Advertisement
CNTNEW is a constant defined in the template as $C8. The CNTNEW command counts pixels or edges
between pixels Begin and End, inclusive. Begin and End can range from 1 to 255, and Begin should
be less than or equal to End. (Remember that binary pixel locations are one-based, not zero-based. The
first pixel is pixel #1.)
CNTNXT ($C0) counts pixels or edges between the current internal Left and Right limits, whatever they
might be. These limits are set by the following actions, whichever occurred most recently:
Any acquire command, which resets Left to 1 and Right to 255.
•
Any CNTNEW command. Left ends up at Begin; Right, at End.
•
A FNDNEW command. Left is initialized to Begin; Right, to End.
•
Any FNDNEW or FNDNXT command, wherein Left is moved to the found pixel or edge
•
(searching forward), or Right is moved to the found pixel or edge (searching backward). If the
desired feature is not found, Left will equal Right + 1, causing further counts and finds to return
zero.
The modifiers that can be used with (i.e. ORed to) CNTNEW or CNTNXT are:
When DRKPIX or BRTPIX is selected, the command counts either dark pixels or bright pixels,
depending on which modifier is used. Here's an example:
OWOUT owio, 0, [CNTNEW|DRKPIX, 32, 64]
GOSUB Ready
This will count all the dark pixels between locations 32 and 64, inclusive. Suppose the binary pixel array
looked like this, where vertical bars represent the location 32 and 64 boundaries:
... 0000111000
In this case, there would be twelve dark pixels counted, and a 12 would be written at the next available
byte location in the results buffer. Assuming that this CNTNEW was the first command after an image
acquisition, that would be location RESULTS + 5 ($25), so we could read the result into the Byte
variable dark_count with the following code:
OWOUT owio, 0, [DUMPADR, RESULTS + 5]
OWIN owio, 2, [dark_count]
Once this sequence of code has executed, remember, the results buffer pointer is reset to RESULTS
($20), and the next result computed will be buffered there. This is due to the reset sent at the end of
the OWIN statement.
© Bueno Systems, Inc. • TSL1401-DB (2009.10.01)
CNTNEW|Modifiers, Begin, End
CNTNXT|Modifiers
Name
Value
DRKPIX
$00
Count dark pixels.
BRTPIX
$02
Count bright pixels.
DRKEDG
$03
Count dark (high-to-low) edges.
BRTEDG
$01
Count bright (low-to-high) edges.
11111111000000001111110000111111
31 32
Description
1111100000 ...
64 65
Page 34 of 52
Advertisement
