[FIXED] How to make a part of the picture grayscale in JES?

Issue

Hi there I'm trying to play around with my code and can't really seem to figure out how to make part of my code into a grayscale. This is my code:

def grayScale(picture):
      xstop=getWidth(picture)/2
      ystop=getHeight(picture)/2
      for x in range(0,xstop):
          for y in range(0,ystop):
          oldpixel= getPixel(picture,x,y)
          colour=getColor(oldpixel)
          newColor=(getRed(oldpixel),getGreen(oldpixel),getBlue(oldpixel))/3
          setColor(picture,(newColor,newColor,newColor))
      repaint(picture)


nP=makePicture(pickAFile())
show(nP)

Any help is appreciated, really trying hard to understand this. Thanks again for your help!

Error shown:

grayScale(nP) The error was: 'tuple' and 'int'

Inappropriate argument type. An attempt was made to call a function with a parameter of an invalid type. This means that you did something such as trying to pass a string to a method that is expecting an integer. Please check line 8 of /Users/enochphan/Desktop/test

Solution

There are a few things giving you trouble here:

• Indenting of your code after the y for loop (I'm guessing you want all of the height to traversed).
• The new colour is just the average of your current pixels, so you need to use addition to add them before dividing by three.
• setColor() takes a pixel and a color object. The pixel you want to change is oldpixel, and the color object is created using makeColor().

Here is code with all the fixes implemented:

def grayScale(picture):
      xstop=getWidth(picture)/2
      ystop=getHeight(picture)/2
      for x in range(0,xstop):
          for y in range(0,ystop):
            oldpixel= getPixel(picture,x,y)
            colour=getColor(oldpixel)
            newColor = (getRed(oldpixel)+getGreen(oldpixel)+getBlue(oldpixel))/3
            setColor(oldpixel,makeColor(newColor,newColor,newColor))
      repaint(picture)    

Answered By - Vaderico

Answer Checked By - Gilberto Lyons (PHPFixing Admin)