Canon CHDK User Manual page 21

Edge overlay
Enable edge overlay
Creates and overlays a high-contrast outline of the edges in a scene.
With the default CHDK settings the Edge overlay will be visible while
the shutter button is half-pressed. Once a picture is taken, the
overlay will be frozen and it will not update until a second picture is
taken, allowing you to align image features in the new shot to the
previous one. During that time you can use the camera's Directional
buttons
–
picture
Up, Down, Left,
See: Edge overlay notes -
Zebra mode should be disabled when using the Edge overlay, and disable Edge overlay when using
Canon Stitch Assist mode.
Filter edges
< Edge overlay < Main Menu
This option applies noise filtering to the edge overlay. It makes the overlay redraw slower but cleans
the overlay of noise that appears in low-light scenes. To reduce overhead of Edge overlay, use 'Filter
edges' only when required.
Panorama Mode
When this option is not set to Off, the edge overlay will not update continuously, but only when
images are taken. Except for the very first image, you will always see the overlay of the previous
image in frozen mode.
Note: Panorama mode returns to Off on each camera startup.
Off -
Does not lock the overlay and it will keep updating.
When set to either Right, Down, Left or Up
opposite direction by the amount corresponding to the "Pano overlap (%)" setting. This is useful so
that you can align the next image of a panorama series in the corresponding directions.
Free -
The overlay will not update continuously, and it will not be moved automatically in any direction,
(it will be centered), however, you can use the Directional buttons –
move it manually.
Pano overlap (%)
Set the overlay offset for Panorama mode, affects each of the options in Panorama mode except
"Free".
Enable [•] / Disable [ ]
Always show
When enabled, the Edge overlay will be visible even without half-pressing the shutter button.
Edge overlay threshold
This setting adjusts the Edge-overlay sensitivity. Lower values create edges along lower contrast /
lower-brightness edges, but can potentially cause more noise. Higher values create edges only on the
highest contrast/ brightest boundaries, and therefore fewer, finer, and more well defined lines. The
downside of using higher values is that some edges might be missed. In general, lower values are more
useful with low-light scenes, while higher values are more useful with bright scenes. If you get too
much noise, try the Filter edges option.
< Main Menu
Enable [•] / Disable [ ]
in -mode to move the overlay of the previous
ALT
or
Right.
Page 53 , for further description and instructions.
.
[ Off, Right, Down, Left, Up, Free ]
" "
is shown in the OSD.
FROZEN
[ 0 - 100]
[ 0 - 255 ]
,
the camera will automatically move the overlay in the
< Edge overlay < Main Menu
19
in -mode to
ALT