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Saving And Exporting

Export Sequence dialog configured for MP4 and H.264 with CFA debayering, autostretch, resize, dimensions, and fit mode

Sequence Export exposes codec-dependent delivery settings together with CFA, display-stretch, and resize choices before any output is written.

Purpose, audience, prerequisites, and expected result

Saving writes the active still image or sequence to a user-selected path. Sequence Export instead renders every decoded frame into a chosen delivery format and can change frame rate, displayed intensity, and geometry. Use saving for a faithful processing copy in a compatible format; use Export for a deliberately transformed SER, raw AVI, MP4, or WebM handoff.

After a successful save, the destination is added to recent files and, when the view still shows what was written, its pending-changes marker is cleared and the view takes the new file as its source. An edit made while the save ran keeps the changes pending, because the view no longer shows what is in the file. AfterNight performs no automatic readback or checksum verification. After a successful sequence export, a success message appears and the export dialog closes; the active sequence and its pending state are unchanged.

Reachability and availability

Item Current behavior
Path File > Save as... or its toolbar icon; Image > Actions > Save File...; sequence-only Image > Sequence > Export....
Enabled/visible when Both save actions require an active view containing an image. Export requires an active sequence view. There is no separate plain Save action that writes back without prompting.
Supported inputs/state Save handles a still image, native SER, AfterNight image list, or FFmpeg-backed sequence according to the active view. Export handles any active sequence whose frames can be decoded. Masks and display overlays are not composited into still saves.
Outputs/side effects Save creates or replaces one still file, one SER/video file, or an .anseq plus its sibling frame directory. Export creates one SER, raw AVI, MP4, or WebM file. Successful save adds the destination to recent files and, when the view still shows what was written, clears its pending-change marker.
Persistence Save starts in the shared last-open directory and uses General > Default Save Format for a still's initial filter/suffix. Export remembers format, codec, resolution mode, and a separate last directory; it does not remember FPS, autostretch, resize enablement, fill mode, dimensions, or output name.
External dependencies Built-in still/SER/image-list codecs; bundled FFmpeg with the software encoders libx264, libx265 and libvpx-vp9 for video input and H.264/H.265/VP9 output. No network or catalog is required.

Before you start

  • Keep an astronomy-native FITS or XISF master before creating an 8-bit or lossy delivery copy. PNG converts signed, 32-bit integer, and floating data to unsigned 16-bit; JPEG converts every non-8-bit image to unsigned 8-bit.
  • Save a colour filter array mosaic as FITS, XISF, or TIFF, which record the filter array, or demosaic it first. PNG and JPEG cannot record one, and the save refuses them before anything is written. An X-Trans (Fujifilm) mosaic is kept by XISF and TIFF only: FITS states one two-by-two pattern, so a FITS save of one is refused too, the message naming XISF and TIFF.
  • Check the active image's pixel type, linear state, geometry, and metadata. Saving writes underlying image data, not the viewer's autostretch, selected display channel, zoom, grid, star overlay, or mask overlay.
  • A still save is written whole or not at all: the file is written beside the destination and moved into place only when it is complete, so a failed or stopped save leaves an existing destination as it was.
  • For an image-list sequence, reserve space for both the .anseq file and a sibling <name>-frames directory containing FITS frames.
  • Saving a video sequence decodes and re-encodes every frame at 8 bits; it is not a file copy. A video read from .mpg or .mpeg cannot be saved under that suffix, because AfterNight writes no MPEG program stream; choose .mp4, .mkv, .webm or .avi, or use Image > Sequence > Export....

Procedure

Save a still image

  1. Activate the image to save. Choose File > Save as..., press the Save toolbar icon, or choose Image > Actions > Save File.... All three routes run the same workflow; Ctrl+Shift+S is assigned to Save as....
  2. Confirm the proposed view name and folder. Select TIFF, FITS, PNG, XISF, or JPEG and give the file the matching extension. If an extension and selected filter disagree, the extension chooses the engine codec.
  3. If the destination exists, review the file dialog's overwrite confirmation. Accepting it permits replacement; AfterNight does not create a backup.
  4. Confirm the dialog. A Save File progress window appears while a worker writes the image as it was when you confirmed, with the Export settings as they were then. You can keep working meanwhile.
  5. Treat completion as an encode result, not a round-trip guarantee. Reopen the destination, confirm dimensions/channels/pixel type in Image Summary, and inspect FITS/XISF metadata with the relevant metadata viewer before deleting a master or source file.

Save a sequence copy

  1. Activate a sequence and use either save path. The dialog offers the current family's suffix: SER .ser, image list .anseq, and a video its own container suffix. The save reads every frame from the sequence's file and writes it into the container the chosen path names - .ser, .anseq, .avi, .mp4 (or .mov, written as MP4), .mkv or .webm - so a path with another of those suffixes converts the sequence.
  2. Every frame is written as its file holds it, whatever the view shows: a mosaic stays a mosaic in SER and in an image list's frames, and is written as its grey samples to AVI or video. Demosaic through a process first if colour frames are wanted.
  3. Select a new destination and confirm. A copy is written privately and published only when its last frame is in, so a failed or cancelled copy leaves nothing. Image-list copies write each frame as a FITS file with its header cards, in the first frame's representation, in its <name>-frames directory.
  4. Reopen the result and check family, frame count, geometry, pixel type, FPS, and first/last frame. A SER header has no frame-rate field: a SER AfterNight writes keeps each frame's exposure start in its timestamp trailer, and a reopened SER plays at the rate those timestamps give, rounded to a whole 1 to 60 frames per second - 1 frame per second when its frames state no exposure start. For .anseq, also confirm that the sibling frame directory was created and remains beside the list file.

Export a sequence

  1. Activate a sequence and choose Image > Sequence > Export....
  2. Choose Output Format. Use SER for a high-fidelity native sequence, AVI (RAW) for uncompressed 8-bit DIB frames, or MP4 with H.264/H.265/WEBM (VP9) for delivery. Codec is enabled only for MP4.
  3. Choose ... beside Output File Name. The selected format/codec normalizes the destination to .ser, .avi, .mp4, or .webm; the destination field is read-only and OK remains disabled until a path is chosen.
  4. Set FPS. This changes playback timing only; it does not interpolate, duplicate, or remove frames.
  5. For a CFA source, leave Debayer CFA off to preserve mosaic samples - a SER keeps the mosaic, AVI and video store its samples as grey - or turn it on to demosaic every exported frame to RGB by the sequence's demosaic method. The option is hidden for a non-CFA source.
  6. Leave Autostretch off for data preservation. Turn it on only for a display-ready export: it applies the source view's current autostretch parameters and optional saturation/brightness/contrast to every frame.
  7. Leave Resize off to request source geometry. When it is on, choose a resolution and review the resulting width/height plus the fill rule. A video frame's odd width or height is cropped by one column or row even when Resize is off.
  8. Choose OK and watch Exporting Sequence.... The configuration controls remain locked while the worker uses the submitted settings snapshot. The progress dialog's Cancel stops the export, and nothing is written: an export is published only when its last frame is in. Closing the window during an export stops it, and the window closes when the stop lands. On success, AfterNight reports Sequence exported successfully! and closes the dialog; a failure shows Export Sequence Error with the reason and keeps the dialog open.
  9. Reopen or inspect the file externally. Check container/codec, frame count, geometry, FPS, first/last frame, and whether expected stretch/letterbox/crop choices are visible. Export success does not perform that readback.

Complete control and action reference

Save actions and file dialog

UI label/action Type and unit Default Valid values/constraints Effect Enabled, hidden, or ignored rules Trade-off or side effect Scope Persistence
Save as... Menu/toolbar action; Ctrl+Shift+S Disabled without an active image One active still or sequence view Opens the standard save dialog and writes the active data. Same handler as Save File...; there is no write-back-without-prompt action. Successful save clears pending changes and makes the new file the view's source, when the view still shows what was written. Active view Last directory is shared and persisted.
Save File... Image > Actions action Disabled without active image content Same as Save as Runs exactly the same save workflow. Enabled with the Image Actions menu. Same output and pending-state effects as Save as. Active view Same shared last directory.
File name and destination Save-file dialog Active view name in the last-open directory Writable path; still extension must be FITS/XISF/TIFF/PNG/JPEG; sequence suffix should match current family Selects output and engine codec/family. Sequence filters depend on current family. The dialog's all-formats entry is not a promise that cross-family renaming converts data. Existing destinations are replaced only once the new file is complete. One output Selected directory becomes the next shared open/save directory.
File type filter Selector Still: General > Default Save Format (TIFF on a clean profile); sequence: family-specific Still: TIFF, FITS, PNG, XISF, JPEG. Sequence: SER, .anseq, or the source video's recognized container suffix. Supplies the default suffix and narrows file choices. Video save preserves .avi, .mp4, .mpg, .mpeg, .mov, .mkv, or .webm; an unrecognized source suffix falls back to .mp4. The actual filename extension controls still-codec dispatch. RAW is never offered for still save. A display format may convert precision or discard astronomy metadata. One output Still default persists as general/defaultSaveFormat; current filter selection itself is dialog-local.
Confirm/Save Dialog action — Valid selected path Starts background save and shows progress. A still write may finish before a stop is observed; a stopped still write leaves nothing. Sequence copy checks cancellation where implemented. A mosaic is refused for PNG and JPEG, and an X-Trans mosaic for FITS too, before anything is written. Adds successful destination to recent files and clears pending state when the view still shows what was written. Active view The new file becomes the view's source.
Cancel Dialog/progress action — Click/close Before start, writes nothing. During a sequence copy or export, stops it; nothing is published. A cancelled save is only logged; it does not add a recent file or clear the active view's pending-change marker. A still write may finish before the cancellation check. A failed or cancelled write leaves an existing destination as it was and nothing beside it. Current operation None.

Sequence Export dialog

UI label/action Type and unit Default Valid values/constraints Effect Enabled, hidden, or ignored rules Trade-off or side effect Scope Persistence
Output Format Selector SER on first use; last saved value later SER; AVI (RAW); MP4 Creates the destination writer and adjusts suffix/filter behavior. Changes Codec enablement and rewrites an already selected filename's suffix. SER keeps 8-bit frames at 8 bits and writes every other at 16; raw AVI converts to 8-bit; MP4/WebM are delivery encodings. Whole export Stored in process setting __EXPORT_SEQUENCE__ on dialog close.
Codec Selector h264 on first use; last saved value later h264; h265; WEBM Selects H.264 MP4, H.265 MP4, or VP9 WebM encoding. Enabled only when Output Format is MP4; ignored for SER/AVI. Video encoding is lossy and drops astronomy metadata/history. Whole export Stored on dialog close.
Output File Name / ... Read-only path and browse action Empty .ser, .avi, .mp4, or .webm selected by current output mode Chooses destination and enables OK. Manual typing is unavailable; OK stays disabled until browse returns a path. Existing file replacement is confirmed by the file dialog; no backup/readback follows. One output Directory stored under __EXPORT_SEQUENCE_CONTROL__; filename not persisted.
FPS Decimal frames/second Source sequence FPS (1.0 when it states none), clamped to control range 1.0-60.0; step 0.3 Sets the destination playback rate. Values outside the UI range clamp when loaded. Timing changes without frame interpolation. AVI and video store the exact fraction asked; a SER stores no frame rate of its own, only each frame's exposure start in its trailer. Whole export Not persisted.
Debayer CFA Checkbox Off Off/On Off preserves CFA mosaic frames; on requests demosaiced RGB frames. Visible and enabled only when the source sequence reports CFA data. Demosaicing changes channel layout and pixel values and cannot reconstruct the original mosaic from the export. Every exported frame Not persisted.
Autostretch Checkbox Off Off/On Stretches every frame as Apply Stretch does, through the presentation the view shows, with the source view's current shadows clipping, target background, linked-channel, neutralization, calibration, saturation and brightness/contrast settings. Export-only; the normal save path never applies viewer autostretch. Permanently changes exported pixels and adds per-frame CPU cost; it is not reversible from the output. Every exported frame Not persisted.
Resize Checkable group Off Off/On Enables output geometry controls; off requests source dimensions. A video still crops an odd width or height by one column or row with Resize off. Resampling changes pixels/WCS applicability and costs CPU/memory. Every exported frame Enablement not persisted.
Resolution Selector Preserve Ratio on first use; last saved value later Preserve Ratio; Free Ratio; Full HD; 4K; 8K Selects source-linked dimensions or nominal preset dimensions (1920 x 1080, 3840 x 2160, 7680 x 4320). Width/height controls range from 4 to twice the source dimension or to 7680 (width) / 4320 (height), whichever is larger, so a preset is never clamped. A video only crops an odd width or height by one. Upsampling cannot add source detail. Resize target Selector persists; dimensions do not.
Width / Height Integer pixels Source width/height 4 through twice the corresponding source dimension, or 7680 / 4320 when that is larger Defines target canvas. In Preserve Ratio, editing one recalculates the other from source aspect. Disabled for Full HD/4K/8K; enabled for Preserve/Free Ratio. A video frame's odd width or height is cropped by one column or row. Resize target Not persisted.
Fill mode Selector Fit Fit; Fill; Stretch; Center Chooses Lanczos4 scaling/canvas behavior for preset targets. Enabled only for Full HD/4K/8K. Preserve/Free Ratio keep the current Fit value internally. Fit letterboxes; Fill crops; Stretch distorts aspect; Center adds black canvas and can crop content larger than target. Every resized frame Not persisted.
Reset Button — Click action Restores Preserve Ratio, source width/height, and Resize off. Does not reset format, codec, FPS, autostretch, output path, or fill mode. A previously chosen path remains active. Current dialog Persisted selectors remain until dialog close writes current values.
OK Button Disabled until output path exists Valid chosen path Snapshots the selected path, format, codec, FPS, CFA/autostretch/resize settings, dimensions, and fill mode, then starts a worker with percentage progress. Configuration controls and the dialog button box are disabled until cancellation, failure, or completion. The dialog remains open after cancellation/failure and closes after success. Full-sequence decode/transform/write; a failed or cancelled export leaves nothing at the destination. Whole sequence Format/codec/resolution are saved when the dialog later closes.
Cancel / window close Dialog action Enabled before export Click/close Closes without starting a new export. While an export runs, closing the window stops it and the window closes when the stop lands; cancellation is also available from the progress dialog. Closing the configuration dialog before/after a run stores format, codec, and resolution. Does not remove an earlier completed output. Current dialog Stores the three selectors.

Behavior and state model

Save dispatch and precision

Saving and Sequence Export write through the engine's output transaction and sinks. The standard still path decides, when the save is confirmed, how the image is written: the representation each container below holds nearest the image's own, the compression the Export settings give, and the metadata it carries. When the image's representation is not one the container holds, a copy is converted at corresponding full scales in double precision to the nearest value, ties to even, as the processes and the command-line tool round; floating data in physical units is converted as a fraction of full scale, as the viewer shows it. Codec selection is extension-based and case-insensitive; the file-dialog filter does not override a conflicting extension.

Output Pixel/sample behavior Compression
FITS Writes supported signed/unsigned 8/16/32-bit integer and 32/64-bit floating samples through matching fixed-width CFITSIO types. Signed 8-bit and full-range unsigned 32-bit round trips are regression-tested. RGB is stored as three planes. A Bayer mosaic keeps its pattern; an X-Trans mosaic is refused. A 64-bit integer FITS file whose stored values exceed 2^53 is refused when it is opened. No user-facing FITS compression in this path. The stored export/fitsFloatFormat preference is not consumed.
XISF Preserves unsigned 8/16/32-bit and float 32/64-bit samples. A signed image is written as the unsigned representation of its own width. None (the default), or lossless zlib, LZ4, LZ4-HC or Zstandard, with the bytes of each sample shuffled unless that is turned off, and an optional SHA-256 checksum, as Settings > Export gives them. Zstandard is read only by readers of Revision 1 of the XISF specification.
TIFF Writes and reloads the active sample bit width and unsigned/signed/floating sample format, including signed 8-bit. The payload is divided into strips of about a quarter of a megabyte. None, lossless LZW, lossless ZIP/Deflate, or JPEG. JPEG applies only to 8-bit TIFF; higher-depth input is written with LZW, and the session console says so.
PNG Preserves unsigned 8/16-bit samples. Signed 8/16-bit data converts to matching unsigned depth; 32-bit integer and floating data converts to unsigned 16-bit. A colour filter array mosaic is refused. Lossless DEFLATE level 0-9; level affects size/time, not decoded pixels.
JPEG Converts all data to unsigned 8-bit grayscale or RGB before encoding. A colour filter array mosaic is refused. Lossy JPEG quality 1-100.

Saving does not flatten a display stretch. If the image itself was stretched by a process, those changed pixels are saved; if only viewer Autostretch is on, the original underlying samples are saved.

Metadata and processing history

  • FITS and XISF always carry the header cards the image was read with, its world coordinates among them, while the structural keywords are written afresh. A long processing-state string is stored across CONTINUE cards. Geometry-changing work drops the cards that no longer describe the image, so a turned or resized image carries no stale WCS.
  • With Embed EXIF enabled, a JPEG, TIFF, or PNG carries the image's EXIF record - each format's allowed subset - as part of the same write, so a save that succeeds wrote it. With it disabled, a raster file carries none. The record is not stamped with the time of the write, and a FITS GAIN card is not written as the Exif gain-control field.
  • Embed processing history in FITS header is kept as a setting and writes nothing: no file carries an image's processing history. Existing FITS HISTORY records the image was read with are carried as its other cards are.
  • Sequence Export does not embed AfterNight image history. SER carries its native sequence/image fields and each frame's exposure start in its timestamp trailer; an image list's frames carry their header cards; raw AVI/MP4/WebM are display containers and should not be treated as astronomy-metadata archives.

Sequence save versus export

Save reads every frame from the sequence's file and writes it, as the file holds it, through the writer of the container the chosen path names: SER (8-bit frames at 8 bits, every other at 16, each frame's exposure start in the timestamp trailer), an image list (each frame a FITS file with its header cards in the first frame's representation, beside a new .anseq), uncompressed AVI, or MP4, Matroska or WebM by the software encoder (8-bit frames, a mosaic as its grey samples). A .mov path is written as an MP4 container; .mpg and .mpeg are not written. Every container is written privately and published only when the last frame is in.

Export reads every frame from the sequence's file, demosaics it when asked, stretches it, resizes it and writes it privately, publishing the file only when the last frame is in. Autostretch runs before resize. Resize uses Lanczos4; Fit scales inside a black canvas, Fill scales then center-crops, Stretch changes aspect ratio, and Center places unscaled data on a black canvas. A video frame's odd width or height is cropped by one column or row, and H.264 and H.265 are encoded by the software encoders, VP9 into WebM. Colour frames are encoded through the BT.709 matrix, and AVI and video frames are stored upright. An AVI that would need more index sections than its writer reserves is refused rather than continued in a second file.

Inputs, outputs, and metadata

Operation Input Output/naming Metadata/history Overwrite and recovery
Save still Active underlying image One extension-selected file, proposed name is the view's unique name Format behavior above; no display overlays/stretch; successful save clears pending state File dialog confirms replacement. Written beside the destination and moved into place only when complete; reopen and verify.
Save SER Active SER New .ser; every frame rewritten as the file holds it, a mosaic kept Native SER fields; each frame's exposure start in the timestamp trailer, an unknown entry for a frame that states none; no frame-rate field; no image-history embedding Published whole or not at all; a failed or cancelled copy leaves nothing.
Save Image List Active .anseq New .anseq plus <name>-frames FITS directory First frame supplies sequence metadata; frames are rewritten as FITS with their header cards, in the first frame's representation Treat list and directory as one artifact. A failed copy leaves nothing.
Save FFmpeg video Active video sequence Frames decoded and written to the container the path names: uncompressed AVI, or MP4 (also for .mov), Matroska or WebM by the software encoder; .mpg/.mpeg are refused Frames re-encoded at 8 bits; no astronomy metadata Published whole or not at all.
Export SER Decoded whole sequence Selected .ser Supported native SER frame layout; each exported frame's exposure start in the timestamp trailer, an unknown entry for a frame that states none; no frame-rate field; no AfterNight image history Published whole or not at all; a failed or cancelled export leaves nothing.
Export AVI (RAW) Decoded whole sequence Selected .avi with raw DIB frames Converts frames to unsigned 8-bit; the exact FPS fraction Large uncompressed output; no astronomy metadata archive.
Export MP4/WebM Decoded whole sequence H.264/H.265 .mp4 or VP9 .webm Delivery video, the exact FPS fraction, every frame including the last; astronomy metadata/history not preserved Lossy; inspect actual output.

Performance and responsiveness

Still save runs on a worker while a progress dialog is shown, from the image as it was when the save was confirmed. FITS, TIFF, PNG, JPEG, and XISF encode the whole image; a conversion, compression and metadata work add CPU and disk time. You can keep working, edit, or close the view meanwhile: the file holds what was confirmed, and an edit made in the meantime keeps the view's changes pending.

Sequence copy/export scales with frame count, decoded pixels, channels, and destination encoding. Every sequence save decodes and rewrites each frame, one admitted step at a time. Image-list save writes one FITS file per frame. The video encoder runs on one thread. Autostretch measures each frame as the view does; resize adds Lanczos4 work and temporary images; raw AVI can be very large; H.264/H.265/ VP9 trade CPU for smaller delivery files. Use a short representative sequence and a new output path before committing a long export.

Worked example

  • Evidence mode: Source-and-test-derived.
  • Starting state, actions, settings, checkpoints, result, and limitations: for a floating-point RGB processing master, keep General > Default Save Format at TIFF or choose FITS/XISF explicitly, then save to a new name. Reopen it and verify geometry, three channels, floating sample type for FITS/TIFF/XISF, and required astronomy metadata. For a delivery copy, choose PNG only after accepting unsigned-16 conversion, or JPEG only after accepting unsigned-8 conversion and lossy quality 95. For a sequence delivery, choose Export, retain source FPS, leave Autostretch/Resize off for a control export, and verify frame count, dimensions, FPS, and boundary frames after writing. Focused tests cover codec round trips, FITS overwrite/header behavior, XISF header behavior, invalid extensions, the mosaic refusal, whole-or-nothing publication, and each export container's frame rate and geometry. This example does not claim a measured compression ratio, external-player compatibility, EXIF round trip, or visual equivalence for lossy output.

Warnings and limitations

  • No plain Save/write-back exists. Every standard save opens a destination dialog. Save as and Save File are aliases.
  • Successful save clears the pending marker only when the view still shows what was written, and then makes the new file the view's source.
  • A still save is whole or absent. A failed or stopped write leaves an existing destination as it was and no partial file beside it.
  • Saving a video re-encodes it. Every frame is decoded and written again at 8 bits through the software encoder; .mpg and .mpeg cannot be written. Keep the original.
  • A selected filter cannot force a codec. The final extension controls still dispatch; missing or unsupported extensions fail.
  • TIFF JPEG compression becomes LZW for non-8-bit samples, as the session console says. PNG and JPEG perform the precision conversions listed above. XISF writes a signed image as the unsigned representation of its width.
  • A colour filter array mosaic cannot be saved as PNG or JPEG, and an X-Trans mosaic cannot be saved as FITS either.
  • A SER file stores no frame rate of its own: reopened, it plays at the rate its frames' timestamps give, and at 1 frame per second when they state none - a SER exported from a video, for one, whose frames carry no exposure start.
  • An image list's frames are written in the first frame's representation; a frame of a deeper one is narrowed to it.
  • Embed processing history writes nothing; keep provenance separately.
  • Viewer autostretch, masks, overlays, selected display channel, zoom, and annotations are not included in still saves. Sequence Export Autostretch is different: it permanently transforms exported pixels.
  • Sequence Export resolution presets can be clamped by the UI range, and a video frame's odd width or height is cropped by one. Inspect the dimensions of the actual output.
  • A sequence export or copy that fails or is cancelled leaves nothing at its destination; a frame the encoder refuses fails the export with its error.

Troubleshooting

Symptom or exact error Verified cause/enablement path Recovery Evidence source
Save actions are disabled No active view contains image data. Activate an image/sequence view and retry. ActionStateCoordinator.cpp; FileManager::saveFile().
No selected image to save The action reached FileManager without a current active view. Select the intended view; wait for it to finish opening. FileManager::saveFile().
File save error: the product writes FITS, XISF, TIFF, PNG and JPEG files only The still filename has no recognized output extension or a mismatched unsupported suffix. Choose .fit/.fits/.fts, .xisf, .tif/.tiff, .png, .jpg/.jpeg/.jpe; use the matching filter. FilePolicies.cpp (buildExportIntent); FileSaveTest.cpp.
File save error: no sequence container the product writes is named by ... A sequence was saved to a suffix AfterNight does not write, such as .mpg or .mpeg. Save to .ser, .anseq, .avi, .mp4, .mkv or .webm. SequenceCompanions.cpp (writeSequenceFile); SequenceContainers.cpp.
a colour filter array mosaic cannot be written as PNG or JPEG, which cannot state its filter array; write it as FITS, XISF or TIFF, or demosaic it first The active image is an undemosaiced mosaic. Save as FITS, XISF, or TIFF, or demosaic the image first. FilePolicies.cpp; ImageViewFiles.cpp.
an X-Trans mosaic cannot be written as FITS, PNG or JPEG, none of which can state its six-by-six filter array; write it as XISF or TIFF, or demosaic it first The active image is an undemosaiced X-Trans mosaic. Save as XISF or TIFF, or demosaic the image first. FilePolicies.cpp; ImageViewFiles.cpp; FilePoliciesTest.AnXTransMosaicIsRefusedForFitsWhichStatesATwoByTwoPatternOnly.
TIFF is larger/different than expected Compression setting differs, or JPEG was requested for non-8-bit input and LZW was written instead. Inspect pixel depth and Export settings; use None/LZW/ZIP for lossless work. FilePolicies.cpp.
Processing history is absent from saved FITS No file carries processing history; the setting writes nothing. Preserve provenance separately and inspect existing FITS HISTORY. FilePolicies.h.
EXIF is absent although enabled The format-specific allowed set excluded it, or the image carried none. Verify with EXIF viewer; keep the source/master metadata and use FITS/XISF for astronomy fields. FilePolicies.cpp.
Exported MP4 dimensions differ A video stores even sizes, so an odd width or height was cropped by one. Choose even dimensions and verify output geometry. SequenceContainers.cpp; Export dialog source.
A reopened SER plays at 1 FPS A SER has no frame-rate field, and its frames' timestamps give no rate: its frames stated no exposure start, as a video's do not, or fewer than two distinct ones. Keep the rate with the file's notes, or export AVI/video, which store it. SequenceContainers.cpp (serTimestampRate); SequenceContainersTest.ASerWrittenKeepsEachFramesExposureStartAndItsRate.
Exported result is stretched/cropped/letterboxed Autostretch or Resize was enabled; fill mode defines scaling/canvas behavior. Reset Resize, turn Autostretch off, or deliberately choose Fit/Fill/Stretch/Center and retry to a new file. ExportSequenceControl.cpp.
  • Use Sequences to create, inspect, extract, or convert the active sequence before deciding between a same-family save and export.
  • Use Supported Formats for a concise input/output matrix and File Formats for the authoritative precision, compression, and metadata reference.
  • Configure still defaults under Settings, then verify the actual output rather than inferring it from a preference.
  • Inspect Image Summary and FITS Header, EXIF, And Astrometry Metadata after reopening an important output.
  • Continue to Extract Sequence when only an inclusive frame range should be written or processed.

References and provenance