Encoded API

This feature is only possible since PyTango 7.1.4

class tango.EncodedAttribute
decode_gray16(da, extract_as=<ExtensionMock name='_tango.ExtractAs.Numpy' id='139923416142680'>)

Decode a 16 bits grayscale image (GRAY16) and returns a 16 bits gray scale image.

param da:DeviceAttribute that contains the image
type da:DeviceAttribute
param extract_as:
 defaults to ExtractAs.Numpy
type extract_as:
 ExtractAs
return:the decoded data
  • In case String string is choosen as extract method, a tuple is returned:
    width<int>, height<int>, buffer<str>
  • In case Numpy is choosen as extract method, a numpy.ndarray is returned with ndim=2, shape=(height, width) and dtype=numpy.uint16.
  • In case Tuple or List are choosen, a tuple<tuple<int>> or list<list<int>> is returned.

Warning

The PyTango calls that return a DeviceAttribute (like DeviceProxy.read_attribute() or DeviceProxy.command_inout()) automatically extract the contents by default. This method requires that the given DeviceAttribute is obtained from a call which DOESN’T extract the contents. Example:

dev = tango.DeviceProxy("a/b/c")
da = dev.read_attribute("my_attr", extract_as=tango.ExtractAs.Nothing)
enc = tango.EncodedAttribute()
data = enc.decode_gray16(da)
decode_gray8(da, extract_as=<ExtensionMock name='_tango.ExtractAs.Numpy' id='139923416142680'>)

Decode a 8 bits grayscale image (JPEG_GRAY8 or GRAY8) and returns a 8 bits gray scale image.

param da:DeviceAttribute that contains the image
type da:DeviceAttribute
param extract_as:
 defaults to ExtractAs.Numpy
type extract_as:
 ExtractAs
return:the decoded data
  • In case String string is choosen as extract method, a tuple is returned:
    width<int>, height<int>, buffer<str>
  • In case Numpy is choosen as extract method, a numpy.ndarray is returned with ndim=2, shape=(height, width) and dtype=numpy.uint8.
  • In case Tuple or List are choosen, a tuple<tuple<int>> or list<list<int>> is returned.

Warning

The PyTango calls that return a DeviceAttribute (like DeviceProxy.read_attribute() or DeviceProxy.command_inout()) automatically extract the contents by default. This method requires that the given DeviceAttribute is obtained from a call which DOESN’T extract the contents. Example:

dev = tango.DeviceProxy("a/b/c")
da = dev.read_attribute("my_attr", extract_as=tango.ExtractAs.Nothing)
enc = tango.EncodedAttribute()
data = enc.decode_gray8(da)
decode_rgb32(da, extract_as=<ExtensionMock name='_tango.ExtractAs.Numpy' id='139923416142680'>)

Decode a color image (JPEG_RGB or RGB24) and returns a 32 bits RGB image.

param da:DeviceAttribute that contains the image
type da:DeviceAttribute
param extract_as:
 defaults to ExtractAs.Numpy
type extract_as:
 ExtractAs
return:the decoded data
  • In case String string is choosen as extract method, a tuple is returned:
    width<int>, height<int>, buffer<str>
  • In case Numpy is choosen as extract method, a numpy.ndarray is returned with ndim=2, shape=(height, width) and dtype=numpy.uint32.
  • In case Tuple or List are choosen, a tuple<tuple<int>> or list<list<int>> is returned.

Warning

The PyTango calls that return a DeviceAttribute (like DeviceProxy.read_attribute() or DeviceProxy.command_inout()) automatically extract the contents by default. This method requires that the given DeviceAttribute is obtained from a call which DOESN’T extract the contents. Example:

dev = tango.DeviceProxy("a/b/c")
da = dev.read_attribute("my_attr", extract_as=tango.ExtractAs.Nothing)
enc = tango.EncodedAttribute()
data = enc.decode_rgb32(da)
encode_gray16(gray16, width=0, height=0)

Encode a 16 bit grayscale image (no compression)

param gray16:an object containning image information
type gray16:str or buffer or numpy.ndarray or seq< seq<element> >
param width:image width. MUST be given if gray16 is a string or if it is a numpy.ndarray with ndims != 2. Otherwise it is calculated internally.
type width:int
param height:image height. MUST be given if gray16 is a string or if it is a numpy.ndarray with ndims != 2. Otherwise it is calculated internally.
type height:int

Note

When numpy.ndarray is given:

  • gray16 MUST be CONTIGUOUS, ALIGNED
  • if gray16.ndims != 2, width and height MUST be given and gray16.nbytes/2 MUST match width*height
  • if gray16.ndims == 2, gray16.itemsize MUST be 2 (typically, gray16.dtype is one of numpy.dtype.int16, numpy.dtype.uint16, numpy.dtype.short or numpy.dtype.ushort)
Example:

:

def read_myattr(self, attr):
    enc = tango.EncodedAttribute()
    data = numpy.arange(100, dtype=numpy.int16)
    data = numpy.array((data,data,data))
    enc.encode_gray16(data)
    attr.set_value(enc)
encode_gray8(gray8, width=0, height=0)

Encode a 8 bit grayscale image (no compression)

param gray8:an object containning image information
type gray8:str or numpy.ndarray or seq< seq<element> >
param width:image width. MUST be given if gray8 is a string or if it is a numpy.ndarray with ndims != 2. Otherwise it is calculated internally.
type width:int
param height:image height. MUST be given if gray8 is a string or if it is a numpy.ndarray with ndims != 2. Otherwise it is calculated internally.
type height:int

Note

When numpy.ndarray is given:

  • gray8 MUST be CONTIGUOUS, ALIGNED
  • if gray8.ndims != 2, width and height MUST be given and gray8.nbytes MUST match width*height
  • if gray8.ndims == 2, gray8.itemsize MUST be 1 (typically, gray8.dtype is one of numpy.dtype.byte, numpy.dtype.ubyte, numpy.dtype.int8 or numpy.dtype.uint8)
Example:

:

def read_myattr(self, attr):
    enc = tango.EncodedAttribute()
    data = numpy.arange(100, dtype=numpy.byte)
    data = numpy.array((data,data,data))
    enc.encode_gray8(data)
    attr.set_value(enc)
encode_jpeg_gray8(gray8, width=0, height=0, quality=100.0)

Encode a 8 bit grayscale image as JPEG format

param gray8:an object containning image information
type gray8:str or numpy.ndarray or seq< seq<element> >
param width:image width. MUST be given if gray8 is a string or if it is a numpy.ndarray with ndims != 2. Otherwise it is calculated internally.
type width:int
param height:image height. MUST be given if gray8 is a string or if it is a numpy.ndarray with ndims != 2. Otherwise it is calculated internally.
type height:int
param quality:Quality of JPEG (0=poor quality 100=max quality) (default is 100.0)
type quality:float

Note

When numpy.ndarray is given:

  • gray8 MUST be CONTIGUOUS, ALIGNED
  • if gray8.ndims != 2, width and height MUST be given and gray8.nbytes MUST match width*height
  • if gray8.ndims == 2, gray8.itemsize MUST be 1 (typically, gray8.dtype is one of numpy.dtype.byte, numpy.dtype.ubyte, numpy.dtype.int8 or numpy.dtype.uint8)
Example:

:

def read_myattr(self, attr):
    enc = tango.EncodedAttribute()
    data = numpy.arange(100, dtype=numpy.byte)
    data = numpy.array((data,data,data))
    enc.encode_jpeg_gray8(data)
    attr.set_value(enc)
encode_jpeg_rgb24(rgb24, width=0, height=0, quality=100.0)

Encode a 24 bit rgb color image as JPEG format.

param rgb24:an object containning image information
type rgb24:str or numpy.ndarray or seq< seq<element> >
param width:image width. MUST be given if rgb24 is a string or if it is a numpy.ndarray with ndims != 3. Otherwise it is calculated internally.
type width:int
param height:image height. MUST be given if rgb24 is a string or if it is a numpy.ndarray with ndims != 3. Otherwise it is calculated internally.
type height:int
param quality:Quality of JPEG (0=poor quality 100=max quality) (default is 100.0)
type quality:float

Note

When numpy.ndarray is given:

  • rgb24 MUST be CONTIGUOUS, ALIGNED
  • if rgb24.ndims != 3, width and height MUST be given and rgb24.nbytes/3 MUST match width*height
  • if rgb24.ndims == 3, rgb24.itemsize MUST be 1 (typically, rgb24.dtype is one of numpy.dtype.byte, numpy.dtype.ubyte, numpy.dtype.int8 or numpy.dtype.uint8) and shape MUST be (height, width, 3)
Example:

:

def read_myattr(self, attr):
    enc = tango.EncodedAttribute()
    # create an 'image' where each pixel is R=0x01, G=0x01, B=0x01
    arr = numpy.ones((10,10,3), dtype=numpy.uint8)
    enc.encode_jpeg_rgb24(data)
    attr.set_value(enc)
encode_jpeg_rgb32(rgb32, width=0, height=0, quality=100.0)

Encode a 32 bit rgb color image as JPEG format.

param rgb32:an object containning image information
type rgb32:str or numpy.ndarray or seq< seq<element> >
param width:image width. MUST be given if rgb32 is a string or if it is a numpy.ndarray with ndims != 2. Otherwise it is calculated internally.
type width:int
param height:image height. MUST be given if rgb32 is a string or if it is a numpy.ndarray with ndims != 2. Otherwise it is calculated internally.
type height:int

Note

When numpy.ndarray is given:

  • rgb32 MUST be CONTIGUOUS, ALIGNED
  • if rgb32.ndims != 2, width and height MUST be given and rgb32.nbytes/4 MUST match width*height
  • if rgb32.ndims == 2, rgb32.itemsize MUST be 4 (typically, rgb32.dtype is one of numpy.dtype.int32, numpy.dtype.uint32)
Example:

:

def read_myattr(self, attr):
    enc = tango.EncodedAttribute()
    data = numpy.arange(100, dtype=numpy.int32)
    data = numpy.array((data,data,data))
    enc.encode_jpeg_rgb32(data)
    attr.set_value(enc)
encode_rgb24(rgb24, width=0, height=0)

Encode a 24 bit color image (no compression)

param rgb24:an object containning image information
type rgb24:str or numpy.ndarray or seq< seq<element> >
param width:image width. MUST be given if rgb24 is a string or if it is a numpy.ndarray with ndims != 3. Otherwise it is calculated internally.
type width:int
param height:image height. MUST be given if rgb24 is a string or if it is a numpy.ndarray with ndims != 3. Otherwise it is calculated internally.
type height:int

Note

When numpy.ndarray is given:

  • rgb24 MUST be CONTIGUOUS, ALIGNED
  • if rgb24.ndims != 3, width and height MUST be given and rgb24.nbytes/3 MUST match width*height
  • if rgb24.ndims == 3, rgb24.itemsize MUST be 1 (typically, rgb24.dtype is one of numpy.dtype.byte, numpy.dtype.ubyte, numpy.dtype.int8 or numpy.dtype.uint8) and shape MUST be (height, width, 3)
Example:

:

def read_myattr(self, attr):
    enc = tango.EncodedAttribute()
    # create an 'image' where each pixel is R=0x01, G=0x01, B=0x01
    arr = numpy.ones((10,10,3), dtype=numpy.uint8)
    enc.encode_rgb24(data)
    attr.set_value(enc)