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authorGuido van Rossum <guido@python.org>1997-01-15 19:19:19 (GMT)
committerGuido van Rossum <guido@python.org>1997-01-15 19:19:19 (GMT)
commit1ce7c6fde8a8879ec64242dc0d01b660b934633a (patch)
treef78fea84c78ace252a19a20cd1888dd3c220657f /Lib/plat-irix6/jpeg.py
parent6ad8d13fe2a9c023969d184554aeb1e557115f57 (diff)
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Irix 6 specific files -- thanks Sjoerd!
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+# Implement 'jpeg' interface using SGI's compression library
+
+# XXX Options 'smooth' and 'optimize' are ignored.
+
+# XXX It appears that compressing grayscale images doesn't work right;
+# XXX the resulting file causes weirdness.
+
+error = 'jpeg.error' # Exception
+
+options = {'quality': 75, 'optimize': 0, 'smooth': 0, 'forcegray': 0}
+
+comp = None
+decomp = None
+
+def compress(imgdata, width, height, bytesperpixel):
+ global comp
+ import cl, CL
+ if comp is None: comp = cl.OpenCompressor(CL.JPEG)
+ if bytesperpixel == 1:
+ format = CL.GRAYSCALE
+ elif bytesperpixel == 4:
+ format = CL.RGBX
+ if options['forcegray']:
+ iformat = CL.GRAYSCALE
+ else:
+ iformat = CL.YUV
+ # XXX How to support 'optimize'?
+ params = [CL.IMAGE_WIDTH, width, CL.IMAGE_HEIGHT, height, \
+ CL.ORIGINAL_FORMAT, format, \
+ CL.ORIENTATION, CL.BOTTOM_UP, \
+ CL.QUALITY_FACTOR, options['quality'], \
+ CL.INTERNAL_FORMAT, iformat, \
+ ]
+ comp.SetParams(params)
+ jpegdata = comp.Compress(1, imgdata)
+ return jpegdata
+
+def decompress(jpegdata):
+ global decomp
+ import cl, CL
+ if decomp is None: decomp = cl.OpenDecompressor(CL.JPEG)
+ headersize = decomp.ReadHeader(jpegdata)
+ params = [CL.IMAGE_WIDTH, 0, CL.IMAGE_HEIGHT, 0, CL.INTERNAL_FORMAT, 0]
+ decomp.GetParams(params)
+ width, height, format = params[1], params[3], params[5]
+ if format == CL.GRAYSCALE or options['forcegray']:
+ format = CL.GRAYSCALE
+ bytesperpixel = 1
+ else:
+ format = CL.RGBX
+ bytesperpixel = 4
+ # XXX How to support 'smooth'?
+ params = [CL.ORIGINAL_FORMAT, format, \
+ CL.ORIENTATION, CL.BOTTOM_UP, \
+ CL.FRAME_BUFFER_SIZE, width*height*bytesperpixel]
+ decomp.SetParams(params)
+ imgdata = decomp.Decompress(1, jpegdata)
+ return imgdata, width, height, bytesperpixel
+
+def setoption(name, value):
+ if type(value) <> type(0):
+ raise TypeError, 'jpeg.setoption: numeric options only'
+ if name == 'forcegrey':
+ name = 'forcegray'
+ if not options.has_key(name):
+ raise KeyError, 'jpeg.setoption: unknown option name'
+ options[name] = int(value)
+
+def test():
+ import sys
+ if sys.argv[1:2] == ['-g']:
+ del sys.argv[1]
+ setoption('forcegray', 1)
+ if not sys.argv[1:]:
+ sys.argv.append('/usr/local/images/data/jpg/asterix.jpg')
+ for file in sys.argv[1:]:
+ show(file)
+
+def show(file):
+ import gl, GL, DEVICE
+ jpegdata = open(file, 'r').read()
+ imgdata, width, height, bytesperpixel = decompress(jpegdata)
+ gl.foreground()
+ gl.prefsize(width, height)
+ win = gl.winopen(file)
+ if bytesperpixel == 1:
+ gl.cmode()
+ gl.pixmode(GL.PM_SIZE, 8)
+ gl.gconfig()
+ for i in range(256):
+ gl.mapcolor(i, i, i, i)
+ else:
+ gl.RGBmode()
+ gl.pixmode(GL.PM_SIZE, 32)
+ gl.gconfig()
+ gl.qdevice(DEVICE.REDRAW)
+ gl.qdevice(DEVICE.ESCKEY)
+ gl.qdevice(DEVICE.WINQUIT)
+ gl.qdevice(DEVICE.WINSHUT)
+ gl.lrectwrite(0, 0, width-1, height-1, imgdata)
+ while 1:
+ dev, val = gl.qread()
+ if dev in (DEVICE.ESCKEY, DEVICE.WINSHUT, DEVICE.WINQUIT):
+ break
+ if dev == DEVICE.REDRAW:
+ gl.lrectwrite(0, 0, width-1, height-1, imgdata)
+ gl.winclose(win)
+ # Now test the compression and write the result to a fixed filename
+ newjpegdata = compress(imgdata, width, height, bytesperpixel)
+ open('/tmp/j.jpg', 'w').write(newjpegdata)