app.py

import cv2
import numpy as np
import json
import gradio as gr
import os
from lxml import etree

# ---------------- Helper functions ----------------
def get_rotated_rect_corners(x, y, w, h, rotation_deg):
    rot_rad = np.deg2rad(rotation_deg)
    cos_r, sin_r = np.cos(rot_rad), np.sin(rot_rad)
    R = np.array([[cos_r, -sin_r], [sin_r, cos_r]])
    cx, cy = x + w/2, y + h/2
    local_corners = np.array([[-w/2,-h/2],[w/2,-h/2],[w/2,h/2],[-w/2,h/2]])
    rotated_corners = np.dot(local_corners, R.T)
    return (rotated_corners + np.array([cx,cy])).astype(np.float32)

def preprocess_gray_clahe(img):
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    clahe = cv2.createCLAHE(clipLimit=3.0, tileGridSize=(8,8))
    return clahe.apply(gray)

def detect_and_match(img1_gray, img2_gray, method="SIFT", ratio_thresh=0.78):
    if method=="SIFT": detector=cv2.SIFT_create(nfeatures=5000); matcher=cv2.BFMatcher(cv2.NORM_L2)
    elif method=="ORB": detector=cv2.ORB_create(5000); matcher=cv2.BFMatcher(cv2.NORM_HAMMING)
    elif method=="BRISK": detector=cv2.BRISK_create(); matcher=cv2.BFMatcher(cv2.NORM_HAMMING)
    elif method=="KAZE": detector=cv2.KAZE_create(); matcher=cv2.BFMatcher(cv2.NORM_L2)
    elif method=="AKAZE": detector=cv2.AKAZE_create(); matcher=cv2.BFMatcher(cv2.NORM_HAMMING)
    else: return None,None,[]
    
    kp1, des1 = detector.detectAndCompute(img1_gray,None)
    kp2, des2 = detector.detectAndCompute(img2_gray,None)
    if des1 is None or des2 is None: return None,None,[]
    
    raw_matches = matcher.knnMatch(des1,des2,k=2)
    good = [m for m,n in raw_matches if m.distance < ratio_thresh*n.distance]
    return kp1, kp2, good

# ---------------- XML overlay helper using lxml ----------------
def extract_points_lxml(xml_path):
    tree = etree.parse(xml_path)
    root = tree.getroot()
    transform = root.find('.//transform')
    points = {}
    for pt in transform.findall('.//point'):
        pt_type = pt.attrib['type']
        x = float(pt.attrib['x'])
        y = float(pt.attrib['y'])
        points[pt_type] = (x,y)
    return points

def draw_polygon_on_image(img, points_dict):
    ordered_points = ['TopLeft','TopRight','BottomRight','BottomLeft']
    polygon = [points_dict[pt] for pt in ordered_points]
    pts = np.array(polygon, np.int32).reshape((-1,1,2))
    img_copy = img.copy()
    cv2.polylines(img_copy, [pts], isClosed=True, color=(0,0,255), thickness=3)
    for px, py in polygon:
        cv2.circle(img_copy, (int(px),int(py)), 5, (255,0,0), -1)
    return img_copy

# ---------------- Padding Helper ----------------
def pad_to_size(img, target_h, target_w):
    h, w = img.shape[:2]
    canvas = np.ones((target_h, target_w,3), dtype=np.uint8)*255
    canvas[:h,:w] = img
    return canvas

def match_img_to_reference(match_img, ref_h, ref_w):
    h, w = match_img.shape[:2]
    scale = ref_w / w
    new_w = ref_w
    new_h = int(h * scale)
    resized = cv2.resize(match_img, (new_w,new_h))
    if new_h < ref_h:
        canvas = np.ones((ref_h, ref_w,3), dtype=np.uint8)*255
        canvas[:new_h,:new_w] = resized
        return canvas
    else:
        return resized

# ---------------- Main Function ----------------
def homography_all_detectors(flat_file, persp_file, json_file, xml_file):
    flat_img = cv2.imread(flat_file)
    persp_img = cv2.imread(persp_file)
    mockup = json.load(open(json_file.name))
    roi_data = mockup["printAreas"][0]["position"]
    roi_x, roi_y = roi_data["x"], roi_data["y"]
    roi_w, roi_h = mockup["printAreas"][0]["width"], mockup["printAreas"][0]["height"]
    roi_rot_deg = mockup["printAreas"][0]["rotation"]

    flat_gray = preprocess_gray_clahe(flat_img)
    persp_gray = preprocess_gray_clahe(persp_img)
    xml_points_dict = extract_points_lxml(xml_file.name)

    methods = ["SIFT","ORB","BRISK","KAZE","AKAZE"]
    gallery_paths = []
    download_files = []

    for method in methods:
        kp1,kp2,good_matches = detect_and_match(flat_gray,persp_gray,method)
        if kp1 is None or kp2 is None or len(good_matches)<4: continue

        match_img = cv2.drawMatches(flat_img,kp1,persp_img,kp2,good_matches,None,flags=2)

        # ROI on perspective image
        roi_corners_flat = get_rotated_rect_corners(roi_x,roi_y,roi_w,roi_h,roi_rot_deg)
        src_pts = np.float32([kp1[m.queryIdx].pt for m in good_matches]).reshape(-1,1,2)
        dst_pts = np.float32([kp2[m.trainIdx].pt for m in good_matches]).reshape(-1,1,2)
        H,_ = cv2.findHomography(src_pts,dst_pts,cv2.RANSAC,5.0)
        persp_roi = persp_img.copy()
        if H is not None:
            roi_corners_persp = cv2.perspectiveTransform(roi_corners_flat.reshape(-1,1,2),H).reshape(-1,2)
            cv2.polylines(persp_roi,[roi_corners_persp.astype(int)],True,(0,255,0),2)
            for px,py in roi_corners_persp: cv2.circle(persp_roi,(int(px),int(py)),5,(255,0,0),-1)

        # XML GT overlay on perspective
        xml_gt_img = draw_polygon_on_image(persp_img, xml_points_dict)

        # Convert to RGB
        flat_rgb = cv2.cvtColor(flat_img,cv2.COLOR_BGR2RGB)
        match_rgb = match_img_to_reference(cv2.cvtColor(match_img,cv2.COLOR_BGR2RGB),
                                           flat_rgb.shape[0], flat_rgb.shape[1])
        roi_rgb = cv2.cvtColor(persp_roi,cv2.COLOR_BGR2RGB)
        xml_rgb = cv2.cvtColor(xml_gt_img,cv2.COLOR_BGR2RGB)

        # Determine max height and width
        max_h = max(flat_rgb.shape[0], match_rgb.shape[0], roi_rgb.shape[0], xml_rgb.shape[0])
        max_w = max(flat_rgb.shape[1], match_rgb.shape[1], roi_rgb.shape[1], xml_rgb.shape[1])

        # Pad images
        flat_pad = pad_to_size(flat_rgb, max_h, max_w)
        match_pad = pad_to_size(match_rgb, max_h, max_w)
        roi_pad = pad_to_size(roi_rgb, max_h, max_w)
        xml_pad = pad_to_size(xml_rgb, max_h, max_w)

        # 2x2 grid
        top = np.hstack([flat_pad, match_pad])
        bottom = np.hstack([roi_pad, xml_pad])
        combined_grid = np.vstack([top, bottom])

        base_name = os.path.splitext(os.path.basename(persp_file))[0]
        file_name = f"{base_name}_{method.lower()}.png"
        cv2.imwrite(file_name, cv2.cvtColor(combined_grid,cv2.COLOR_RGB2BGR))
        gallery_paths.append(file_name)
        download_files.append(file_name)

    while len(download_files)<5: download_files.append(None)
    return gallery_paths, download_files[0], download_files[1], download_files[2], download_files[3], download_files[4]

# ---------------- Gradio UI ----------------
iface = gr.Interface(
    fn=homography_all_detectors,
    inputs=[
        gr.Image(label="Upload Flat Image",type="filepath"),
        gr.Image(label="Upload Perspective Image",type="filepath"),
        gr.File(label="Upload mockup.json",file_types=[".json"]),
        gr.File(label="Upload XML file",file_types=[".xml"])
    ],
    outputs=[
        gr.Gallery(label="Results per Detector",show_label=True),
        gr.File(label="Download SIFT Result"),
        gr.File(label="Download ORB Result"),
        gr.File(label="Download BRISK Result"),
        gr.File(label="Download KAZE Result"),
        gr.File(label="Download AKAZE Result")
    ],
    title="Homography ROI Projection with Feature Matching & XML GT",
    description="Flat + Perspective images with mockup.json & XML. Grid aligned. Perspective GT overlay now uses XML lxml parsing."
)

iface.launch()