# SPDX-License-Identifier: BSD-2-Clause # # Copyright (C) 2019, Raspberry Pi Ltd # # 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) '>jmondi/pinephone Jacopo Mondi's clone of libcameragit repository hosting on libcamera.org
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path: root/utils/raspberrypi/ctt/colors.py
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# colors.py - Program to convert from RGB to LAB color space
def RGB_to_LAB(RGB):  # where RGB is a 1x3 array.   e.g RGB = [100, 255, 230]
    num = 0
    XYZ = [0, 0, 0]
    # converted all the three R, G, B to X, Y, Z
    X = RGB[0] * 0.4124 + RGB[1] * 0.3576 + RGB[2] * 0.1805
    Y = RGB[0] * 0.2126 + RGB[1] * 0.7152 + RGB[2] * 0.0722
    Z = RGB[0] * 0.0193 + RGB[1] * 0.1192 + RGB[2] * 0.9505

    XYZ[0] = X / 255 * 100
    XYZ[1] = Y / 255 * 100  # XYZ Must be in range 0 -> 100, so scale down from 255
    XYZ[2] = Z / 255 * 100
    XYZ[0] = XYZ[0] / 95.047  # ref_X =  95.047   Observer= 2°, Illuminant= D65
    XYZ[1] = XYZ[1] / 100.0  # ref_Y = 100.000
    XYZ[2] = XYZ[2] / 108.883  # ref_Z = 108.883
    num = 0
    for value in XYZ:
        if value > 0.008856:
            value = value ** (0.3333333333333333)
        else: