Operator Reference
gen_image1_extern (Operator)
gen_image1_extern — Create an image from a pointer on the pixels with storage management.
Signature
Description
The operator gen_image1_extern creates an image of the size
Width * Height.
The pixels in PixelPointer are stored line-sequentially.
The type of the given pixels
(PixelPointer) must correspond to Type
(see gen_image_const for a more detailed description of the
image types).
Note that how to pass a pointer value depends on the used operator
signature and programming environment. Make sure to pass the
actual memory address where the image data is stored, not the
address of a pointer variable. Care must be taken not to
truncate 64-bit pointers on 64-bit architectures.
The memory for the new image is not newly allocated
by HALCON,
contrary to gen_image1, and thus is not copied either.
This means that the memory space that PixelPointer points
to must be released by deleting the object Image.
This is done by the procedure ClearProc provided by
the caller. This procedure must have the following signature
void ClearProc(void* ptr);
__cdecl calling convention
when deleting Image.
If the memory shall not be released (in the case of
frame grabbers or static memory) a procedure
“without trunk” or the NULL-Pointer can be passed.
Analogous to the parameter PixelPointer the
pointer has to be passed to the procedure depending
on the used operator signature and programming environment.
Attention
gen_image1_extern does not check if enough memory for an image of
Width * Height is allocated in
PixelPointer.
Also, gen_image1_extern does not check whether the
PixelPointer is valid or not.
Thus, it must be ensured by the user that it is valid.
Otherwise, the program may crash!
Execution Information
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Processed without parallelization.
Parameters
Image (output_object) image → object (byte / direction / cyclic / int1 / int2 / uint2 / int4 / real)
Created HALCON image.
Type (input_control) string → (string)
Pixel type.
Default: 'byte'
List of values: 'byte', 'cyclic', 'direction', 'int1', 'int2', 'int4', 'real', 'uint2'
Width (input_control) extent.x → (integer)
Width of image.
Default: 512
Suggested values: 128, 256, 512, 1024
Value range:
1
≤
Width
(lin)
Minimum increment: 1
Recommended increment: 10
Height (input_control) extent.y → (integer)
Height of image.
Default: 512
Suggested values: 128, 256, 512, 1024
Value range:
1
≤
Height
(lin)
Minimum increment: 1
Recommended increment: 10
PixelPointer (input_control) pointer → (integer)
Pointer to the first gray value.
ClearProc (input_control) pointer → (integer)
Pointer to the procedure re-releasing the memory of the image when deleting the object.
Default: 0
Example (C)
void NewImage(Hobject *new)
{
unsigned char *image;
int r,c;
image = malloc(640*480);
for (r=0; r<480; r++)
for (c=0; c<640; c++)
image[r*640+c] = c % 255;
gen_image1_extern(new,"byte",640,480,(Hlong)image,(Hlong)free);
}
Result
The operator gen_image1_extern returns the value 2 (
H_MSG_TRUE)
if the parameter values are correct.
Otherwise an exception is raised.
Alternatives
gen_image1,
gen_image_const,
get_image_pointer1,
gen_image3_extern
See also
reduce_domain,
paint_gray,
paint_region,
set_grayval
Module
Foundation