def scanlines(self, width, height, offsets):
"""
Merge multi-page screenshots and yield scanlines.
"""
overlaps = [height - offset for offset in offsets]
# print 'offsets: ', offsets
# print 'overlaps:', overlaps
total = 0
row_bytes = 3 * width
for index in range(0, len(overlaps) + 1):
top = 0
bottom = 0
if index == 0:
top = self.top_skip
else:
top = overlap_top(overlaps[index - 1])
if index == len(offsets):
bottom = self.bottom_skip
else:
bottom = overlap_bottom(overlaps[index])
bottom = height - bottom
segment = bottom - top
total += segment
filename = self.page_filename(index + 1)
print filename, top, bottom, segment, total
infile = open(filename, 'rb')
hashmatch.read_ppm_header(infile)
infile.seek(top * row_bytes, 1)
for dummy in range(top, bottom):
scanline = array('B')
scanline.fromfile(infile, row_bytes)
yield scanline
infile.close()
def scanlines(self, offsets):
"""
Merge multi-page screenshots and yield scanlines.
"""
overlaps = [self.height - offset for offset in offsets]
# print "offsets: ", offsets
# print "overlaps:", overlaps
total = 0
row_bytes = 3 * self.width
for index in range(0, len(overlaps) + 1):
top = 0
bottom = 0
if index == 0:
top = self.top_skip
else:
top = overlap_top(overlaps[index-1])
if index == len(offsets):
bottom = self.bottom_skip
else:
bottom = overlap_bottom(overlaps[index])
bottom = self.height - bottom
segment = bottom - top
total += segment
filename = self.page_filename(index+1)
print filename, top, bottom, segment, total
infile = open(filename, 'rb')
hashmatch.read_ppm_header(infile)
infile.seek(top*row_bytes, 1)
for dummy in range(top, bottom):
scanline = array('B')
scanline.fromfile(infile, row_bytes)
yield scanline
infile.close()
def check_screenshot(self, filename):
"""
Check if the screenshot file looks ok.
"""
if not os.path.exists(filename):
raise RuntimeError("screenshot file %s not found" % filename)
if not os.path.getsize(filename):
raise RuntimeError("screenshot file %s is empty" % filename)
magic, width, height, maxval = hashmatch.read_ppm_header(open(filename, "rb"))
if magic != "P6":
raise RuntimeError("%s isn't a PPM file with 24 bpp" % filename)
if width != self.width or height != self.height:
raise RuntimeError(
"%s has %dx%d pixels, not the requested size %dx%d" % (filename, width, height, self.width, self.height)
)
if maxval != 255:
raise RuntimeError("%s has maxval %d, but only maxval 255 is supported" % (maxval, filename))
def check_screenshot(self, filename):
"""
Check if the screenshot file looks ok.
"""
if not os.path.exists(filename):
raise RuntimeError("screenshot file %s not found" % filename)
if not os.path.getsize(filename):
raise RuntimeError("screenshot file %s is empty" % filename)
magic, width, height, maxval = hashmatch.read_ppm_header(
open(filename, 'rb'))
if magic != 'P6':
raise RuntimeError("%s isn't a PPM file with 24 bpp" % filename)
if width != self.width or height != self.height:
raise RuntimeError(
"%s has %dx%d pixels, not the requested size %dx%d" %
(filename, width, height, self.width, self.height))
if maxval != 255:
raise RuntimeError(
"%s has maxval %d, but only maxval 255 is supported" %
(maxval, filename))
def browsershot(self, pngfilename='browsershot.png'):
"""
Take a number of screenshots and merge them into one tall image.
"""
filename = self.page_filename(1)
self.screenshot(filename)
self.check_screenshot(filename)
magic, width, height, maxval = hashmatch.read_ppm_header(
open(filename, 'rb'))
assert magic == 'P6', "%s isn't a PPM file with 24 bpp" % filename
assert maxval == 255, "%s doesn't have 24 bits per pixel" % filename
offsets = self.scroll_pages(height)
total = height + sum(offsets) - self.top_skip - self.bottom_skip
# print 'total:', total
scanlines = self.scanlines(width, height, offsets)
outfile = file(pngfilename, 'wb')
writer = png.Writer(width, total)
writer.write(outfile, scanlines)
outfile.close()
