| Operators |
check_difference — Compare two images pixel by pixel.
check_difference(Image, Pattern : Selected : Mode, DiffLowerBound, DiffUpperBound, GrayOffset, AddRow, AddCol : )
check_difference selects from the input image Image those pixels (g_{o} = g_{Image}), whose gray value difference to the corresponding pixels in Pattern is inside (outside) of the interval [DiffLowerBound,DiffUpperBound]. The pixels of Pattern are translated by (AddRow,AddCol) with respect to Image. Let g_{p} be the gray value from Pattern translated by (AddRow,AddCol) with respect to g_{o}.
If the selected mode Mode is 'diff_inside', a pixel g_{o} is selected if
g_o - g_p - GrayOffset < DiffLowerBound or
g_o - g_p - GrayOffset > DiffUpperBound.
This test is performed for all points of the domain (region) of
Image, intersected with the domain of the translated
Pattern. All points fulfilling the above condition are
aggregated in the output region. The two images may be of different
size. Typically, Pattern is smaller than
Image.
Input image.
Comparison image.
Points in which the two images are similar/different.
Mode: return similar or different pixels.
Default value: 'diff_outside'
Suggested values: 'diff_inside', 'diff_outside'
Lower bound of the tolerated gray value difference.
Default value: -5
Suggested values: 0, -1, -2, -3, -5, -7, -10, -12, -15, -17, -20, -25, -30
Typical range of values: -255 ≤ DiffLowerBound ≤ 255 (lin)
Minimum increment: 1
Recommended increment: 2
Restriction: -255 <= DiffLowerBound && DiffLowerBound <= 255
Upper bound of the tolerated gray value difference.
Default value: 5
Suggested values: 0, 1, 2, 3, 5, 7, 10, 12, 15, 17, 20, 25, 30
Typical range of values: -255 ≤ DiffUpperBound ≤ 255 (lin)
Minimum increment: 1
Recommended increment: 2
Restriction: -255 <= DiffUpperBound && DiffUpperBound <= 255
Offset gray value subtracted from the input image.
Default value: 0
Suggested values: -30, -25, -20, -17, -15, -12, -10, -7, -5, -3, -2, -1, 0, 1, 2, 3, 5, 7, 10, 12, 15, 17, 20, 25, 30
Typical range of values: -255 ≤ GrayOffset ≤ 255 (lin)
Minimum increment: 1
Recommended increment: 2
Restriction: -255 <= GrayOffset && GrayOffset <= 255
Row coordinate by which the comparison image is translated.
Default value: 0
Suggested values: -200, -100, -20, -10, 0, 10, 20, 100, 200
Typical range of values: -32000 ≤ AddRow ≤ 32000 (lin)
Minimum increment: 1
Recommended increment: 1
Column coordinate by which the comparison image is translated.
Default value: 0
Suggested values: -200, -100, -20, -10, 0, 10, 20, 100, 200
Typical range of values: -32000 ≤ AddCol ≤ 32000 (lin)
Minimum increment: 1
Recommended increment: 1
Let A be the number of valid pixels. Then the runtime complexity is O(A).
check_difference returns 2 (H_MSG_TRUE) if all parameters are correct. The behavior with respect to the input images and output regions can be determined by setting the values of the flags 'no_object_result', 'empty_region_result', and 'store_empty_region' with set_system. If necessary, an exception is raised.
connection, select_shape, reduce_domain, select_gray, rank_region, dilation1, opening
Foundation
| Operators |