Use libvips

Author: StefanOltmann

.run/HTTP test.run.xml

@@ -0,0 +1,5 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="HTTP test" type="HttpClient.HttpRequestRunConfigurationType" factoryName="HTTP Request" path="$PROJECT_DIR$/Test.http" requestIdentifier="GET request to example server" runType="Run single request">
+    <method v="2" />
+  </configuration>
+</component>

Dockerfile

@@ -7,6 +7,7 @@ COPY src src
 RUN ./gradlew --no-daemon --info buildFatJar
 
 FROM amazoncorretto:22-alpine
+RUN apk add --no-cache vips-dev
 RUN mkdir /app
 COPY --from=BUILD_STAGE /tmp/build/libs/*-all.jar /app/ktor-server.jar
 EXPOSE 8080:8080

README.md

@@ -1 +1,21 @@
 # Ashampoo Image Proxy Service
+
+## Installation
+
+WiP
+
+## Contributions
+
+Contributions are welcome! If you encounter any issues,
+have suggestions for improvements, or would like to contribute new features,
+please feel free to submit a pull request.
+
+## Acknowledgements
+
+* JetBrains for making [Kotlin](https://kotlinlang.org).
+* John Cupitt for making [libvips](https://github.com/libvips/).
+* carrot for making [vips-ffm](https://github.com/lopcode/vips-ffm).
+
+## License
+
+This code is under the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0).

Test.http

@@ -0,0 +1,5 @@
+GET http://0.0.0.0:8080/
+RemoteUrl: https://raw.githubusercontent.com/Ashampoo/imageproxy/refs/heads/main/src/main/resources/sample.jpg
+LongSidePx: 320
+Quality: 80
+

build.gradle.kts

@@ -1,7 +1,6 @@
 val kotlin_version: String by project
 val logback_version: String by project
 val vips_ffm_version: String by project
-val skiko_version: String by project
 
 plugins {
     kotlin("jvm") version "2.1.0"
@@ -44,28 +43,4 @@ dependencies {
     implementation("app.photofox.vips-ffm:vips-ffm-core:$vips_ffm_version")
 
     implementation("ch.qos.logback:logback-classic:$logback_version")
-
-    /*
-     * SKIKO
-     */
-
-    val osName = System.getProperty("os.name")
-    val targetOs = when {
-        osName == "Mac OS X" -> "macos"
-        osName.startsWith("Win") -> "windows"
-        osName.startsWith("Linux") -> "linux"
-        else -> error("Unsupported OS: $osName")
-    }
-
-    val osArch = System.getProperty("os.arch")
-    val targetArch = when (osArch) {
-        "x86_64", "amd64" -> "x64"
-        "aarch64" -> "arm64"
-        else -> error("Unsupported arch: $osArch")
-    }
-
-    val target = "${targetOs}-${targetArch}"
-    dependencies {
-        implementation("org.jetbrains.skiko:skiko-awt-runtime-$target:$skiko_version")
-    }
 }

gradle.properties

@@ -3,4 +3,3 @@ kotlin_version=2.1.0
 ktor_version=3.0.2
 logback_version=1.4.14
 vips_ffm_version=1.3.0
-skiko_version=0.8.18

src/main/kotlin/com/ashampoo/imageproxy/Application.kt

@@ -15,11 +15,16 @@
  */
 package com.ashampoo.imageproxy
 
+import app.photofox.vipsffm.Vips
 import io.ktor.server.application.*
 import io.ktor.server.engine.*
 import io.ktor.server.netty.*
 
 fun main() {
+
+    /* Initialize LibVips */
+    Vips.init()
+
     embeddedServer(
         factory = Netty,
         port = 8080,

src/main/kotlin/com/ashampoo/imageproxy/Routing.kt

@@ -15,6 +15,10 @@
  */
 package com.ashampoo.imageproxy
 
+import app.photofox.vipsffm.VImage
+import app.photofox.vipsffm.Vips
+import app.photofox.vipsffm.VipsError
+import app.photofox.vipsffm.VipsOption
 import io.ktor.client.*
 import io.ktor.client.request.*
 import io.ktor.client.statement.*
@@ -23,8 +27,12 @@ import io.ktor.server.application.*
 import io.ktor.server.request.*
 import io.ktor.server.response.*
 import io.ktor.server.routing.*
-import org.jetbrains.skia.Image
-import org.slf4j.LoggerFactory
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.ByteArrayOutputStream
+import kotlin.math.max
+import kotlin.math.round
 
 private const val SERVER_BANNER = "Ashampoo Image Proxy Service"
 private const val AUTHORIZATION_HEADER = "Authorization"
@@ -34,8 +42,13 @@ private val validQualityRange = 10..100
 private const val DEFAULT_LONG_SIDE_PX = 480
 private const val DEFAULT_QUALITY = 90
 
+private const val DEFAULT_TARGET_FORMAT = ".jpg"
+
 private val httpClient = HttpClient()
 
+private val noRotate = VipsOption.Enum("no_rotate", 1)
+private val stripMetadata = VipsOption.Enum("strip", 1)
+
 private val usageString = buildString {
 
     appendLine(SERVER_BANNER)
@@ -104,17 +117,77 @@ fun Application.configureRouting() {
 
             val remoteBytes = response.bodyAsBytes()
 
-            val image = Image.makeFromEncoded(remoteBytes)
+            try {
+
+                val thumbnailBytes = createThumbnailBytes(
+                    originalBytes = remoteBytes,
+                    longSidePx = longSidePx,
+                    quality = quality
+                )
+
+                call.respondBytes(
+                    bytes = thumbnailBytes,
+                    contentType = ContentType.Image.JPEG,
+                    status = HttpStatusCode.OK
+                )
+
+            } catch (ex: VipsError) {
+
+                log.error("Error in image processing.", ex)
+
+                call.respond(HttpStatusCode.InternalServerError, ex.message ?: "Error")
+
+                return@get
+            }
+        }
+    }
+}
+
+private suspend fun createThumbnailBytes(
+    originalBytes: ByteArray,
+    longSidePx: Int,
+    quality: Int
+): ByteArray {
+
+    val deferred = CompletableDeferred<ByteArray>()
+
+    withContext(Dispatchers.IO) {
+
+        try {
 
-            val thumbnail = image.scale(longSidePx)
+            Vips.run { arena ->
 
-            val thumbnailBytes = thumbnail.encodeToJpg(quality)
+                val sourceImage = VImage.newFromBytes(arena, originalBytes)
+
+                val resizeFactor: Double =
+                    longSidePx / max(sourceImage.width.toDouble(), sourceImage.height.toDouble())
+
+                @Suppress("MagicNumber")
+                val thumbnailWidth = max(1, round(resizeFactor * sourceImage.width + 0.3).toInt())
+
+                val thumbnail = sourceImage.thumbnailImage(
+                    thumbnailWidth,
+                    noRotate
+                )
 
-            call.respondBytes(
-                bytes = thumbnailBytes,
-                contentType = ContentType.Image.JPEG,
-                status = HttpStatusCode.OK
-            )
+                val outputStream = ByteArrayOutputStream()
+
+                thumbnail.writeToStream(
+                    outputStream,
+                    DEFAULT_TARGET_FORMAT,
+                    stripMetadata,
+                    VipsOption.Enum("Q", quality)
+                )
+
+                val thumbnailBytes = outputStream.toByteArray()
+
+                deferred.complete(thumbnailBytes)
+            }
+
+        } catch (ex: Exception) {
+            deferred.completeExceptionally(ex)
         }
     }
+
+    return deferred.await()
 }