Function convRange

src/api/c/imgproc_common.hpp:47–79

template<typename To, typename Ti>
detail::Array<To> convRange(const detail::Array<Ti>& in,
                            const To newLow = To(0), const To newHigh = To(1)) {
    auto dims  = in.dims();
    auto input = common::cast<To, Ti>(in);
    To high =
        detail::getScalar<To>(detail::reduce_all<af_max_t, To, To>(input));
    To low = detail::getScalar<To>(detail::reduce_all<af_min_t, To, To>(input));
    To range = high - low;

    if (std::abs(range) < 1.0e-6) {
        if (low == To(0) && newLow == To(0)) {
            return input;
        } else {
            // Input is constant, use high as constant in converted range
            return detail::createValueArray(dims, newHigh);
        }
    }

    auto minArray = detail::createValueArray(dims, low);
    auto invDen   = detail::createValueArray(dims, To(1.0 / range));
    auto numer    = detail::arithOp<To, af_sub_t>(input, minArray, dims);
    auto result   = detail::arithOp<To, af_mul_t>(numer, invDen, dims);

    if (newLow != To(0) || newHigh != To(1)) {
        To newRange    = newHigh - newLow;
        auto newRngArr = detail::createValueArray(dims, newRange);
        auto newMinArr = detail::createValueArray(dims, newLow);
        auto scaledArr = detail::arithOp<To, af_mul_t>(result, newRngArr, dims);

        result = detail::arithOp<To, af_add_t>(newMinArr, scaledArr, dims);
    }
    return result;
}

}  // namespace common
}  // namespace arrayfire