我如何计算 Scala 语言中所有的红色、绿色和蓝色？

Question

我在计算图片中每种颜色的 RGB 时遇到问题。首先，我从光盘加载图片，然后读取这张图片。但我不会分开颜色并计算有多少像素是红色、绿色或蓝色。

    package com.szymonBikowski

import java.awt.Color
import java.awt.image.BufferedImage
import java.io.File

import javax.imageio.ImageIO
import com.szymonBikowski.loadImage.getListOffiles
import org.w3c.dom.css.RGBColor

object photoAnalizer {

  var path = "/home/biku/Pulpit/In"
  var correctFile = "/home/biku/Pulpit/In/c.jpg"
  var splitPath = correctFile.split("""/""")
  var filePath = loadImage.getListOffiles(path)
  var filename = splitPath(splitPath.length-1)
  var correctFilePathToSave = "/home/biku/Pulpit/Out/" + filename

//  for (v <- splitPath)
//    {
//      println(v)
//    }
  def photoReader(image: BufferedImage): BufferedImage = {
  var numberOfRed = 0
  var numberOfGreen = 0
  var numberOfBlue = 0
  val lightGreen = new Color(0,255,0)
  val darkGreen = new Color(0,100,0)

  // width and height load photo
    val width = image.getWidth
    val height = image.getHeight

  // create new image with the same size like load photo
    val imageOut = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB)

  // copy pixels from load photo(horizontally)
    for (x <- 0 until width)
      for (y <- 0 until height) {
        imageOut.setRGB(x,y, image.getRGB(width-x-1,y) & 0xffffff)

        // count pixels R&G&B
        val color = new Color(image.getRGB(x,y))
        if(isBetween(color, lightGreen, darkGreen))
          numberOfGreen += 1
      }

  imageOut
  }

  def isBetween(color: Color, color1: Color, color2: Color): Boolean = {
    color.getRed >= color1.getRed && color.getRed <= color2.getRed &&
      color.getBlue >= color1.getBlue && color.getBlue <= color2.getBlue &&
      color.getGreen <= color1.getGreen && color.getGreen >= color2.getGreen
  }

  def imageLoad(): Unit ={
    //read heiht and width from load photo
    val photo = ImageIO.read(new File(correctFile))
    val photo2 = photoReader(photo)
  }
imageLoad()

  def main(args: Array[String]): Unit = {

  }




}

我尝试直接使用颜色，然后尝试使用上面的隔间。请有人帮帮我好吗？

Answer 1

我认为您可以使用 Color 中的 getRed()、getGreen()、getBlue() 方法 class:

import java.awt.Color
import java.awt.image.BufferedImage

def photoReader(image: BufferedImage): BufferedImage = {
  // width and height load photo
  val width = image.getWidth
  val height = image.getHeight

  // create new image with the same size like load photo
  val imageOut = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB)

  // this is sequence of rgb for each pair x, y
  val rgbs = for {
    x <- 0 until width
    y <- 0 until height
    color = new Color(image.getRGB(x,y))
  } yield (color.getRed, color.getGreen, color.getBlue)
  // here you sum all red, green, blue values for all x, y pairs
  val (numberOfRed, numberOfGreen, numberOfBlue) = rgbs.fold(0, 0, 0){
    case ((sumRed, sumGreen, sumBlue), (red, green, blue)) =>
      ((sumRed + red), (sumBlue + blue), (sumGreen + green))
  }
  imageOut
}

更新： yield 来自 for-comprehension 构造。它将循环迭代的结果收集到序列中（类似于列表），您可以指定表达式来收集您需要收集的内容。如果需要收集rgb-colors，可以收集每种颜色的tuple3，这段代码的结果：

for {
  x <- 0 until width
  y <- 0 until height
  color = new Color(image.getRGB(x,y))
} yield (color.getRed, color.getGreen, color.getBlue)

将是元组序列，其中每个元素都是元组 - 每对 (x, y) 的 (red, green, blue)。之后，您可以使用 fold 函数对所有元组求和。它需要累加器，在我们的例子中是带有零的 tuple3 - (0, 0, 0) 并将序列的每个元素添加到它。如果您需要获取 rgb，您可以通过 rgb 元组结束方法并更改签名，同时更改函数名称：

def getRGB(image: BufferedImage): (Int, Int, Int) = {
  ...
  (numberOfRed, numberOfGreen, numberOfBlue)
}

我如何计算 Scala 语言中所有的红色、绿色和蓝色？

How can I count all red and green and blue color in Scala language?

rgb

scala

image-processing