dekstop: image compression (#2979)

* dekstop: image compression

* refactor

apps/multiplatform/common/src/androidMain/kotlin/chat/simplex/common/platform/Images.android.kt

@@ -62,7 +62,7 @@ actual fun cropToSquare(image: ImageBitmap): ImageBitmap {
 }
 
 actual fun compressImageStr(bitmap: ImageBitmap): String {
-  val usePng = bitmap.hasAlpha
+  val usePng = bitmap.hasAlpha()
   val ext = if (usePng) "png" else "jpg"
   return "data:image/$ext;base64," + Base64.encodeToString(compressImageData(bitmap, usePng).toByteArray(), Base64.NO_WRAP)
 }
@@ -89,6 +89,8 @@ actual fun resizeImageToDataSize(image: ImageBitmap, usePng: Boolean, maxDataSiz
 
 actual fun GrayU8.toImageBitmap(): ImageBitmap = ConvertBitmap.grayToBitmap(this, Bitmap.Config.RGB_565).asImageBitmap()
 
+actual fun ImageBitmap.hasAlpha(): Boolean = hasAlpha
+
 actual fun ImageBitmap.addLogo(): ImageBitmap = asAndroidBitmap().applyCanvas {
   val radius = (width * 0.16f) / 2
   val paint = android.graphics.Paint()

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/platform/Images.kt

@@ -15,6 +15,7 @@ expect fun compressImageData(bitmap: ImageBitmap, usePng: Boolean): ByteArrayOut
 
 expect fun GrayU8.toImageBitmap(): ImageBitmap
 
+expect fun ImageBitmap.hasAlpha(): Boolean
 expect fun ImageBitmap.addLogo(): ImageBitmap
 expect fun ImageBitmap.scale(width: Int, height: Int): ImageBitmap
 

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/helpers/Utils.kt

@@ -102,7 +102,7 @@ fun saveImage(uri: URI): String? {
 
 fun saveImage(image: ImageBitmap): String? {
   return try {
-    val ext = if (image.hasAlpha) "png" else "jpg"
+    val ext = if (image.hasAlpha()) "png" else "jpg"
     val dataResized = resizeImageToDataSize(image, ext == "png", maxDataSize = MAX_IMAGE_SIZE)
     val fileToSave = generateNewFileName("IMG", ext)
     val file = File(getAppFilePath(fileToSave))
@@ -112,7 +112,7 @@ fun saveImage(image: ImageBitmap): String? {
     output.close()
     fileToSave
   } catch (e: Exception) {
-    Log.e(TAG, "Util.kt saveImage error: ${e.message}")
+    Log.e(TAG, "Util.kt saveImage error: ${e.stackTraceToString()}")
     null
   }
 }

apps/multiplatform/common/src/desktopMain/kotlin/chat/simplex/common/platform/Images.desktop.kt

@@ -10,7 +10,8 @@ import java.awt.image.BufferedImage
 import java.io.*
 import java.net.URI
 import java.util.*
-import javax.imageio.ImageIO
+import javax.imageio.*
+import javax.imageio.stream.MemoryCacheImageOutputStream
 import kotlin.math.sqrt
 
 private fun errorBitmap(): ImageBitmap =
@@ -69,7 +70,7 @@ actual fun cropToSquare(image: ImageBitmap): ImageBitmap {
 }
 
 actual fun compressImageStr(bitmap: ImageBitmap): String {
-  val usePng = bitmap.hasAlpha
+  val usePng = bitmap.hasAlpha()
   val ext = if (usePng) "png" else "jpg"
   return try {
     val encoded  = Base64.getEncoder().encodeToString(compressImageData(bitmap, usePng).toByteArray())
@@ -81,15 +82,45 @@ actual fun compressImageStr(bitmap: ImageBitmap): String {
 }
 
 actual fun compressImageData(bitmap: ImageBitmap, usePng: Boolean): ByteArrayOutputStream {
+  val writer = ImageIO.getImageWritersByFormatName(if (usePng) "png" else "jpg").next()
+  val writeParam = writer.defaultWriteParam
+  writeParam.compressionMode = ImageWriteParam.MODE_EXPLICIT
+  writeParam.compressionQuality = 0.85f
   val stream = ByteArrayOutputStream()
-  stream.use { s -> ImageIO.write(bitmap.toAwtImage(), if (usePng) "png" else "jpg", s) }
-  // MAKE REAL COMPRESSION
-  //bitmap.compress(if (!usePng) Bitmap.CompressFormat.JPEG else Bitmap.CompressFormat.PNG, 85, stream)
+  writer.output = MemoryCacheImageOutputStream(stream)
+  val outputImage = IIOImage(if (usePng) bitmap.toAwtImage() else removeAlphaChannel(bitmap.toAwtImage()), null, null)
+  writer.write(null, outputImage, writeParam)
+  writer.dispose()
+  stream.flush()
   return stream
 }
 
+private fun removeAlphaChannel(img: BufferedImage): BufferedImage {
+  if (!img.colorModel.hasAlpha()) return img
+  val target = BufferedImage(img.width, img.height, BufferedImage.TYPE_INT_RGB)
+  val g = target.createGraphics()
+  g.fillRect(0, 0, img.width, img.height)
+  g.drawImage(img, 0, 0, null)
+  g.dispose()
+  return target
+}
+
 actual fun GrayU8.toImageBitmap(): ImageBitmap = ConvertBufferedImage.extractBuffered(this).toComposeImageBitmap()
 
+actual fun ImageBitmap.hasAlpha(): Boolean {
+  val map = toPixelMap()
+  var y = 0
+  while (y < height) {
+    var x = 0
+    while (x < width) {
+      if (map[x, y].alpha < 1f) return true
+      x++
+    }
+    y++
+  }
+  return false
+}
+
 actual fun ImageBitmap.addLogo(): ImageBitmap {
   val radius = (width * 0.16f).toInt()
   val logoSize = (width * 0.24).toInt()