def get_image(self, x, y, width, height):
image = None
if not self.capture:
self.capture = setup_capture(self.window)
assert self.capture, "no capture method available"
ox, oy = self.geometry[:2]
image = image or self.capture.get_image(ox + x, oy + y, width, height)
if ox > 0 or oy > 0:
#all we want to do here is adjust x and y...
#FIXME: this is inefficient and may take a copy of the pixels:
# but the XImageCapture cannot share buffers, so adjusting coordinates is not enough
image = ImageWrapper(x,
y,
width,
height,
image.get_pixels(),
image.get_pixel_format(),
image.get_depth(),
image.get_rowstride(),
image.get_bytesperpixel(),
image.get_planes(),
thread_safe=True,
palette=None)
return image
def test_sub_image(self):
X = 0
Y = 0
W = 640
H = 480
D = 24
buf = bytearray(W * H * 4)
#the pixel value is derived from the sum of its coordinates (modulo 256)
for x in range(W):
for y in range(H):
#4 bytes per pixel:
for i in range(4):
buf[y * (W * 4) + x * 4 + i] = (x + y) % 256
img = ImageWrapper(X,
Y,
W,
H,
buf,
"RGBX",
D,
W * 4,
planes=ImageWrapper.PACKED,
thread_safe=True)
#verify attributes:
assert img.get_x() == X
assert img.get_y() == Y
assert img.get_target_x() == X
assert img.get_target_y() == Y
assert img.get_width() == W
assert img.get_height() == H
assert img.get_depth() == D
assert img.get_bytesperpixel() == 4
assert img.get_rowstride() == W * 4
assert img.get_size() == W * 4 * H
assert img.has_pixels()
assert len(img.get_geometry()) == 5
assert img.get_pixel_format() == "RGBX"
assert img.get_planes() == ImageWrapper.PACKED
#print("image pixels head=%s" % (binascii.hexlify(img.get_pixels()[:128]), ))
for x in range(3):
SW, SH = 6, 6
sub = img.get_sub_image(x, 0, SW, SH)
#print("%s.get_sub_image%s=%s" % (img, (x, 0, SW, SH), sub))
#this is only true for the pure python ImageWrapper:
#(the X11 image wrapper references the same underlying XShm pixels, with the same rowstride)
assert sub.get_rowstride() == (SW * 4)
sub_buf = sub.get_pixels()
#print("pixels for %ix%i: %i" % (SW, SH, len(sub_buf)))
#print("pixels=%s" % (binascii.hexlify(sub_buf), ))
#verify that the pixels are set to 1 / 0:
for y in range(SH):
v = (x + y) % 256
for i in range(4):
av = sub_buf[y * (SW * 4) + i]
if av != v:
raise Exception("""expected value %#x for pixel (0, %i)
of sub-image %s at (%i, 0), but got %#x"""
% (v, y, sub, x, av))
start = monotonic_time()
copy = img.get_sub_image(0, 0, W, H)
end = monotonic_time()
if SHOW_PERF:
print("image wrapper full %ix%i copy speed: %iMB/s" %
(W, H, (W * 4 * H) / (end - start) / 1024 / 1024))
assert copy.get_pixels() == img.get_pixels()
total = 0
N = 10
for i in range(N):
region = (W // 4 - N // 2 + i, H // 4 - N // 2 + i, W // 2, H // 2)
start = monotonic_time()
copy = img.get_sub_image(*region)
end = monotonic_time()
total += end - start
if SHOW_PERF:
print("image wrapper sub image %ix%i copy speed: %iMB/s" %
(W // 2, H // 2, N *
(W // 2 * 4 * H // 2) / total / 1024 / 1024))
#invalid sub-image should fail:
for x, y, w, h in (
(-1, 0, 1, 1),
(0, -1, 1, 1),
(0, 0, 0, 1),
(0, 0, 1, 0),
(1, 0, W, 1),
(0, 1, 1, H),
):
try:
img.get_sub_image(x, y, w, h)
except Exception:
pass
else:
raise Exception(
"sub image of %s with coords %s should have failed" %
(img, (x, y, w, h)))
#freeze is a no-op in the default wrapper:
assert img.freeze() is False
img.clone_pixel_data()