;;; File:
;;;   hw13.scm
;;; Authors:
;;;   Samuel A. Rebelsky (compiler, editor)
;;;   Various members of CSC151 2007S (see below)
;;; Summary:
;;;   A variety of interesting image manpiulation procedures.  Each
;;;   procedure should be used, along with an image to modify, as a
;;;   parameter to modify-image!, as in
;;;     (modify-image! sam make-even-more-silly) 
;;; Procedures:

;;; Procedure:
;;;   hw13
;;; Parameters:
;;;   None
;;; Perpetrator:
;;;   Sam Rebelsky
;;; Purpose:
;;;   To make it easier to reload this file after changes
(define hw13
  (lambda ()
    (load "/home/rebelsky/Web/Courses/CS151/2007S/Examples/hw13.scm")))

;;; Procedure:
;;;   cartoon
;;; Perpetrators:
;;;   Paden Roder and Cyrus Witthuas
(define cartoon
  (lambda (color) 
    (let* ((round-to-50 
           (lambda (number) 
             (cond 
               ((and (<= 0 number) (< number 25)) 0) 
               ((and (<= 25 number) (< number 75)) 50) 
               ((and (<= 75 number) (< number 125)) 100) 
               ((and (<= 125 number) (< number 175)) 150) 
               ((and (<= 175 number) (< number 225)) 200) 
               (else 250)))) 
          (round-to-100 
           (lambda (number) 
             (cond 
               ((and (<= 0 number) (< number 50)) 0) 
               ((and (<= 50 number) (< number 150)) 100) 
               ((and (<= 150 number) (< number 250)) 200) 
               (else 250)))) 
          (round-to-125 
           (lambda (number) 
             (cond 
               ((and (<= 0 number) (< number 67)) 0) 
               ((and (<= 67 number) (< number 192)) 125) 
               (else 250)))))
      (rgb (round-to-50 (green color)) 
           (round-to-50 (blue color)) 
           (round-to-50 (red color))))))

;;; Procedure:
;;;   transform-portrait-color
;;; Perpetrator:
;;;   Jordan Medalia
(define transform-portrait-color 
  (lambda (color)
    (let ((newred (if (< (red color) 150) 
                     (+ (red color) 50) 
                     (- (red color) 50))) 
          (newgreen (if (< (green color) 150) 
                        (+ (green color) 50) 
                        (- (green color) 50))) 
          (newblue (if (< (blue color) 150) 
                       (+ (blue color) 50) 
                       (- (blue color) 50))))
     (rgb newred newgreen newblue))))