## 2.4.0
- Added `esp_ipa_pipeline_set_config(handle, config, sensor, metadata)` to rebuild IPA modules from a new `esp_ipa_config_t` (not thread-safe): create a temporary pipeline (IPA + map), run `init` into `metadata`, swap `ipa_array`/`map`/`config` into the caller's handle, then destroy the temporary pipeline (which now owns the old modules); on failure destroy the temporary pipeline and leave the handle unchanged
- Supported multiple JSON configuration files for the same sensor; those files must each set a unique `description` (other sensors may reuse the same value)
- Added AWB model 3 (fixed CT): JSON `fixed_ct { default_ct, presets:[{ct,rg,bg},...] }`; runtime `esp_ipa_awb_set_fixed_ct(handle, K)` (exact preset match, else `ESP_ERR_INVALID_ARG`); process applied active CT preset; published pipeline `ct` for ACC
- Added IAN: JSON `ian.color_temp.disable`; when `true`, kept the `color_temp` block but did not generate IAN CT (`config->ct` stays NULL, so `cal_ct` does not overwrite `ct`)
- Updated AGC: `luma_low`/`luma_high` hold band followed the PWL/meter-shifted target so gain did not hunt inside the band
- Added JSON global `writable`: when `true`, stripped `const` from that file's generated IPA config data so parameters are runtime-writable
- Updated ACC LSC: gain nodes may omit nested `table` and set `scale` (optional `base_gain`) so config generation blended the base LSC arrays toward 1.0 (`out = 1 + (base - 1) * scale`) into static tables for that gain
## 2.3.0
- AEN: add backlight enhancement mode — detect backlight from histogram low/high ratios and env luma thresholds, debounce with `detect_count_threshold` / optional `detect_count_margin` (defaults to `detect_count_threshold`), smooth degree with `hist_ratio_filter`, then select a dedicated GAMMA table by backlight degree
- AGC: optional `gain_only` mode with fixed `exposure.fixed_exposure_time`; process path only adjusts gain
- AGC: skip `luma_low`/`luma_high` dead-band when `luma_pwl` is enabled so the PWL-shifted target can take effect
- ACC LSC: optional JSON `lsc.disable_gain` disables LSC when sensor gain is at or above the threshold (`<=0` keeps LSC always on by gain)
- AWB model_2: clear stale ref-point counters on stable frames so brief glare cannot skew CT
- Added support for setting and retrieving IPA pipeline parameters and status
- Added support for setting and retrieving the AGC maximum and minimum exposure values
## 2.2.0~1
- Fix `Failed to resolve component 'esp_ipa'` at configure time for component-registry consumers (namespaced `espressif__esp_ipa`): route the prebuilt's component-lib dependency through the `${COMPONENT_LIB}` target instead of the component name.
## 2.2.0
- Added information about the document system to README.md.
- Fixed linking issue on the Arduino platform.
- Added `libesp_ipa_newlib.a` to support builds using the Newlib C library.
- Added a static linking method that prevents unused functions from being included in the final firmware, reducing its size.
- ACC CCM: optional `gain_lut` blends the CT-selected CCM toward identity by sensor gain: `output = (1-s)*I + s*ccm`, where `s` is linearly interpolated from the LUT (`enable` + `table` with `gain` / `strength`)
- AGC: fix exposure and gain not being updated when average luma is zero
- IAN: fix `env.luma.avg` stuck at zero in very dark scenes
## 2.1.0
- AGC: optional JSON `agc.gain.max` maps to `esp_ipa_agc_config_t::max_gain`; when greater than zero, clamps the gain chosen by AGC after applying the sensor `min_gain` / `max_gain` limits; zero keeps previous behaviour (no extra cap)
- AWB **model_2 (zone classifier)**: classify each AWB by chromaticity against a **zone** table; neutral CT bands vote for illuminant selection, while **GREEN** / **SKIN** zones exclude those cells from the vote.
- Fix a compilation issue that occurred when no input configuration file was provided
- Fix issues in Model 1: did not check for the minimum required number of white points, and incorrectly cached previous RG and BG values.
## 2.0.0
- AGC adds environment-luma-driven target luma shift via a PWL (piecewise linear) curve
- New `luma_pwl` object in AGC JSON config with `enable` flag and `table` array
- When `enable` is `true`, the AGC reads `env.luma.avg` each frame and linearly interpolates `luma_shift` from the table, shifting `luma_target` accordingly
- `enable: false` disables the feature with zero overhead; other AGC logic is unaffected
- AWB sub-window: add green-based filter and linear tent weight (dark / mid / bright)
- AWB `update_rg_bg`: refactor to one metadata update path when red or blue step threshold is met.
- AGC supports the sensor without gain control
- Refactor esp_ipa_config Python code
- Separate algorithm modules into individual files to improve code maintainability
- Use f-strings to improve code readability
- Add environmental luminance mode to the AGC light metering algorithm
- **BREAKING CHANGE:** The type of "luma_threshold" in the "esp_ipa_agc_meter_light_threshold" structure has been changed from "uint32_t" to "uint8_t". Valid range is now 0-255. If your code uses values greater than 255, you must update them accordingly.
- Gamma controller now supports configuring each channel individually (R, G, and B)
- Fix issue where color temperature could not recover from excessively low values in certain cases
- Fix issue where RG and BG were calculated directly from statistics instead of using the current configuration's CT module
- Fix IAN hist low_value_radio and high_value_radio: sum all segment counts in [low_index_start..low_index_end] and [high_index_start..high_index_end] instead of using only the last segment (fixes back_light and AGC highlight logic)
## 1.3.1
- Fix ATC Json parameter compatibility
- Fix ISP header file compilation issue when esp-idf version >= 6.0
## 1.3.0
- Add auto BLC(black level correction) algorithm
## 1.2.0
- Add ATC model 0 algorithm
- Package the libesp_ipa.a library that compiled based on esp-idf master(v6.0.0)
## 1.1.0
- Modify the exposure adjustment algorithm of the part-anti-flicker mode
- If the target gain exceeds the maximum or minimum value, the AGC ignores the anti-flicker and uses all exposure time
## 1.0.1
- Fix the light flicker issue in the part-anti-flicker mode
## 1.0.0
- Add extended configuration to set hue, brightness and statistics window
- Add an autofocus control algorithm to set the sensor focus position by controlling the sensor motor
## 0.3.0~1
- Fix the compiling error with esp-idf v5.4-
## 0.3.0
- Add ATC to configure sensor AE target level by JSON configuration
- AGC different directions of gain and exposure adjustment support different speed parameters
- AGC supports the all exposure range in the part anti-flicker mode
- ACC supports LSC JSON configuration
- ACC adds CCM model 1 to calculate CCM by interpolation algorithm
- ADN JSON configuration supports to generate Gaussian matrix by sigma parameter
- AWB supports to configure statistics parameters
- Pipeline global variables support buffer pointer
- Pipeline supports to add customized IPA node
## 0.2.0
- Added auto color correction algorithm for ISP image color management module
- Added auto denoising algorithm for ISP image denoising module
- Added auto enhancement algorithm for ISP image enhancement module
- Added auto exposure and gain control algorithm for sensor exposure and gain control module
- Added image analysis algorithm to analyze image color temperature and luma
- Added pipeline global variable management functions
- Added script to transform JSON configuration file to C source code for algorithms
- Modified ESP-IDF version from v5.3 to v5.4 to support full ISP modules
## 0.1.0
- Initial version for esp_ipa component
### Enhancements
- Gray world algorithm for auto white balance
- Luma threshold algorithm for auto gain control