v2.6.0

v2.6.0 updates the core to MicroPython 1.9.2, switches find_line_segments() to the LSD algorithm, adds MT9V034 global-shutter sensor support, image.rotation_corr() perspective correction, sensor.sleep(), raw image saving, and OpenMV 4 board groundwork. find_line_segments(), several framesizes, and MicroPython behavior changed — read the breaking changes below.

Highlights

  • MicroPython 1.9.2 core update.

  • LSD line segments — find_line_segments() now uses the Line Segment Detector algorithm.

  • MT9V034 global-shutter sensor support.

  • image.rotation_corr() — X/Y/Z perspective rotation correction.

  • sensor.sleep() soft sleep mode and raw (uncompressed) image saving.

  • Breaking: find_line_segments() parameters, several framesize constants, and MicroPython behavior changed — see the breaking changes.

New features

  • image.rotation_corr() — added X/Y/Z perspective rotation correction with a rotation_correction.py example.

  • sensor.sleep(enable) — put the camera into a soft sleep mode (with a sleep-mode example).

  • Raw images — image.save() can now write raw (uncompressed) images.

  • MT9V034 — added global-shutter sensor support, exposing the sensor.MT9V034 constant.

  • Added a lens_correction.py example for image.lens_corr() and OpenMV 4 board support files (board config / bootloader / linker groundwork).

Other changes and improvements

  • Updated the bundled MicroPython to 1.9.2 (1.9 port plumbing, oofatfs); rewrote find_line_segments.py for the new LSD API (lens correction off by default); updated the host-side openmv API (init(portname) / exec_script / stop_script); lowered the OpenMV Cam M4 sensor clock (lower max FPS on the M4); the IDE Stop button now uses a hard forced exception to interrupt scripts more reliably.

Bug fixes

  • Fixed image.lens_corr() leaving stale pixels (the destination buffer is now cleared before remapping), blob.density() using integer division (always returned 0, #268), the OpenMV 2 (M4) UART pin mapping, and updated qrcodes_with_lens_corr.py to use QVGA.

Hardware and board support

  • MT9V034 global-shutter sensor.

  • OpenMV 4 — board support files (groundwork).

  • OpenMV 2 (M4) — UART pin-mapping fix.

Breaking API changes

User-visible API breaks between v2.5.0 and v2.6.0. Scope: Python C-modules in modules/ and Python libraries in scripts/libraries/.

Each change is tagged with its impact:

  • major — affects most scripts that used the feature; you will need to port code.

  • minor — narrow API; only affects scripts that used it.

  • behavior — same API, different results; re-check tuned scripts.

Changes are grouped by impact in that order. If you just want to port your code, jump to the migration checklist at the end. Each commit hash links to its diff on GitHub.

find_line_segments() switched to LSD (major)

image.find_line_segments() was rewritten to use the Line Segment Detector (LSD) algorithm. The old threshold / theta_margin / rho_margin / segment_threshold / x_stride / y_stride parameters were replaced with merge_distance and max_theta_diff (e.g. find_line_segments(merge_distance=0, max_theta_diff=15)). It is also no longer available on M4-class (OpenMV 2) boards.

Commits: 5a3153c8b, cbe2a4aeb

Invalid framesize constants removed (minor)

The invalid sensor.QQQQCIF / QQQCIF / QQQQSIF / QQQSIF / HQQQQVGA / HVGA framesize constants were removed (#261). Scripts using these must switch to a supported resolution.

Commits: 35ab0a26f

find_qrcodes() removed on the OpenMV Cam M4 (minor)

image.find_qrcodes() is no longer compiled in on M4-class (OpenMV 2) boards. Use an OpenMV 3 (M7) board or another code feature for QR detection on M4 hardware. Other boards are unaffected.

Commits: 7dff089e6

MicroPython updated to 1.9.2 (behavior)

The bundled MicroPython core was updated to 1.9.2. Standard-library and language behavior follows upstream MicroPython 1.9.2 — re-check scripts that depend on version-specific behavior. Notably, an image slice with a step other than 1 now raises OSError instead of NotImplementedError.

Commits: 11bed4b99

Migration checklist

For a clean port to v2.6.0 the typical work is:

  1. Rewrite find_line_segments() calls for the LSD parameters (merge_distance / max_theta_diff) and move that processing off the M4 (the LSD rework).

  2. Replace removed framesize constants with a supported resolution (the framesize removal).

  3. Move M4 QR-code detection to an M7 board (the find_qrcodes change).

  4. Re-validate version-specific behavior against MicroPython 1.9.2 (the MicroPython bump).

All other scripts run unchanged.