Non-Interactive Processes¶

Purpose and expected result¶

This page is the reference for actions that run immediately from Image or Process without a parameter window, plus the Sequence actions that hand off to a dedicated dialog. Use it to answer three questions before clicking: whether the active view is eligible, whether the source is changed, and what happens to precision and metadata.

Most entries start a background job. A still-image extraction or precision conversion opens a new view and leaves the source unchanged. Fast geometry, grayscale/RGB conversion, and Negative Transformation replace the active view's current data. Sequence extraction and precision conversion create new temporary sequences; fast geometry, grayscale/RGB, and negative replace the active sequence with a processed temporary sequence. Save any result that must outlive the session.

At a glance¶

Item	Current behavior
Menu path	Image > Actions, Image > Extract Channel, Image > Convert Format, Image > Fast Geometry, Image > Mask, Image > Sequence, and Process > Adjustments
Enabled when	An active view contains an image. Color-component extraction and Convert to Grayscale require RGB; Convert to RGB requires monochrome. Sequence-only actions require a sequence. Registry launch guards can also reject a busy or incompatible view.
Inputs	Active still image or sequence; an optional assigned mask for Negative Transformation; a second compatible image view when selecting a mask
Outputs	New still/sequence views for duplication, frame/channel extraction, and precision conversion; replacement view data for geometry, grayscale/RGB, negative, and sequence-container conversion; mask association/display-state changes; dialog/file output for Extract Sequence and Export
Recommended image state	Channel extraction and precision conversion are data-management operations. Negative is a nonlinear inversion. Grayscale and perceptual color-space components should be chosen according to the intended workflow, not as a substitute for calibration. Geometry is valid in either state but invalidates WCS/SIP.
Preview support	None. Selecting a reachable immediate action starts it; use Duplicate when a reversible comparison is needed.
Sequence support	Yes, where identified below. Sequence jobs process every frame and show progress; the current Extract Frame action produces one still.
Mask support	Negative Transformation honors the active mask. Mask-menu actions manage the association and display state. Channel extraction, precision conversion, geometry, grayscale/RGB, duplication, frame extraction, and container conversion do not blend through the active mask.
External dependencies	None beyond AfterNight's built-in engine and codecs. Export and Extract Sequence use their separately documented dialogs.

Before you start¶

Select the intended view immediately before choosing an action; every action resolves the current active view.
Save important work before an in-place/replacement operation. Image History records successful processing steps, but temporary sequence backing files are session artifacts rather than durable exports.
Check the view type. The whole Image > Sequence menu is disabled for a still. Color extraction and Convert to Grayscale are disabled for monochrome; Convert to RGB is disabled for RGB.
Expect all Fast Geometry actions to remove the WCS/SIP solution and the header cards because the pixel coordinate system changes.

Procedure¶

Activate the source view and open the submenu named in the matrix.
Confirm that the exact action is enabled. A disabled item indicates an incompatible color, pixel, sequence, or mask state; it is not a preview state.
For an output-producing immediate action, select it once. Sequence jobs show a progress dialog; still-image jobs may complete without one.
Wait for the new view or the active-view update. Do not start another exclusive sequence operation while the view is locked.
Verify the new view name, dimensions, channel count, pixel type, and Image History entry. For geometry, also confirm that WCS/SIP is no longer present.
Save or export the result if it must persist beyond the current session.

Complete parameter and action reference¶

There are no numeric parameters or persisted presets. “Registered” means the menu action is dispatched through ProcessRegistryBuiltins; “direct” means MenuActionManager connects it directly to a coordinator. The following tables cover all 67 reachable actions in this family and the one declared-but-unreachable Automatic MTF action.

This canonical inventory supplies the frozen-template fields; the grouped matrices immediately below supply each action's exact route, output, precision, metadata, and state consequences.

UI label/action	Type and unit	Runtime default	Persisted-default exception	Valid values, step, or constraints	Effect of increasing, decreasing, or selecting	Dependencies and enable/visibility rules	Quality, artifact, runtime, memory, or disk trade-off	Scope: preview/apply, channel, mask, still/sequence	Persistence
Duplicate	Immediate action	N/A	None	Active view	See grouped matrix	Active image	See grouped matrix	Full still/sequence	New view/history
Extract Red Channel	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	One output	R; still/sequence	New view/sequence
Extract Green Channel	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	One output	G; still/sequence	New view/sequence
Extract Blue Channel	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	One output	B; still/sequence	New view/sequence
Extract RGB Channels	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Three outputs	RGB; still/sequence	Three views/sequences
Extract CIE L*	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	L*; still/sequence	New view/sequence
Extract CIE a*	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	a*; still/sequence	New view/sequence
Extract CIE b*	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	b*; still/sequence	New view/sequence
Extract CIE c*	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	c*; still/sequence	New view/sequence
Extract CIE h*	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	h*; still/sequence	New view/sequence
Extract CIE a=R / b=G	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	One encoded output	a/b; still/sequence	New view/sequence
Extract CIE Lab*	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Three outputs	Lab; still/sequence	Three views/sequences
Extract CIE Lch*	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Three outputs	LCh; still/sequence	Three views/sequences
Extract CIE X	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	X; still/sequence	New view/sequence
Extract CIE Y	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	Y; still/sequence	New view/sequence
Extract CIE Z	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	Z; still/sequence	New view/sequence
Extract CIE XYZ	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Three outputs	XYZ; still/sequence	Three views/sequences
Extract HSL Hue	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	H; still/sequence	New view/sequence
Extract HSL Saturation	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	S; still/sequence	New view/sequence
Extract HSL Lightness	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	L; still/sequence	New view/sequence
Extract HSL	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Three outputs	HSL; still/sequence	Three views/sequences
Extract HSV Hue	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	H; still/sequence	New view/sequence
Extract HSV Saturation	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	S; still/sequence	New view/sequence
Extract HSV Value	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	V; still/sequence	New view/sequence
Extract HSV	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Three outputs	HSV; still/sequence	Three views/sequences
Extract HSI Hue	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	H; still/sequence	New view/sequence
Extract HSI Saturation	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	S; still/sequence	New view/sequence
Extract HSI Intensity	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	I; still/sequence	New view/sequence
Extract HSI	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Three outputs	HSI; still/sequence	Three views/sequences
Extract YCbCr Luma	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	Y; still/sequence	New view/sequence
Extract YCbCr Blue Chroma	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	Cb; still/sequence	New view/sequence
Extract YCbCr Red Chroma	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Conversion + output	Cr; still/sequence	New view/sequence
Extract YCbCr	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Three outputs	YCbCr; still/sequence	Three views/sequences
Convert to RGB	Immediate action	N/A	None	Monochrome	See grouped matrix	Mono only	Triples samples	Full still/sequence	Replaces view/history
Convert to Grayscale	Immediate action	N/A	None	RGB	See grouped matrix	RGB only	Reduces samples	Full still/sequence	Replaces view/history
Negative Transformation	Immediate action	N/A	None	Active image	See grouped matrix	Active image	Full transform	Still/sequence; mask-aware	Replaces view/history
Automatic MTF Transform	Unavailable action	N/A	None	No route	No effect	Not connected	None	Unavailable	None
Convert to 8 bit	Immediate action	N/A	None	Different type	See grouped matrix	Active image	Quantization	Full still/sequence	New view/sequence
Convert to signed 16 bit	Immediate action	N/A	None	Different type	See grouped matrix	Not SER/video	Range conversion	Full still/sequence	New view/sequence
Convert to unsigned 16 bit	Immediate action	N/A	None	Different type	See grouped matrix	Active image	Range conversion	Full still/sequence	New view/sequence
Convert to signed 32 bit	Immediate action	N/A	None	Different type	See grouped matrix	Not SER/video	Range conversion	Full still/sequence	New view/sequence
Convert to unsigned 32 bit	Immediate action	N/A	None	Different type	See grouped matrix	Not SER/video	Range conversion	Full still/sequence	New view/sequence
Convert to 32 bit float	Immediate action	N/A	None	Different type	See grouped matrix	Not SER/video	More storage	Full still/sequence	New view/sequence
Convert to 64 bit float	Immediate action	N/A	None	Different type	See grouped matrix	Not SER/video	Highest storage	Full still/sequence	New view/sequence
Horizontal Mirror	Immediate action	N/A	None	Active image	See grouped matrix	Active image	Strips WCS/SIP and cards	Full still/sequence	Replaces view/history
Vertical Mirror	Immediate action	N/A	None	Active image	See grouped matrix	Active image	Strips WCS/SIP and cards	Full still/sequence	Replaces view/history
Rotate 180º	Immediate action	N/A	None	Active image	See grouped matrix	Active image	Strips WCS/SIP and cards	Full still/sequence	Replaces view/history
Rotate 90º Left	Immediate action	N/A	None	Active image	See grouped matrix	Active image	Swaps dimensions; WCS/SIP and cards lost	Full still/sequence	Replaces view/history
Rotate 90º Right	Immediate action	N/A	None	Active image	See grouped matrix	Active image	Swaps dimensions; WCS/SIP and cards lost	Full still/sequence	Replaces view/history
Convert to SER	Sequence action	N/A	None	Non-SER sequence	See grouped matrix	Sequence only	Codec limits/full disk output	Full sequence	Temporary replacement
Convert to Image List	Sequence action	N/A	None	Non-list sequence	See grouped matrix	Sequence only	Full disk output	Full sequence	Temporary replacement
Convert to FITS	Unavailable action	N/A	None	Disabled	No effect	Sequence state disables	None	Unavailable	None
Extract Frame	Sequence action	N/A	None	Sequence	See grouped matrix	Sequence only	One still allocation	Current frame	New still/history
Extract Sequence	Dialog action	UI state	Dialog lifecycle	Sequence	Opens dialog	Sequence only	Selected disk output	Full sequence dialog	User-selected output
Export...	Dialog action	UI state	Export lifecycle	Sequence	Opens dialog	Sequence only	Codec-dependent	Full sequence dialog	User-selected files
Select Mask	Dialog action	View state	View only	Compatible mask	Opens selector	Active image	No pixel rewrite	Mask association	Session state
Remove Mask	Immediate action	View state	View only	Attached mask	Detaches mask	Masked image	No pixel rewrite	Mask association	Session state
Invert Mask	Checked action	View state	View only	Boolean	Toggles interpretation	Masked image	No pixel rewrite	Mask state	Session state
Enable Mask	Checked action	View state	View only	Boolean	Toggles use	Masked image	No pixel rewrite	Mask state	Session state
Show Mask	Checked action	View state	View only	Boolean	Toggles visibility	Masked image	Display only	Mask display	Session state
Overlay Red	Exclusive action	View mode	View only	Eight modes	Selects mode	Masked image	Display only	Mask display	Session state
Overlay Green	Exclusive action	View mode	View only	Eight modes	Selects mode	Masked image	Display only	Mask display	Session state
Overlay Blue	Exclusive action	View mode	View only	Eight modes	Selects mode	Masked image	Display only	Mask display	Session state
Overlay Yellow	Exclusive action	View mode	View only	Eight modes	Selects mode	Masked image	Display only	Mask display	Session state
Overlay Magenta	Exclusive action	View mode	View only	Eight modes	Selects mode	Masked image	Display only	Mask display	Session state
Overlay Cyan	Exclusive action	View mode	View only	Eight modes	Selects mode	Masked image	Display only	Mask display	Session state
Replace	Exclusive action	View mode	View only	Eight modes	Selects mode	Masked image	Display only	Mask display	Session state
Multiply	Exclusive action	View mode	View only	Eight modes	Selects mode	Masked image	Display only	Mask display	Session state

View, channel, and color-space actions¶

UI label/action	Menu path and wiring	Enabled when	Output and source effect	Precision and metadata consequence
Duplicate	Image > Actions; direct	Active image	Still: new deep-copy view. Sequence: new view reopened from the same backing sequence file. Source unchanged.	Still keeps image metadata and astrometry/star profile but clears disk-file identity and filename. Sequence preserves the auto-debayer and pending-change flags; reopening the backing file is not an independent disk copy.
Extract Red Channel	Image > Extract Channel; registered	RGB	One new monochrome R view/sequence; source unchanged.	Keeps source pixel type and dimensions; copied sample values are independent. Metadata is copied by channel extraction.
Extract Green Channel	Same; registered	RGB	One new monochrome G view/sequence; source unchanged.	Same as Red.
Extract Blue Channel	Same; registered	RGB	One new monochrome B view/sequence; source unchanged.	Same as Red.
Extract RGB Channels	Same; registered	RGB	Three new monochrome R, G, and B views/sequences; source unchanged.	Same source pixel type and dimensions for all three; metadata copied.
Extract CIE L*	Same; registered	RGB	One L* component view/sequence.	RGB is read as fractions of full scale - linear when the image says so, sRGB-encoded otherwise - and converted to CIE Lab; L is a 32-bit floating image (64-bit for a 64-bit source) in the unit interval, whatever the source's pixel type. The component keeps the acquisition record and the WCS/SIP solution and drops the header cards, for a still and a sequence frame alike.
Extract CIE a*	Same; registered	RGB	One a* component view/sequence.	Same Lab conversion, floating encoding, and metadata behavior as CIE L*.
Extract CIE b*	Same; registered	RGB	One b* component view/sequence.	Same Lab conversion, floating encoding, and metadata behavior as CIE L*.
Extract CIE c*	Same; registered	RGB	One LCh chroma component view/sequence.	RGB→Lab→LCh with the same floating encoding and metadata behavior as CIE L*.
Extract CIE h*	Same; registered	RGB	One LCh hue component view/sequence.	Hue is a fraction of a turn in the unit interval, not an angle in degrees; same floating encoding and metadata behavior as CIE L*.
Extract CIE a=R / b=G	Same; registered	RGB	One three-channel view/sequence with a* in R, b* in G, and B cleared.	A floating colour image of a* and b* as CIE L* encodes them, blue cleared; this is a visualization/transport encoding, not an RGB color image. Metadata as CIE L*.
Extract CIE Lab*	Same; registered	RGB	Three monochrome L, a, and b* outputs.	Three floating components, each as CIE L* encodes and describes it.
Extract CIE Lch*	Same; registered	RGB	Three monochrome L, c, and h* outputs.	Three floating components, each as CIE L* encodes and describes it.
Extract CIE X	Same; registered	RGB	One CIE X component output.	Engine RGB→XYZ conversion, each tristimulus value divided by the white's so the white is one; floating encoding and metadata as CIE L*.
Extract CIE Y	Same; registered	RGB	One CIE Y component output.	Same conversion, precision, and metadata behavior as CIE X.
Extract CIE Z	Same; registered	RGB	One CIE Z component output.	Same conversion, precision, and metadata behavior as CIE X.
Extract CIE XYZ	Same; registered	RGB	Three monochrome X, Y, and Z outputs.	Same floating encoding and component metadata behavior for all outputs.
Extract HSL Hue	Same; registered	RGB	One HSL hue output.	Component is a 32-bit floating plane in the unit interval, 64-bit for a 64-bit source; metadata as CIE L*.
Extract HSL Saturation	Same; registered	RGB	One HSL saturation output.	Same floating encoding and metadata behavior as HSL Hue.
Extract HSL Lightness	Same; registered	RGB	One HSL lightness output.	Same floating encoding and metadata behavior as HSL Hue.
Extract HSL	Same; registered	RGB	Three monochrome H, S, and L outputs.	Same floating encoding and component metadata behavior for all outputs.
Extract HSV Hue	Same; registered	RGB	One HSV hue output.	Component is a 32-bit floating plane in the unit interval, 64-bit for a 64-bit source; metadata as CIE L*.
Extract HSV Saturation	Same; registered	RGB	One HSV saturation output.	Same floating encoding and metadata behavior as HSV Hue.
Extract HSV Value	Same; registered	RGB	One HSV value output.	Same floating encoding and metadata behavior as HSV Hue.
Extract HSV	Same; registered	RGB	Three monochrome H, S, and V outputs.	Same floating encoding and component metadata behavior for all outputs.
Extract HSI Hue	Same; registered	RGB	One HSI hue output.	Component is a 32-bit floating plane in the unit interval, 64-bit for a 64-bit source; metadata as CIE L*.
Extract HSI Saturation	Same; registered	RGB	One HSI saturation output.	Same floating encoding and metadata behavior as HSI Hue.
Extract HSI Intensity	Same; registered	RGB	One HSI intensity output.	Same floating encoding and metadata behavior as HSI Hue.
Extract HSI	Same; registered	RGB	Three monochrome H, S, and I outputs.	Same floating encoding and component metadata behavior for all outputs.
Extract YCbCr Luma	Same; registered	RGB	One Y (luma) output.	Component is a 32-bit floating plane in the unit interval, 64-bit for a 64-bit source; metadata as CIE L*.
Extract YCbCr Blue Chroma	Same; registered	RGB	One Cb output.	Same floating encoding and metadata behavior as YCbCr Luma.
Extract YCbCr Red Chroma	Same; registered	RGB	One Cr output.	Same floating encoding and metadata behavior as YCbCr Luma.
Extract YCbCr	Same; registered	RGB	Three monochrome Y, Cb, and Cr outputs.	Same floating encoding and component metadata behavior for all outputs.
Convert to RGB	Process > Adjustments; direct	Monochrome	Replaces the active still/sequence with three identical channels.	Pixel type is unchanged. The result keeps the image's acquisition record, WCS/SIP solution, header cards and processing state; an explicit validity mask is shared by the three channels. CFA sequences may be auto-debayered first when that view option is enabled.
Convert to Grayscale	Same; direct	RGB	Replaces the active still/sequence with one channel, using `0.2989R + 0.5870G + 0.1140B`.	Pixel type is unchanged; the weighted sum is rounded to the nearest code. The result keeps the image's acquisition record, WCS/SIP solution, header cards and processing state.
Negative Transformation	Same; direct	Active image	Replaces each selected sample with its complement: one minus a floating sample, the pixel-type maximum minus an unsigned one, and the sum of the minimum and maximum minus a signed one. Still/sequence data changes.	Pixel type, dimensions, and metadata are retained; a CFA sequence may become RGB first when auto-debayer is enabled. Active-mask blending is supported. The history state is marked nonlinear.
Automatic MTF Transform	Declared action only; no menu insertion, registry descriptor, or connection	Never reachable in the current UI	No runnable action.	No current precision or metadata consequence. Do not confuse the display auto-stretch with a committed Automatic MTF process.

For sequence channel extraction, the sequence processor requests CFA debayering before RGB/component extraction. Still-image extraction uses the already displayed RGB data. Color-space component images are normalized encodings for processing and inspection; they do not carry a unit such as degrees in their stored sample values. A component is a 32-bit floating image whatever the source's pixel type, so a 16-bit image's lightness is not rounded to 16-bit codes. A sequence conversion, unlike an extraction, keeps a mosaic frame as a mosaic.

Pixel-type conversion actions¶

UI label/action	Menu path and wiring	Enabled when	Output and source effect	Precision and metadata consequence
Convert to 8 bit	Image > Convert Format; registered	Active type is not 8-bit	New view/sequence; source unchanged.	Normalizes the source type to unsigned 8-bit. Metadata is copied. Quantization is irreversible.
Convert to signed 16 bit	Same; registered	Active type differs; disabled for SER/video sequences	New signed-16 view/sequence; source unchanged.	Normalized range conversion; metadata copied.
Convert to unsigned 16 bit	Same; registered	Active type differs	New unsigned-16 view/sequence; source unchanged.	Normalized range conversion; metadata copied. SER-compatible high-precision integer choice.
Convert to signed 32 bit	Same; registered	Active type differs; disabled for SER/video sequences	New signed-32 view/sequence; source unchanged.	Normalized range conversion; metadata copied.
Convert to unsigned 32 bit	Same; registered	Active type differs; disabled for SER/video sequences	New unsigned-32 view/sequence; source unchanged.	Normalized range conversion; metadata copied.
Convert to 32 bit float	Same; registered	Active type differs; disabled for SER/video sequences	New float32 view/sequence; source unchanged.	Normalized sample values are represented in `[0,1]`; metadata copied. Avoids integer quantization but cannot restore detail already lost.
Convert to 64 bit float	Same; registered	Active type differs; disabled for SER/video sequences	New float64 view/sequence; source unchanged.	Normalized sample values are represented in `[0,1]`; metadata copied. Doubles storage relative to float32 without creating new source precision.

The generic conversion path maps a source sample through its normalized range and then into the destination range. For signed integer types, the full signed range maps to [0,1]; floating-point storage already uses normalized samples. The mapping is computed in double precision and rounded to the nearest code. Converting to fewer integer levels quantizes values, while converting to a wider type only provides headroom for later processing. Converting to the image's own type makes an exact copy. A sequence conversion to a type its container cannot store - a SER beyond 16-bit unsigned, a video beyond 8-bit - is refused by name; use Convert to Image List first.

Fast Geometry actions¶

UI label/action	Menu path and wiring	Enabled when	Output and source effect	Precision and metadata consequence
Horizontal Mirror	Image > Fast Geometry; direct	Active image	Reverses each row. A still image is the view's own edit; a sequence is replaced by a new temporary sequence with every frame mirrored. History: Image Horizontal Mirror for a still, Sequence Horizontal Mirror for a sequence.	Every sample is copied exactly, in every pixel type; channels kept. The acquisition record and the image's meaning are kept; the WCS/SIP solution is invalidated, the header cards are dropped and any output decision is withdrawn.
Vertical Mirror	Same; direct	Active image	Reverses row order. History: Image Vertical Mirror / Sequence Vertical Mirror.	Same as Horizontal Mirror.
Rotate 180º	Same; direct	Active image	Reverses both axes; width/height unchanged. History: Image Rotation / Sequence Rotation, described "180 degrees".	Same as Horizontal Mirror.
Rotate 90º Left	Same; direct	Active image	Turns a quarter turn counter-clockwise; width and height swap. History: Image Rotation / Sequence Rotation, described "90 degrees left".	Same as Horizontal Mirror; a non-square pixel aspect is inverted with the axes.
Rotate 90º Right	Same; direct	Active image	Turns a quarter turn clockwise; width and height swap. History: Image Rotation / Sequence Rotation, described "90 degrees right".	Same as Rotate 90º Left.

A still image's mirror or turn is an edit of its view: it is computed on a worker, recorded as one Image History step before the view shows it, and undone by that step. Edits of one view run one at a time in the order they were asked for, so pressing a turn twice turns twice. When the image had a solution, the Session Console notes that it was removed and that a plate solve restores it.

Over a sequence, the action takes the view, turns or mirrors every frame of the sequence as recorded, writes the frames into a new sequence of the same container in the session's temporary directory, and shows it in the view as one history step once the whole sequence is written. A progress window titled Flip sequence (mirrors) or Sequence Rotation (turns) shows the frames done, and its Cancel stops the run, leaving the view as it was and nothing in the temporary directory. A mosaic frame is turned without being demosaiced: its filter pattern is restated so each sample stays under the filter it was measured through, and the view still demosaics the frames for display when it did before. If another run already holds the sequence, a warning titled Rotate Sequence says "Another process is executing for this sequence, please cancel that job first before running this process" and nothing changes. A sequence run that cannot finish says why in a message titled as its progress window, "Could not turn the sequence 'name': ...", and in the Session Console.

Each mirror and turn moves an explicit validity mask with its samples; any other validity rule is kept as stated. Nothing is interpolated: every sample is copied exactly. A turn drops the header cards with the solution, as every geometry change does.

Sequence actions¶

UI label/action	Menu path and wiring	Enabled when	Output and source effect	Precision and metadata consequence
Convert to SER	Image > Sequence > Convert; registered	Sequence that is not already SER	Replaces the active view with a new temporary SER sequence; original backing input is not overwritten.	Frames are constrained to SER-supported mono/RGB 8- or 16-bit storage; higher/signed/float inputs are converted to unsigned 16-bit. Per-frame metadata is not a general SER payload. FPS is copied before destination finalization.
Convert to Image List	Same; registered	Sequence that is not already an image list	Replaces the active view with a temporary image-list sequence; original input is not overwritten.	Writes a list of frame files through the image-list/FITS path, preserving the processed image type and frame metadata supported by the codec. FPS is copied before finalization.
Convert to FITS	Same; registered	Disabled by current action-state code for every sequence	No reachable output. If reached, the coordinator converts nothing and reports “Converting to a FITS sequence is not available. Convert to Image List writes every frame of the sequence as a FITS file.” for every sequence.	No current precision or metadata consequence; use Convert to Image List when FITS frame files are required.
Extract Frame	Image > Sequence; registered non-interactive	Sequence	Copies the currently displayed frame into one new still named with `FRAME_<current frame>`; sequence unchanged.	Pixel type, pixels, and copied image metadata are retained in the new view.
Extract Sequence	Image > Sequence; registered single-image dialog	Sequence	Opens the contiguous-range extraction dialog and writes a new sequence in the source's own container: SER, an Image List (`.anseq`), AVI, MP4, or Matroska (`.mkv`) for any other video.	See Extract Sequence for inclusive range semantics, metadata, FPS, cancellation, and cleanup.
Export...	Image > Sequence; registered image operation	Sequence	Opens the Export Sequence dialog; it is not immediate after the dialog opens.	Output codec determines precision and metadata. See Saving and Exporting.

Convert to SER/Image List processes every frame without applying the view's CFA auto-debayer option. Both jobs reject converting to the sequence's existing type, lock the source view, clean incomplete temporary output on failure/cancellation, and publish the replacement only after successful finalization.

Mask actions¶

UI label/action	Menu path and wiring	Enabled when	Output and source effect	Precision and metadata consequence
Select Mask	Image > Mask; registered single-image	Active image	Opens the mask selector and associates a compatible image chosen there.	Does not alter target samples or metadata. Compatibility and mask behavior are covered in Masks.
Remove Mask	Same; registered single-image	Active image with a mask	Removes the association.	Target and mask samples/metadata are unchanged.
Invert Mask	Same; direct checked action	Active image with a mask	Toggles interpretation of mask weights.	Display/process state only; no sample or metadata rewrite.
Enable Mask	Same; direct checked action	Active image with a mask	Enables/disables the mask for mask-aware processing.	State only; disabling does not detach the mask.
Show Mask	Same; direct checked action	Active image with a mask	Shows/hides mask rendering over the target.	Display state only.
Overlay Red	Image > Mask > Rendering Mode; direct checked action	Active image with a mask	Selects red overlay.	Display state only; mutually exclusive with the other seven rendering modes.
Overlay Green	Same; direct checked action	Active image with a mask	Selects green overlay.	Display state only; mutually exclusive.
Overlay Blue	Same; direct checked action	Active image with a mask	Selects blue overlay.	Display state only; mutually exclusive.
Overlay Yellow	Same; direct checked action	Active image with a mask	Selects yellow overlay.	Display state only; mutually exclusive.
Overlay Magenta	Same; direct checked action	Active image with a mask	Selects magenta overlay.	Display state only; mutually exclusive.
Overlay Cyan	Same; direct checked action	Active image with a mask	Selects cyan overlay.	Display state only; mutually exclusive.
Replace	Same; direct checked action	Active image with a mask	Displays the mask in replace mode.	Display state only; mutually exclusive.
Multiply	Same; direct checked action	Active image with a mask	Displays target multiplied by the mask.	Display state only; mutually exclusive.

How the algorithm works¶

Conceptual pipeline¶

Menu/action-state code checks the active view, image/color/sequence type, mask association, and registry launch guard.
The action either changes lightweight mask state immediately or starts a detached worker. Sequence workers acquire an exclusive view lock and create a temporary destination when output frames are required.
Engine code copies/extracts channels, converts color or sample ranges, reindexes geometry, or applies the negative transform. Most jobs run their per-pixel/per-frame loops in parallel inside the engine.
A successful job creates a new view or publishes replacement data, adds Image History, refreshes the display, releases the lock, and closes progress.

Model and equations¶

Type conversion uses normalized intensity n. Unsigned integer samples use n = x / max(T); signed integer samples map the complete signed range to [0,1]; float and double samples already represent n. The destination is the corresponding denormalization into its range, computed in double precision. Integer destinations round to the nearest of a finite set of codes.

Grayscale conversion is:

Y = 0.2989 R + 0.5870 G + 0.1140 B

with the result rounded to the nearest code of the unchanged pixel type. Convert to RGB sets R = G = B = Y. Negative Transformation is the complement in normalized units: y = 1 - x for a floating sample, y = max(T) - x for an unsigned type and y = min(T) + max(T) - x for a signed one (-1 - x for 16 bits), for every processed sample of pixel type T, with the normal active-mask blend applied afterward. Mirrors and right-angle rotations only move samples, each destination sample one source sample copied bit for bit; they do not interpolate.

Boundary and failure behavior¶

Registry guards reject a missing active image, incompatible launch state, or a view already occupied by an exclusive process. Sequence jobs separately warn when their view lock cannot be acquired.
Sequence progress can cancel engine processing. Every job that cannot finish - an engine refusal, an image of the wrong kind, a view that cannot be opened, a sequence that cannot be read or written - says why in a message titled as the action and in the Session Console, and leaves no temporary output; only a cancellation is quiet.
Type-conversion functions assume normal engine sample ranges. Reducing bit depth quantizes; it does not dither. Right-angle geometry has no boundary fill because every source sample maps to exactly one destination sample.
Select Mask shows “No selected image to process” if invoked without a target; Remove Mask is a no-op if no mask is attached.

Parameter interactions and starting points¶

Combination	Conservative starting point	Too weak looks like	Too strong looks like	Adjustment order
Channel extraction + later recombination	Keep the source type; use RGB channels for literal component separation.	Wrong component selected or expected output count missing.	Early 8-bit conversion shows banding/quantization in later edits.	Extract first, inspect names/counts, then convert precision only for a required destination.
Color-space component + integer storage	A component is already float32; convert it to an integer type only for a destination that needs one.	Converting a component to 8 bits collapses subtle edits to the same code.	Float64 increases memory/disk use without recovering source detail.	Choose component, process in float, then convert only at final output.
Geometry + astrometry	Duplicate or save first; plan to plate-solve again.	Coordinates are gone after the turn, and header cards such as exposure or filter are no longer written when the result is saved.	Not applicable; transforms are exact.	Geometry, verify orientation, then obtain a new WCS/SIP solution.
Negative + mask	Verify Enable Mask, Show Mask, and rendering mode before running.	Intended protected/affected region is reversed or unchanged.	Full-strength inversion in the wrong region.	Select mask, inspect/invert state, enable, then run Negative once.
Sequence container conversion	Use Image List for broadly preserved frame type/metadata; use SER for compatible compact video-style data.	Destination is the same type and the action is disabled/rejected.	SER forces unsupported high/signed/float precision to 16-bit unsigned.	Inspect type/channels/FPS, choose destination, wait for finalization, verify first/last frame.

Inputs, outputs, and metadata¶

New still outputs receive generated names such as channel/component suffixes, CONV_*, or FRAME_*; the UI disambiguates duplicate view names. A new view is unsaved until explicitly saved. Still Duplicate clears the source file identity so saving cannot silently overwrite the original.

Raw R/G/B channel extraction and all type-conversion outputs preserve dimensions and copy image metadata, header cards included. A color-space component is a measurement of the image: it keeps the acquisition record and the WCS/SIP solution and drops the header cards, for a still and a sequence frame alike. Grayscale/RGB conversion keeps the image's metadata. Geometry keeps the acquisition record and the image's meaning, invalidates the WCS/SIP solution and drops the header cards. Negative retains metadata because it replaces/redefines pixels in the active image. Mask state actions never rewrite samples or metadata.

Sequence processing uses temporary disk storage. Channel and type conversions open new sequence views and leave the source view unchanged. Geometry, grayscale/RGB, negative, and container conversion update the active view to a new processed sequence while leaving the original backing input file untouched.

Performance¶

Cost is linear in pixel count for a still and approximately linear in frame count × pixels per frame for a sequence. Multi-output component actions write three full outputs. RGB conversion triples monochrome pixel storage; grayscale reduces three channels to one. Float64 uses twice the sample memory and disk of float32, and four times unsigned 16-bit. Temporary sequence operations need enough free space for the complete destination before the view is published.

Prototype a long sequence with Extract Sequence if runtime or storage is uncertain. Do not close the application or remove source media while a detached sequence job is active.

Worked example¶

Evidence mode: Source-and-test-derived.
Input condition/provenance and settings: An RGB sequence with known first and last frames; choose Image > Extract Channel > Extract RGB Channels. No project-owned dataset was executed.
Expected checkpoint: Three new sequence views are created for R, G, and B; each is monochrome, retains the source dimensions/pixel type, and the source sequence remains unchanged. The sequence processor requests CFA debayering before extraction when applicable.
Inspect at 100%/statistics/history: Compare corresponding first/last frames, verify the output pixel type and Image History lineage, and confirm the original RGB sequence is still open.
Limitations: The checkpoint is derived from current source plus focused engine and process-framework tests, not an executed visual dataset; no visual-quality claim is made.

Warnings and limitations¶

Convert to FITS is currently disabled and has no working conversion path.
Automatic MTF Transform is not reachable; display auto-stretch is separate and does not commit pixel data.
Fast Geometry discards WCS/SIP and the header cards; grayscale/RGB conversion keeps the image's metadata. Re-solve geometry-dependent data after a mirror or rotation.
When Image History cannot keep the image a still mirror or turn replaces, the history says so once, in a message titled Image History, and the image and its history are left as they were. A failure of the view's own - the mirror or turn itself could not be computed, or the view could not show a result the history had recorded - leaves the image as it was and is only written to the Session Console; no message is shown. This is a known open defect.
Negative Transformation is nonlinear and destructive to the active view data. Its result depends on mask inversion/enabled state at execution time.
Color-space components are 32-bit floating encodings in the unit interval. Hue and chroma samples are not stored as human-readable degrees or physical units.
Sequence Duplicate reopens the same backing file; it is another view, not a second on-disk copy. Save/export when independent durable data is required.
A failed job says why. If no new output appears and no message was shown, the job was cancelled; inspect the Session Console for the stop.

Troubleshooting¶

Symptom or exact error	Verified cause/validation path	Recovery	Evidence source
Extract Channel is disabled	Active image is not RGB.	Select an RGB view, or use Convert to RGB for a monochrome image before extracting.	`ActionStateCoordinator::setEnableImageColorActions`
A precision-conversion item is disabled	The image already has that type, or the selected SER/video sequence cannot store the requested type.	Inspect the active type; choose a compatible destination or Convert to Image List.	`ActionStateCoordinator::updateActiveImageActions`
Convert to FITS is disabled	Current action-state code always disables it for sequences.	Use Convert to Image List, which writes the supported image-list/FITS frame path.	`ActionStateCoordinator::updateActiveImageActions`; `ImageOperationsCoordinator::convertToFITSSeq`
Coordinates no longer solve after mirror/rotate	The operation intentionally invalidates WCS/SIP and drops the header cards.	Plate-solve the transformed result again.	`ImageViewControl::orientImage`; `orientViewImage`; `ImageTurnsTest`
A still mirror or turn did nothing, with an Image History message	Image History could not keep the image the edit replaces; it says so once and nothing changes.	Free memory or close other views, and retry.	`ImageHistoryTracker.cpp`; `GeometryProcessCase.AnEditTheHistoryCannotKeepIsSaidOnceAndChangesNothing`
A still mirror or turn did nothing and no message appeared	A failure of the view's own: the turn could not be computed, or the view could not show a result the history had recorded; the reason is only in the Session Console.	Read the Session Console, free memory or close other views, and retry.	`ImageViewControl::startNextEdit`
"Another process is executing for this sequence, please cancel that job first before running this process" after a mirror or turn	Another run holds the sequence view.	Wait for or cancel that run, then retry.	`NonInteractiveProcesses.cpp` (`replaceSequence`); `ImageTurnsTest`
“Could NOT extract frame ... because it is not a sequence”	Extract Frame was invoked for a still.	Activate a sequence and navigate to the wanted frame first.	`NonInteractiveProcesses::extractFrame`
“No selected image to process”	A mask action resolved no active view.	Activate the intended target and retry.	`ProcessLauncher::executeSelectMask`; `MaskOverlayCoordinator::activeControlOrNotify`
Rendering mode will not uncheck	The selected mask rendering action is forced checked so exactly one mode remains active.	Select another rendering mode rather than trying to clear the current one.	`MaskOverlayCoordinator::applyOverlayMode`
Sequence job ends with no output	The view lock failed (a warning says so), the job was cancelled, or a failure ended it - which a message titled as the action names.	Wait for other processing, read the message, verify source access and free space, retry on a short extracted sequence, and inspect Session Console.	`NonInteractiveProcesses.cpp`; `ChannelSequenceTest`; `ImageOperationTest`

Extract Sequence documents contiguous-range extraction into a new sequence.
Masks covers mask compatibility, weights, inversion, and how processing consumes the selected mask.
Saving and Exporting covers durable files, codec limits, and the Export Sequence dialog.
Image History covers lineage, undo, and the difference between a new view and a modified active view.
File Formats is the codec capability matrix for choosing SER, FITS/image-list, or another saved format.

References and provenance¶

AfterNight action inventory and exact labels: AfterNightAppUiBuilder.h, MenuActionManager.cpp, ProcessRegistryBuiltins.cpp.
Active-view, type, sequence, and mask availability: ActionStateCoordinator.cpp.
Immediate-operation behavior and temporary-output cleanup: NonInteractiveProcesses.cpp, ProcessCommonUtils.h, ChannelExtractor.cpp, ImageOperationsCoordinator.cpp, and MaskOverlayCoordinator.cpp.
Pixel conversion, grayscale/RGB equations, negative transform, and metadata defaults: ChannelActions.cpp over the engine's ImageConversion.h, SampleConversion.h, ChannelScope.h, ColorTransform.h, Geometry.h and PointwiseProgramBuilder.h.
Sequence-container coercion, FPS finalization, and image-list publication: SequenceContainers.cpp over the engine's SerSequence.h, ImageListManifest.h and SequenceOutput.h.
Verification provenance: the focused GoogleTest sources.