bimg = javax.imageio.ImageIO.read(java.io.ByteArrayInputStream(bytes))
+                ?: throw SodaException("이미지 포맷을 인식할 수 없습니다.")
+            val blurred = kr.co.vividnext.sodalive.utils.ImageBlurUtil.blur(bimg, 12)
+
+            // PNG로 저장(알파 유지), JPEG 업로드가 필요하면 포맷 변경 가능
+            val baos = java.io.ByteArrayOutputStream()
+            val format = when (image.contentType?.lowercase()) {
+                "image/png" -> "png"
+                else -> "jpg"
+            }
+            javax.imageio.ImageIO.write(blurred, format, baos)
+            val inputStream = java.io.ByteArrayInputStream(baos.toByteArray())
+
+            val metadata = ObjectMetadata()
+            metadata.contentLength = baos.size().toLong()
+            metadata.contentType = image.contentType ?: if (format == "png") "image/png" else "image/jpeg"
+
+            return s3Uploader.upload(
+                inputStream = inputStream,
+                bucket = bucket,
+                filePath = filePath,
+                metadata = metadata
+            )
+        } catch (e: Exception) {
+            throw SodaException("블러 이미지 저장에 실패했습니다: ${e.message}")
+        }
+    }
 }

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/image/CharacterImage.kt

@@ -15,9 +15,12 @@ class CharacterImage(
     @JoinColumn(name = "character_id")
     var chatCharacter: ChatCharacter,
 
-    // 이미지 경로 (S3 key)
+    // 원본 이미지 경로 (S3 key - content-bucket)
     var imagePath: String,
 
+    // 블러 이미지 경로 (S3 key - free/public bucket)
+    var blurImagePath: String,
+
     // 가격 (메시지/이미지 통합 단일가 - 요구사항 범위)
     var price: Long = 0L,
 

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/image/CharacterImageService.kt

@@ -23,6 +23,7 @@ class CharacterImageService(
     fun registerImage(
         characterId: Long,
         imagePath: String,
+        blurImagePath: String,
         price: Long,
         isAdult: Boolean,
         triggers: List<String>
@@ -36,6 +37,7 @@ class CharacterImageService(
         val entity = CharacterImage(
             chatCharacter = character,
             imagePath = imagePath,
+            blurImagePath = blurImagePath,
             price = price,
             isAdult = isAdult,
             sortOrder = nextOrder,

src/main/kotlin/kr/co/vividnext/sodalive/utils/ImageBlurUtil.kt

@@ -0,0 +1,102 @@
+package kr.co.vividnext.sodalive.utils
+
+import java.awt.image.BufferedImage
+import kotlin.math.exp
+import kotlin.math.max
+import kotlin.math.min
+
+/**
+ * 가우시안 커널 기반 블러 유틸리티
+ * - 반경(radius)에 따라 커널 크기(2*radius+1) 생성
+ * - 시그마는 관례적으로 radius/3.0 적용
+ * - 수평/수직 분리 합성곱으로 품질과 성능 확보
+ */
+object ImageBlurUtil {
+    fun blur(src: BufferedImage, radius: Int = 10): BufferedImage {
+        require(radius > 0) { "radius must be > 0" }
+        val w = src.width
+        val h = src.height
+        val dst = BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB)
+
+        // 가우시안 1D 커널 생성 및 정규화
+        val sigma = radius / 3.0
+        val kernel = gaussianKernel(radius, sigma)
+
+        // 중간 버퍼
+        val temp = BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB)
+
+        // 수평 합성곱
+        for (y in 0 until h) {
+            for (x in 0 until w) {
+                var aAcc = 0.0
+                var rAcc = 0.0
+                var gAcc = 0.0
+                var bAcc = 0.0
+                for (k in -radius..radius) {
+                    val xx = clamp(x + k, 0, w - 1)
+                    val rgb = src.getRGB(xx, y)
+                    val a = (rgb ushr 24) and 0xFF
+                    val r = (rgb ushr 16) and 0xFF
+                    val g = (rgb ushr 8) and 0xFF
+                    val b = rgb and 0xFF
+                    val wgt = kernel[k + radius]
+                    aAcc += a * wgt
+                    rAcc += r * wgt
+                    gAcc += g * wgt
+                    bAcc += b * wgt
+                }
+                val a = aAcc.toInt().coerceIn(0, 255)
+                val r = rAcc.toInt().coerceIn(0, 255)
+                val g = gAcc.toInt().coerceIn(0, 255)
+                val b = bAcc.toInt().coerceIn(0, 255)
+                temp.setRGB(x, y, (a shl 24) or (r shl 16) or (g shl 8) or b)
+            }
+        }
+
+        // 수직 합성곱
+        for (x in 0 until w) {
+            for (y in 0 until h) {
+                var aAcc = 0.0
+                var rAcc = 0.0
+                var gAcc = 0.0
+                var bAcc = 0.0
+                for (k in -radius..radius) {
+                    val yy = clamp(y + k, 0, h - 1)
+                    val rgb = temp.getRGB(x, yy)
+                    val a = (rgb ushr 24) and 0xFF
+                    val r = (rgb ushr 16) and 0xFF
+                    val g = (rgb ushr 8) and 0xFF
+                    val b = rgb and 0xFF
+                    val wgt = kernel[k + radius]
+                    aAcc += a * wgt
+                    rAcc += r * wgt
+                    gAcc += g * wgt
+                    bAcc += b * wgt
+                }
+                val a = aAcc.toInt().coerceIn(0, 255)
+                val r = rAcc.toInt().coerceIn(0, 255)
+                val g = gAcc.toInt().coerceIn(0, 255)
+                val b = bAcc.toInt().coerceIn(0, 255)
+                dst.setRGB(x, y, (a shl 24) or (r shl 16) or (g shl 8) or b)
+            }
+        }
+        return dst
+    }
+
+    private fun gaussianKernel(radius: Int, sigma: Double): DoubleArray {
+        val size = 2 * radius + 1
+        val kernel = DoubleArray(size)
+        val sigma2 = 2.0 * sigma * sigma
+        var sum = 0.0
+        for (i in -radius..radius) {
+            val v = exp(-(i * i) / sigma2)
+            kernel[i + radius] = v
+            sum += v
+        }
+        // 정규화
+        for (i in kernel.indices) kernel[i] /= sum
+        return kernel
+    }
+
+    private fun clamp(v: Int, lo: Int, hi: Int): Int = max(lo, min(hi, v))
+}