def rotate(filename, angle):
# open file for use
[size, img_mxclr, img_in] = reader.ppmreader(filename)
# get cos and sin of angle
rad = math.radians(float(angle))
cosine = math.cos(rad)
sine = math.sin(rad)
cen = [int(size[0] / 2), int(size[1] / 2)]
# calculate new bounding rectangle
nsize = [
int(math.ceil(abs(size[0] * cosine) + abs(size[1] * sine))),
int(math.ceil(abs(size[1] * cosine) + abs(size[0] * sine)))
]
ncen = [int(nsize[0] / 2), int(nsize[1] / 2)]
offset = [
int(math.ceil((size[0] - nsize[0]) / 2)),
int(math.ceil((size[1] - nsize[1]) / 2))
]
cdif = [ncen[0] - cen[0], ncen[1] - cen[1]]
out = [[0, 0, 0]] * nsize[0] * nsize[1]
for i in range(nsize[1]):
for j in range(nsize[0]):
# calculate new pixel x,y index
xn = int(
math.cos(rad) * (j - ncen[0]) - math.sin(rad) *
(i - ncen[1])) + ncen[0] - 1
yn = int(
math.sin(rad) * (j - ncen[0]) + math.cos(rad) *
(i - ncen[1])) + ncen[1] - 1
# only move pixels that are within the limits of the image.
xdif = xn - cdif[0]
ydif = yn - cdif[1]
if (xdif < size[0]) and (xdif >= 0) and (ydif <
size[1]) and (ydif >= 0):
out[i * nsize[0] + j] = img_in[ydif * size[0] + xdif]
rot = open('rotated.ppm', 'w')
header = "P3\n# CREATOR: rotation.py\n{0} {1}\n{2}\n".format(
nsize[0], nsize[1], img_mxclr)
rot.write(header)
for p in out:
rot.write("{0} {1} {2}\n".format(p[0], p[1], p[2]))
rot.close
def main(filename):
[size,mx,pixels] = image_in.ppmreader(filename)
out = open('average.pgm','w')
header = "P2\n# CREATOR: average.py\n{0} {1}\n{2}\n".format(size[0],size[1],mx)
out.write(header)
#Apply grayscale
for i in pixels:
g = (i[0]+i[1]+i[2])/3
out.write("%d\n"%g)
out.close()
def main(filename):
[size, mx, pixels] = reader.ppmreader(filename)
header = "P2\n# CREATOR: intensity.py\n{0} {1}\n{2}\n".format(
size[0], size[1], mx)
ppm_out = open('intensity.pgm', 'w')
ppm_out.write(header)
#Apply grayscale
for i in pixels:
g = (max(i[0], i[1], i[2]) + min(i[0], i[1], i[2])) / 2
ppm_out.write("%d\n" % (g))
ppm_out.close()
def main(filename):
#open and extract headers from .ppm file.
[size, mx, pixels] = reader.ppmreader(filename)
header = "P2\n# CREATOR: weighted.py\n{0} {1}\n{2}\n".format(
size[0], size[1], mx)
#create output file to print to.
ppm_out = open('weighted.pgm', 'w')
ppm_out.write(header)
#Apply transformation to pixels and print
for i in pixels:
g = i[0] * 0.299 + i[1] * 0.587 + i[2] * 0.114
ppm_out.write("%d\n" % (g))
ppm_out.close()
def main(filename):
[size, mx, pixels] = image_in.ppmreader(filename)
header = "P2\n# CREATOR: channels.py\n{0} {1}\n{2}\n".format(
size[0], size[1], mx)
r = open('rchannel.pgm', 'w')
g = open('gchannel.pgm', 'w')
b = open('bchannel.pgm', 'w')
r.write(header)
g.write(header)
b.write(header)
#Apply grayscale
for i in pixels:
r.write("%d\n" % (i[0]))
g.write("%d\n" % (i[1]))
b.write("%d\n" % (i[2]))
r.close()
g.close()
b.close()