Operator Reference
image_to_memory_block (Operator)
image_to_memory_block — Write an image to a memory block in various graphic formats.
Signature
image_to_memory_block(Image : : Format, FillColor : MemoryBlockHandle)
Description
The operator image_to_memory_block saves the input image
Image to the memory block MemoryBlockHandle in the format
Format. If the domain (region) cannot be saved in the specified
Format (this is the case for 'jpeg'), all pixels outside the region
receive the color defined by FillColor. For gray value images a value
between 0 (black) and 255 (white) must be passed. For RGB
color images the RGB values can be passed directly as a hexadecimal value:
e.g., 0xffff00 for a yellow background (red=255, green=255, blue=0).
The following formats can be set in Format:
- 'jpeg': JPEG format (lossy compression), file extension *.jpg
-
This format can only store images with one channel (gray value image) or three channels (RGB image).
Only images with the pixel type byte are supported for this file format.
Together with the format string the quality value determining the compression rate can be provided. Large values (maximum 100) create a large memory block with high image quality. Small values significantly decrease the image quality and the size of the memory block.
Possible values: 'jpeg', 'jpeg 30', 'jpeg 60'.
Attention: Images stored for being processed later should not be stored in this format due to the loss of information during compression.
- 'png': PNG format (lossless compression), file extension *.png
-
This format can only store images with one channel (gray value image) or three channels (RGB image). The maximal supported image size (width x height) for PNG is , also in HALCON XL.
Images of type byte and uint2 can be stored in PNG format.
Together with the format string, a compression level between 0 and 9 can be specified, where 0 corresponds to no compression and 9 to the best possible compression. Alternatively, the compression can be selected by using string constants.
Possible values: 'png', 'png 7', 'png none', 'png best', 'png fastest'.
If an image with a reduced domain is written, the region is stored as the alpha channel, where the points within the domain are stored as the maximum gray value of the image type and the points outside the domain are stored as the gray value 0. If an image with a full domain is written, no alpha channel is stored.
Execution Information
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Processed without parallelization.
This operator returns a handle. Note that the state of an instance of this handle type may be changed by specific operators even though the handle is used as an input parameter by those operators.
Parameters
Image (input_object) (multichannel-)image → object (byte / direction / cyclic / int1 / complex / int2 / uint2 / vector_field / int4 / int8 / real)
Input image.
Format (input_control) string → (string)
Graphic format.
Default: 'jpeg'
Suggested values: 'jpeg', 'png'
FillColor (input_control) number → (integer / real)
Gray value for pixels not belonging to the image domain (region).
Default: 0
Suggested values: -1, 0, 255, 65280, 16711680
MemoryBlockHandle (output_control) memory_block → (handle)
Memory block handle.
Result
If the parameter values are correct the operator image_to_memory_block
returns the value 2 (
H_MSG_TRUE)
. Otherwise an exception is raised.
Possible Predecessors
Possible Successors
get_memory_block_ptr,
write_memory_block,
serialize_tuple
See also
Module
Foundation