diff --git a/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCode.kt b/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCode.kt
index a7725e6..0873626 100644
--- a/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCode.kt
+++ b/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCode.kt
@@ -4,10 +4,33 @@ import com.soywiz.korim.bitmap.Bitmap32
 
 
 open class EpcQrCode(
-  open val bitmap: Bitmap32
+  bitmap: Bitmap32,
+  heightAndWidth: Int = DefaultHeightAndWidth
 ) {
 
+  companion object {
+
+    const val DefaultHeightAndWidth = 500
+
+  }
+
+
+  open var bitmap: Bitmap32 = bitmap // declare before init() method, otherwise application will crash
+    protected set
+
   open val bytes: ByteArray
     get() = bitmap.extractBytes()
 
+
+  constructor(bitmap: Bitmap32) : this(bitmap, DefaultHeightAndWidth) // convenience constructor for languages that don't support default parameters
+
+  init {
+    scale(heightAndWidth)
+  }
+
+
+  open fun scale(heightAndWidth: Int) {
+    this.bitmap = bitmap.scaled(heightAndWidth, heightAndWidth, true)
+  }
+
 }
\ No newline at end of file
diff --git a/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCodeGenerator.kt b/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCodeGenerator.kt
index 50282ee..65b344a 100644
--- a/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCodeGenerator.kt
+++ b/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCodeGenerator.kt
@@ -7,12 +7,16 @@ import com.soywiz.korim.qr.QRErrorCorrectLevel
 open class EpcQrCodeGenerator {
 
 
-    open fun generateEpcQrCode(param: EpcQrCodeConfig): EpcQrCode {
+    open fun generateEpcQrCode(config: EpcQrCodeConfig): EpcQrCode {
+        return generateEpcQrCode(config, EpcQrCode.DefaultHeightAndWidth)
+    }
+
+    open fun generateEpcQrCode(config: EpcQrCodeConfig, heightAndWidth: Int = EpcQrCode.DefaultHeightAndWidth): EpcQrCode {
         val qrCode = QR(correctLevel = QRErrorCorrectLevel.M)
 
-        val qrCodeBitmap = qrCode.msg(generateAsString(param))
+        val qrCodeBitmap = qrCode.msg(generateAsString(config))
 
-        return EpcQrCode(qrCodeBitmap)
+        return EpcQrCode(qrCodeBitmap, heightAndWidth)
     }
 
     open fun generate(param: EpcQrCodeConfig): EpcQrCodeValues {
diff --git a/EpcQrCodeAndroidApp/src/main/java/net/codinux/banking/epcqrcode/MainActivity.kt b/EpcQrCodeAndroidApp/src/main/java/net/codinux/banking/epcqrcode/MainActivity.kt
index b0f4038..0d1d492 100644
--- a/EpcQrCodeAndroidApp/src/main/java/net/codinux/banking/epcqrcode/MainActivity.kt
+++ b/EpcQrCodeAndroidApp/src/main/java/net/codinux/banking/epcqrcode/MainActivity.kt
@@ -42,9 +42,9 @@ class MainActivity : AppCompatActivity() {
     private fun generateQrCodeAsync(param: EpcQrCodeConfig, done: (Bitmap) -> Unit) {
         GlobalScope.launch(Dispatchers.IO) {
             val density = resources.displayMetrics.density
-            val config = EncodeToQrCodeConfig((EncodeToQrCodeConfig.DefaultWidth * density).toInt(), (EncodeToQrCodeConfig.DefaultHeight * density).toInt())
+            val heightAndWidth = (350 * density).toInt()
 
-            val epcQrCode = EpcQrCodeGenerator().generateEpcQrCode(param)
+            val epcQrCode = EpcQrCodeGenerator().generateEpcQrCode(param, heightAndWidth)
 
             withContext(Dispatchers.Main) {
                 done(epcQrCode.androidBitmap)
diff --git a/EpcQrCodeRest/src/main/kotlin/net/codinux/banking/epcqrcode/rest/EpcQrCodeResource.kt b/EpcQrCodeRest/src/main/kotlin/net/codinux/banking/epcqrcode/rest/EpcQrCodeResource.kt
index 9cb000f..d9737fb 100644
--- a/EpcQrCodeRest/src/main/kotlin/net/codinux/banking/epcqrcode/rest/EpcQrCodeResource.kt
+++ b/EpcQrCodeRest/src/main/kotlin/net/codinux/banking/epcqrcode/rest/EpcQrCodeResource.kt
@@ -1,9 +1,7 @@
 package net.codinux.banking.epcqrcode.rest
 
 import net.codinux.banking.epcqrcode.EpcQrCodeConfig
-import net.codinux.banking.epcqrcode.EncodeToQrCodeConfig
 import net.codinux.banking.epcqrcode.EpcQrCodeGenerator
-import net.codinux.banking.epcqrcode.QrCodeGenerator
 import net.codinux.banking.epcqrcode.rest.dto.GenerateEpcQrCodeRequestDto
 import net.codinux.banking.epcqrcode.rest.dto.GenerateEpcQrCodeResponseDto
 import org.slf4j.LoggerFactory
@@ -24,15 +22,13 @@ class EpcQrCodeResource {
 
     protected val epcQrCodeGenerator = EpcQrCodeGenerator()
 
-    protected val qrCodeGenerator = QrCodeGenerator()
-
 
     @POST
     @Produces(MediaType.APPLICATION_JSON)
     fun createEpcQrCode(requestDto: GenerateEpcQrCodeRequestDto): Response {
         try {
-            val qrCodeContent = epcQrCodeGenerator.generateAsString(mapToEpcQrCodeConfig(requestDto))
-            val qrCodeBytes = qrCodeGenerator.generateQrCode(qrCodeContent, map(requestDto))
+            val epcQrCode = epcQrCodeGenerator.generateEpcQrCode(mapToEpcQrCodeConfig(requestDto), requestDto.imageHeightAndWidth)
+            val qrCodeBytes = epcQrCode.bytes // TODO: convert to Base64
 
             return Response.ok(GenerateEpcQrCodeResponseDto(qrCodeBytes))
                 .header("Access-Control-Allow-Origin", "*")
@@ -40,7 +36,7 @@ class EpcQrCodeResource {
         } catch (e: Exception) {
             log.error("Could not create QR code for $requestDto", e)
 
-            return Response.serverError()
+            return Response.status(Response.Status.INTERNAL_SERVER_ERROR.statusCode, e.localizedMessage) // TODO: it's almost always a bad idea to pass exception message to the outside
                 .header("Access-Control-Allow-Origin", "*")
                 .build()
         }
@@ -57,13 +53,4 @@ class EpcQrCodeResource {
         )
     }
 
-    private fun map(dto: GenerateEpcQrCodeRequestDto): EncodeToQrCodeConfig {
-        return EncodeToQrCodeConfig(
-            dto.imageWidth,
-            dto.imageHeight,
-            dto.imageFormat,
-            dto.encoding
-        )
-    }
-
 }
\ No newline at end of file
diff --git a/EpcQrCodeRest/src/main/kotlin/net/codinux/banking/epcqrcode/rest/dto/GenerateEpcQrCodeRequestDto.kt b/EpcQrCodeRest/src/main/kotlin/net/codinux/banking/epcqrcode/rest/dto/GenerateEpcQrCodeRequestDto.kt
index 14f264d..819a42f 100644
--- a/EpcQrCodeRest/src/main/kotlin/net/codinux/banking/epcqrcode/rest/dto/GenerateEpcQrCodeRequestDto.kt
+++ b/EpcQrCodeRest/src/main/kotlin/net/codinux/banking/epcqrcode/rest/dto/GenerateEpcQrCodeRequestDto.kt
@@ -1,5 +1,6 @@
 package net.codinux.banking.epcqrcode.rest.dto
 
+import net.codinux.banking.epcqrcode.EpcQrCode
 import net.codinux.banking.epcqrcode.EpcQrCodeCharacterSet
 import net.codinux.banking.epcqrcode.ImageFormat
 
@@ -18,9 +19,7 @@ class GenerateEpcQrCodeRequestDto {
 
     var noteToUser: String? = null
 
-    var imageWidth: Int = 500
-
-    var imageHeight: Int = 500
+    var imageHeightAndWidth: Int = EpcQrCode.DefaultHeightAndWidth
 
     var imageFormat: ImageFormat = ImageFormat.PNG