Detect edges using the Roberts filter.
::roberts calculates the first derivative of an image and is used as an edge operator. If the following mask describes a part of the image, A B C D the different filter types are defined as follows: 'roberts_max' max(| A - D |,| B - C |) 'gradient_max' max(| A + B - (C + D)|,| A + C - (B + D)|) 'gradient_sum' |A + B - (C + D)| + |A + C - (B + D)| If an overflow occurs the result is clipped. The result of the operator is stored at the pixel with the coordinates of "D".
|
Image (input_object) |
(multichannel-)image(-array) -> Hobject: HImage(Array) ( byte / int2 ) |
| Input image. | |
|
ImageRoberts (output_object) |
(multichannel-)image(-array) -> Hobject * : HImage(Array) ( byte / int2 ) |
| Roberts-filtered result images. | |
|
FilterType (input_control) |
string -> HTuple.char * |
| Filter type. | |
| Default value: 'gradient_sum' | |
| List of values: 'roberts_max', 'gradient_max', 'gradient_sum' | |
read_image(&Image,"fabrik"); roberts(Image,&Roberts,"roberts_max"); threshold(Roberts,&Margin,128.0,255.0);
::roberts returns H_MSG_TRUE if all parameters are correct. If the input is empty the behaviour can be set via ::set_system('no_object_result',<Result>). If necessary, an exception handling is raised.
::edges_image, ::sobel_amp, ::frei_amp, ::kirsch_amp, ::prewitt_amp
::laplace, ::highpass_image, ::bandpass_image
Image filters
