Windows 和 Linux 上的 OpenCV 不同结果

Question

我正在为基于 Rust 的 OpenCV 编写一个跨平台包装器。我写了几个测试来检查我的包装器是否正常工作。一些测试通过了，一些测试失败了，值略有不同，但一个测试的结果完全不同。

右边的数字是我在 windows 上得到的，左边的是我在 linux

上得到的

---- compare_hist_chi_square stdout ----
    thread 'compare_hist_chi_square' panicked at '2697.981816285168 == 1360.7', tests/test_imgproc.rs:81:4
---- compare_hist_bhattacharyya stdout ----
    thread 'compare_hist_bhattacharyya' panicked at '0.6798259690477988 == 0.6679', tests/test_imgproc.rs:81:4
---- compare_hist_chi_square_alternative stdout ----
    thread 'compare_hist_chi_square_alternative' panicked at '41.65613074156445 == 41.027', tests/test_imgproc.rs:81:4
---- compare_hist_correlation stdout ----
    thread 'compare_hist_correlation' panicked at '0.20456957916644988 == 0.211', tests/test_imgproc.rs:81:4
---- compare_hist_intersection stdout ----
    thread 'compare_hist_intersection' panicked at '5.440850785933435 == 5.682', tests/test_imgproc.rs:81:4
---- compare_hist_kullback_leibler_divergence stdout ----
    thread 'compare_hist_kullback_leibler_divergence' panicked at '55.71912075710992 == 54.06287', tests/test_imgproc.rs:81:4

我试图从 this article 重现代码。我拍摄了相同的图像并希望获得相同的结果。然而，这并没有发生。

这里是一些测试的Rust代码（仅供参考）：

extern crate cv;
extern crate float_cmp;
mod utils;

use cv::*;
use cv::imgproc::*;
use float_cmp::ApproxEqRatio;
use utils::*;

#[test]
#[should_panic]
fn compare_hist_different_dimensions_panic() {
    let first_image = load_unchanged("assets/Histogram_Comparison_Source_0.jpg");
    let second_image = load_unchanged("assets/Histogram_Comparison_Source_1.jpg");
    let _ = first_image.compare_hist(&second_image, HistogramComparisionMethod::Corellation).unwrap();
}

#[test]
fn compare_hist_correlation() {
    compare_hist(HistogramComparisionMethod::Corellation, 0.211);
}

#[test]
fn compare_hist_chi_square() {
    compare_hist(HistogramComparisionMethod::ChiSquare, 1360.7);
}

#[test]
fn compare_hist_intersection() {
    compare_hist(HistogramComparisionMethod::Intersection, 5.682);
}

#[test]
fn compare_hist_bhattacharyya() {
    compare_hist(HistogramComparisionMethod::Bhattacharyya, 0.6679);
}

#[test]
fn compare_hist_chi_square_alternative() {
    compare_hist(HistogramComparisionMethod::ChiSquareAlternative, 41.027);
}

#[test]
fn compare_hist_kullback_leibler_divergence() {
    compare_hist(
        HistogramComparisionMethod::KullbackLeiblerDivergence,
        54.06287,
    );
}

fn compare_hist(method: HistogramComparisionMethod, expected_result: f64) {
    let first_image = get_image_histogram("assets/Histogram_Comparison_Source_0.jpg");
    let second_image = get_image_histogram("assets/Histogram_Comparison_Source_1.jpg");
    let result = first_image.compare_hist(&second_image, method).unwrap();
    assert_eq(result, expected_result);
}

fn get_image_histogram(path: &'static str) -> Mat {
    let image = load_unchanged(path);
    let image = image.cvt_color(ColorConversionCodes::BGR2HSV);
    let hsize = [50, 60];
    let h_ranges = [0_f32, 180_f32];
    let s_ranges = [0_f32, 256_f32];
    let ranges = [
        h_ranges.as_ptr() as *const f32,
        s_ranges.as_ptr() as *const f32,
    ];
    let channels = [0, 1];
    let image = image.calc_hist(
        channels.as_ptr(),
        Mat::new(),
        2,
        hsize.as_ptr(),
        ranges.as_ptr(),
    );
    let image = image.normalize(0_f64, 1_f64, NormTypes::NormMinMax);
    image
}

fn assert_eq(a: f64, b: f64) {
    assert!(a.approx_eq_ratio(&b, 0.001), format!("{} == {}", a, b));
}

pub fn load_unchanged<P: AsRef<Path>>(img: P) -> Mat {
    let buf = load_image_as_buf(img);
    Mat::imdecode(&buf, ImreadModes::ImreadUnchanged)
}

fn load_image_as_buf<P: AsRef<Path>>(img: P) -> Vec<u8> {
    let mut d = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
    d.push(img);
    let mut buf = Vec::new();
    File::open(d).unwrap().read_to_end(&mut buf).unwrap();
    buf
}

可能是因为 jpg 和不同平台的 jpg 读者不同，但它不能解释 2697.98 vs 1360.7，几乎是 2 倍的差异！

这里可能出了什么问题？ Here is my entire pull request 我正在尝试添加此功能的地方（小心，其中包含一些 Rust 代码）

Answer 1

感谢@VTT，这个问题的发生是因为不同平台上的jpg解释不同。切换到png解决问题

Windows 和 Linux 上的 OpenCV 不同结果

OpenCV different results on Windows and Linux

c++

linux

windows

opencv

cross-platform