在Scala中编写功能强大且功能强大的图像处理库

我们正在为Scala(学生项目)开发一个小型图像处理库。该库完全功能(即无变异性)。图像的栅格存储为Stream [Stream [Int]]，以最小的努力利用懒惰评估的好处。然而，在对映像执行一些操作时，堆将被满载并抛出OutOfMemoryError。 (例如，在JVM堆空间不足之前，可以对大小为500 x 400,35 kb的jpeg图像执行多达4个操作。)

我们想到的方法是：

>使用JVM选项进行Twiddling并增加堆大小。 (我们不知道如何做到这一点在IDEA – 我们正在使用的IDE。)
>选择与Stream [Stream [Int]]不同的数据结构，更适合图像处理任务。 (再次，我们对于简单的List和Stream之外的功能数据结构并不太了解。)

我们最后一个选择是放弃不变性，并使其成为一个可变的库(如流行的图像处理库)，这是我们不想做的。请建议我们有一些方法来保持这个库的功能并且仍然有效，如果你知道我的意思。

谢谢，
Siddharth Raina。

附录：
对于大小为1024 x 768的图像，即使对于单个映射操作，JVM也会耗尽堆空间。我们测试中的一些示例代码：

val image = Image from "E:/metallica.jpg"
val redded = image.map(_ & 0xff0000)
redded.display(title = "Redded")

并输出：

"C:Program Files (x86)Javajdk1.6.0_02binjava" -Didea.launcher.port=7533 "-Didea.launcher.bin.path=C:Program Files (x86)JetBrainsIntelliJ IDEA Community Edition 10.0.2bin" -Dfile.encoding=windows-1252 -classpath "C:Program Files (x86)Javajdk1.6.0_02jrelibcharsets.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibdeploy.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibjavaws.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibjce.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibjsse.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibmanagement-agent.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibplugin.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibresources.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibrt.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibextdnsns.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibextlocaledata.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibextsunjce_provider.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibextsunmscapi.jar;C:Program Files (x86)Javajdk1.6.0_02jrelibextsunpkcs11.jar;C:new PhPhoebeoutproductionPhoebe;E:InventoryMarvin.jar;C:scala-2.8.1.finallibscala-library.jar;C:scala-2.8.1.finallibscala-swing.jar;C:scala-2.8.1.finallibscala-dbc.jar;C:new Ph;C:scala-2.8.1.finallibscala-compiler.jar;E:Inventorycommons-math-2.2.jar;E:Inventorycommons-math-2.2-sources.jar;E:Inventorycommons-math-2.2-javadoc.jar;E:Inventoryjmathplot.jar;E:Inventoryjmathio.jar;E:Inventoryjmatharray.jar;E:InventoryJavax Media.zip;E:Inventoryjai-core-1.1.3-alpha.jar;C:Program Files (x86)JetBrainsIntelliJ IDEA Community Edition 10.0.2libidea_rt.jar" com.intellij.rt.execution.application.AppMain phoebe.test.ImageTest
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
    at scala.collection.Iterator$class.toStream(Iterator.scala:1011)
    at scala.collection.IndexedSeqLike$Elements.toStream(IndexedSeqLike.scala:52)
    at scala.collection.Iterator$$anonfun$toStream$1.apply(Iterator.scala:1011)
    at scala.collection.Iterator$$anonfun$toStream$1.apply(Iterator.scala:1011)
    at scala.collection.immutable.Stream$Cons.tail(Stream.scala:565)
    at scala.collection.immutable.Stream$Cons.tail(Stream.scala:557)
    at scala.collection.immutable.Stream$$anonfun$map$1.apply(Stream.scala:168)
    at scala.collection.immutable.Stream$$anonfun$map$1.apply(Stream.scala:168)
    at scala.collection.immutable.Stream$Cons.tail(Stream.scala:565)
    at scala.collection.immutable.Stream$Cons.tail(Stream.scala:557)
    at scala.collection.immutable.Stream$$anonfun$flatten1$1$1.apply(Stream.scala:453)
    at scala.collection.immutable.Stream$$anonfun$flatten1$1$1.apply(Stream.scala:453)
    at scala.collection.immutable.Stream$Cons.tail(Stream.scala:565)
    at scala.collection.immutable.Stream$Cons.tail(Stream.scala:557)
    at scala.collection.immutable.Stream.length(Stream.scala:113)
    at scala.collection.SeqLike$class.size(SeqLike.scala:221)
    at scala.collection.immutable.Stream.size(Stream.scala:48)
    at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:388)
    at scala.collection.immutable.Stream.toArray(Stream.scala:48)
    at phoebe.picasso.Image.force(Image.scala:85)
    at phoebe.picasso.SimpleImageViewer.<init>(SimpleImageViewer.scala:10)
    at phoebe.picasso.Image.display(Image.scala:91)
    at phoebe.test.ImageTest$.main(ImageTest.scala:14)
    at phoebe.test.ImageTest.main(ImageTest.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:115)

Process finished with exit code 1