IMAGO

Resizing an image

(resize *image* 400 150)
    

 

Applying an emboss effect

(emboss *image* :angle (* pi 0.75) :depth 1.0)
    

 

Using a custom convolution kernel

(let ((kernel #2A((0  0  0  0  0)
                  (0  0  1  0  0)
                  (0  1 -4  1  0)
                  (0  0  1  0  0)
                  (0  0  0  0  0))))
  (convolve *image* kernel 1 0))
    

 

Inverting a rectangular region

(do-region-pixels (*image* color x y 70 65 140 125)
  (setf color (invert-color color)))
    

 

Manipulating color components

(do-image-pixels (*image* color x y)
  (multiple-value-bind (r g b) (color-rgb color)
    (setf color (make-color b
                            (floor (* g 0.8))
                            r))))
    

 

Composing pictures

(let ((operator (default-compose-operator *image1*)))
  (compose nil *image1* *image2* 20 20 operator))
    

Drawing simple primitives

(let ((points '(83 45 73 150 73 150 198 106 198 106 83 45)))
  (draw-polygon *image* points +white+ :closed t))
(draw-circle *image* 83 45 15 +white+)
(draw-circle *image* 73 150 15 +white+)
(draw-circle *image* 198 106 15 +white+)
(draw-bezier-curve *image* 10 80 150 60 100 170 200 170 +red+)
(draw-line *image* 0 5 254 5 +yellow+)
(draw-line *image* 0 10 254 10 +yellow+ :dash-length 1 :dash-interval 1)
(draw-line *image* 0 15 254 15 +yellow+ :dash-length 4 :dash-interval 2)
    

 

A more complex example

(defun sea-view (image)
  (let ((image2 (flip nil image :horizontal)))
    (do-image-pixels (image2 color x y)
      (multiple-value-bind (r g b)
          (color-rgb color)
        (setf color (make-color (floor r 3) (floor g 3) (floor b 2)))))
    (let* ((width (image-width image))
           (height (image-height image))
           (result (make-instance (class-of image)
                                  :width width :height (* height 2))))
      (copy result image)
      (copy result image2 :dest-y height)
      result)))