[人工智能]OpenCV Resize图像大小后的补边

python

def _resize_image(im, width, height):
    w, h = im.shape[1], im.shape[0]
    r = min(width / w, height / h)
    # print(w, h, r)
    new_w, new_h = int(w * r), int(h * r)
    # print(new_w, new_h)
    im = cv2.resize(im, (new_w, new_h))
    pw = (width - new_w) // 2
    ph = (height - new_h) // 2
    top, bottom = ph, ph
    left, right = pw, pw

    if top + bottom + new_h < height:
        bottom += 1

    if left + right + new_w < width:
        right += 1

    im = cv2.copyMakeBorder(im, top, bottom, left, right, borderType=cv2.BORDER_CONSTANT, value=114)

C++

float r = std::min(INPUT_W / (img.cols * 1.0), INPUT_H / (img.rows * 1.0));
int unpad_w = r * img.cols;
int unpad_h = r * img.rows;
cv::Mat re(unpad_h, unpad_w, CV_8UC3);
cv::resize(img, re, re.size());
cv::Mat out(INPUT_W, INPUT_H, CV_8UC3, cv::Scalar(114, 114, 114));
re.copyTo(out(cv::Rect(0, 0, re.cols, re.rows)));