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--- fp:lab07 [2022/04/20 14:22]
pdmatei
+++ fp:lab07 [2022/05/03 17:25] (current)
pdmatei
@@ Line 27: / Line 27: @@
 // define your functions here
-def main(args: Array[String]) = {
+  def main(args: Array[String]) = {
-// write your tests here
+  // write your tests here
-}
+  }
 }
 </code>
-**7.1.** Write a function
+**7.1.** Write a function which converts an image to a string (Hint: you can draw inspiration from a similar one from the lecture):
+<code scala>
+def show(m: Img): String = ???
+</code>
+**7.2.** Write a function which performs a horizontal flip on an image. Try to first visualise (you may use pen and paper) how the transformation would look like.
+<code scala>
+def hFlip(img: Img): Img = ???
+</code>
+**7.3.** Write a function which performs vertical flip.
+<code scala>
+def vFlip(img: Img): Img = ???
+</code>
+**7.4.**  Write a function which performs a 90 degrees rotation to the right. (Hint: you need an ingredient from the lecture. Also, note that there are multiple possible implementations.)
+<code scala>
+def rot90Right(img: Img): Img = ???
+</code>
+**7.5.** Write a function which performs a 90 degrees rotation to the left.
+<code scala>
+def rot90Left(img: Img): Img = ???
+</code>
+**7.6.** Write a function which inverts an image (values 0 become 255, 1 - 254, and so forth).
+**7.7.** Write a function which crops a given image, using two, two-dimensional coordinates: the higher-left point x and y, and the lower-right point x and y. An example is shown below:
+<code scala>
+val img = List(List(0,0,1,0,0), List(0,1,0,1,0), List(0,1,1,1,0), List(1,0,0,0,1), List(1,0,0,0,1))
+/*
+0 1 0 0
+*     0 1 0 1 0                                           1 0 1
+*     0 1 1 1 0     cropping from 1,1  to  2,3  yields:   1 1 1
+*     1 0 0 0 1
+*     1 0 0 0 1
+ */
+def cropAt(img: Img, xSt:Int, ySt:Int, xEnd: Int, yEnd: Int): Img = ??
+</code>
+**7.8.** Write a function which returns a list of all positions which have pixels of larger intensity than x
+<code scala>
+def largerPos(img: Img, int: Int): List[(Int,Int)] = ???
+</code>
+**7.9.** Write a function which adds ''x'' to the intensity of each pixel.
+<code scala>
+def contrast(x: Int)(img: Img): Img = ???
+</code>
+**7.10.** Write a function which takes two images ''X'' and ''Y'' and //glues// them on the horizontal axis (the resulting image will be ''XY'')
+<code scala>
+def hglue(img1: Img, img2: Img): Img = ???
+</code>
+**7.11.** Write a function which takes two images ''X'' and ''Y'' and //glues// them on the vertical axis:
+<code scala>
+def vglue(img1: Img, img2: Img): Img = ???
+</code>
+**7.12.** Define a function that takes a **square** image, and draws two diagonal lines of intensity 1 across it. Use ''_.until(_)'' and ''_.toList''.
+<code scala>
+def diag(img: Img): Img = ???
+</code>
+**7.13.** Define a function which blurs an image as follows:
+  * for each pixel p of intensity > 1: make all neighbouring pixels of intensity 0 equal to p-1 (including diagonals).
+  * if some pixel of intensity 0 is in the vicinity of two different >1 pixels of different intensities, the one which is larger should be taken into account
+  * to make the implementation easier, you do not need to implement the blur on the image edges.
+<code scala>
+def blur(img: Img): Img = ???
+</code>
+**7.14. (!) ** Define a function which builds an effect of intensity x as shown below:
+<code scala>
+val img2 = List(
+  List(0,0,0,0,0,0,0,0,0),
+  List(0,0,0,0,0,0,0,0,0),
+  List(0,0,0,0,0,0,0,0,0),
+  List(0,0,0,0,1,0,0,0,0),
+  List(0,0,0,1,2,1,0,0,0),
+  List(0,0,0,0,1,0,0,0,0),
+  List(0,0,0,0,0,0,0,0,0),
+  List(0,0,0,0,0,0,0,0,0),
+  List(0,0,0,0,0,0,0,0,0)
+)
+/*
+Before:                   After (for x = 2)
+0 0 0 0 0 0 0 0      0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0      0 0 1 1 1 1 1 0 0
+0 0 0 0 0 0 0 0      0 1 1 2 2 2 1 1 0
+0 0 0 1 0 0 0 0      0 1 2 2 3 2 2 1 0
+0 0 1 2 1 0 0 0      0 1 2 3 4 3 2 1 0
+0 0 0 1 0 0 0 0      0 1 2 2 3 2 2 1 0
+0 0 0 0 0 0 0 0      0 1 1 2 2 2 1 0 0
+0 0 0 0 0 0 0 0      0 0 1 1 1 1 1 0 0
+0 0 0 0 0 0 0 0      0 0 0 0 0 0 0 0 0
+Hint: a single foldRight is sufficient. Which is the list you should apply it on?
+ */
+def effect(intensity: Int, img: Img): Img = ???
+</code>