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# SPDX-License-Identifier: BSD-2-Clause # # Copyright (C) 2019, Raspberry Pi Ltd # # ctt_lux.py - camera tuning tool for lux level from ctt_tools import * """ Find lux values from metadata and calculate Y """ def lux(Cam, Img): shutter_speed = Img.exposure gain = Img.againQ8_norm aperture = 1 Cam.log += '\nShutter speed = {}'.format(shutter_speed) Cam.log += '\nGain = {}'.format(gain) Cam.log += '\nAperture = {}'.format(aperture) patches = [Img.patches[i] for i in Img.order] channels = [Img.channels[i] for i in Img.order] return lux_calc(Cam, Img, patches, channels), shutter_speed, gain """ perform lux calibration on bayer channels """ def lux_calc(Cam, Img, patches, channels): """ find means color channels on grey patches """ ap_r = np.mean(patches[0][3::4]) ap_g = (np.mean(patches[1][3::4])+np.mean(patches[2][3::4]))/2 ap_b = np.mean(patches[3][3::4]) Cam.log += '\nAverage channel values on grey patches:' Cam.log += '\nRed = {:.0f} Green = {:.0f} Blue = {:.0f}'.format(ap_r, ap_b, ap_g) # print(ap_r, ap_g, ap_b) """ calculate channel gains """ gr = ap_g/ap_r gb = ap_g/ap_b Cam.log += '\nChannel gains: Red = {:.3f} Blue = {:.3f}'.format(gr, gb) """ find means color channels on image and scale by gain note greens are averaged together (treated as one channel) """ a_r = np.mean(channels[0])*gr a_g = (np.mean(channels[1])+np.mean(channels[2]))/2 a_b = np.mean(channels[3])*gb Cam.log += '\nAverage channel values over entire image scaled by channel gains:' Cam.log += '\nRed = {:.0f} Green = {:.0f} Blue = {:.0f}'.format(a_r, a_b, a_g) # print(a_r, a_g, a_b) """ Calculate y with top row of yuv matrix """ y = 0.299*a_r + 0.587*a_g + 0.114*a_b Cam.log += '\nY value calculated: {}'.format(int(y)) # print(y) return int(y) era/vivid.git/log/src/ipa/ipa-sign.sh'>