Miroir de l'Image en Diagonale en Python

Juste pour partager un mode de mise en miroir de la diagonale, en bas à gauche à en haut à droite :

L'étudiant est chargé d'adapter, s'il a besoin d'un miroir à partir de "en haut à droite vers le bas-gauche", ou utiliser l'inverse de la diagonale.

# !! Works only with squared pictures... !!
def diagMirrorPicture(picture):
    height = getHeight(picture)
    width = getWidth(picture)

    if (height != width):
        printNow("Error: The input image is not squared. Found [" + \
                                     str(width) + " x " + str(height) + "] !")
        return None

    newPicture = makeEmptyPicture(width, height)

    mirrorPt = 0
    for x in range(0, width, 1):
        for y in range(mirrorPt, height, 1):
            sourcePixel = getPixel(picture, x, y)
            color = getColor(sourcePixel)

            # Copy bottom-left as is
            targetPixel = getPixel(newPicture, x, y)
            setColor(targetPixel, color)

            # Mirror bottom-left to top right
            targetPixel = getPixel(newPicture, y, x)
            #                                  ^^^^  (simply invert x and y)
            setColor(targetPixel, color)

        # Here we shift the mirror point
        mirrorPt += 1

    return newPicture


file = pickAFile()
picture = makePicture(file)

picture = diagMirrorPicture(picture)

if (picture):
    writePictureTo(picture, "/home/mirror-diag2.png")
    show(picture)

Remarque : Il se comporte comme si nous étions un miroir vertical pour chaque ligne de pixels de manière indépendante, le long de l'axe vertical passant par le mirrorPt point.

De sortie (Peinture par Antoni Tapies):

---

...................................

---

---

Suivantes sont expérimentales et juste pour le fun...

# Draw point, with check if the point is in the image area
def drawPoint(pic, col, x, y):
if (x >= 0) and (x < getWidth(pic)) and (y >= 0) and (y < getHeight(pic)):
px = getPixel(pic, x, y)
setColor(px, col)
# Draw line segment given two points
# From Bresenham's line algorithm :
# http://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm
def drawLine(pic, col, x0, y0, x1, y1):
dx = abs(x1-x0)
dy = abs(y1-y0) 
sx = sy = 0
#sx = 1 if x0 < x1 else -1
#sy = 1 if y0 < y1 else -1
if (x0 < x1): 
sx = 1 
else: 
sx = -1
if (y0 < y1):
sy = 1 
else: 
sy = -1
err = dx - dy
while (True):
drawPoint(pic, col, x0, y0)
if (x0 == x1) and (y0 == y1): 
break
e2 = 2 * err
if (e2 > -dy):
err = err - dy
x0 = x0 + sx
if (x0 == x1) and (y0 == y1):
drawPoint(pic, col, x0, y0)
break
if (e2 <  dx):
err = err + dx
y0 = y0 + sy 
# Works only with squared cropped areas :
# i.e. in [(x0, y0), (x1, y1)], abs(x1-x0) must be equal to abs(y1-y0)
#
# USAGE :
#    * To get bottom reflected to top use x0 > x1 
#    * To get top reflected to bottom use x0 < x1 
def diagCropAndMirrorPicture(pic, startPt, endPt):
w = getWidth(pic)
h = getHeight(pic)
if (startPt[0] < 0) or (startPt[0] >= w) or \
(startPt[1] < 0) or (startPt[1] >= h) or \
(endPt[0] < 0) or (endPt[0] >= w) or \
(endPt[1] < 0) or (endPt[1] >= h):
printNow("Error: The input points must be in the image range !")
return None
new_w = abs(startPt[0] - endPt[0])
new_h = abs(startPt[1] - endPt[1])
if (new_w != new_h):
printNow("Error: The input points do not form a square !")
return None
printNow("Given: (" + str(startPt[0]) + ", " + str(endPt[0]) + ") and (" \
+ str(startPt[1]) + ", " + str(endPt[1]) + ")")
newPicture = makeEmptyPicture(new_w, new_h)
if (startPt[0] < endPt[0]):
offsetX = startPt[0]
switchX = False
switchTB = True
else:
offsetX = endPt[0]
switchX = True
switchTB = False
if (startPt[1] < endPt[1]):
offsetY = startPt[1]
switchY = False
else:
offsetY = endPt[1]
switchY = True
# (switchX  XOR  switchY)
changeDiag = (switchX != switchY)
mirror_pt = 0
for x in range(0, new_w, 1):
for y in range(mirror_pt, new_h, 1):
#for y in range(0, new_h, 1):
oldX = x
oldY = y
if (switchTB):
sourcePixel = getPixel(picture, offsetX+new_w-1- oldX, offsetY+new_h-1- oldY)
else:
sourcePixel = getPixel(picture, offsetX+oldX, offsetY+oldY)
color = getColor(sourcePixel)
if (changeDiag):
newX = new_w-1 - x
newY = new_h-1 - y
#printNow("Change Diag !")
else:
newX = x
newY = y
# Copied half
if (switchTB):
targetPixel = getPixel(newPicture, new_w-1- x, new_h-1- y)
else:
targetPixel = getPixel(newPicture, x, y)
setColor(targetPixel, color)
# Mirror half (simply invert x and y)
if (switchTB):
targetPixel = getPixel(newPicture, new_h-1- newY, new_w-1- newX)
else:
targetPixel = getPixel(newPicture, newY, newX)
setColor(targetPixel, color)
# Here we shift the mirror point
if (not changeDiag):
mirror_pt += 1
return newPicture
file = pickAFile()
pic = makePicture(file)
picture = makePicture(file)
# Draw working area
drawLine(pic, white, 30, 60, 150, 180)
drawLine(pic, white, 30, 180, 150, 60)
drawLine(pic, black, 30, 60, 30, 180)
drawLine(pic, black, 30, 60, 150, 60)
drawLine(pic, black, 150, 60, 150, 180)
drawLine(pic, black, 30, 180, 150, 180)
show(pic)
writePictureTo(pic, "D:\\pic.png")
# Build cropped and mirrored areas
pic1 = diagCropAndMirrorPicture(picture, (150, 60), (30, 180))
pic2 = diagCropAndMirrorPicture(picture, (30, 180), (150, 60))
pic3 = diagCropAndMirrorPicture(picture, (150, 180), (30, 60))
pic4 = diagCropAndMirrorPicture(picture, (30, 60), (150, 180))
# Show cropped and mirrored areas
if (pic1):
writePictureTo(pic1, "D:\\pic1.png")
show(pic1)
if (pic2):
writePictureTo(pic2, "D:\\pic2.png")
show(pic2)
if (pic3):
writePictureTo(pic3, "D:\\pic3.png")
show(pic3)
if (pic4):
writePictureTo(pic4, "D:\\pic4.png")
show(pic4)

---

............................................................................................................

..............

---

OriginalL'auteur Gauthier Boaglio