croper.py

"""
Croper Utility
--------------
Kelas utilitas untuk melakukan crop area tertentu (berbasis mask) pada gambar, lalu menyiapkan square crop image dan square mask.
Juga menyediakan fungsi untuk mengembalikan (restore) hasil modifikasi ke gambar asli.

Created by _drat | 2025
"""

import PIL
import numpy as np
from PIL import Image

class Croper:
    def __init__(
        self,
        input_image: PIL.Image,      # Gambar input (format PIL Image)
        target_mask: np.ndarray,     # Mask biner area target (array numpy)
        mask_size: int = 256,        # Ukuran akhir mask & image yang dihasilkan (default 256x256)
        mask_expansion: int = 20,    # Ekspansi area mask (agar crop lebih lebar)
    ):
        self.input_image = input_image
        self.target_mask = target_mask
        self.mask_size = mask_size
        self.mask_expansion = mask_expansion
    
    # Fungsi utama untuk crop area sesuai mask dan membentuk square crop & mask
    def corp_mask_image(self):
        target_mask = self.target_mask
        input_image = self.input_image
        mask_expansion = self.mask_expansion
        original_width, original_height = input_image.size

        # Cari koordinat bounding box area mask (area bertanda True/1)
        mask_indices = np.where(target_mask)
        start_y = np.min(mask_indices[0])
        end_y = np.max(mask_indices[0])
        start_x = np.min(mask_indices[1])
        end_x = np.max(mask_indices[1])

        mask_height = end_y - start_y
        mask_width = end_x - start_x

        # Ambil sisi terpanjang untuk square crop
        max_side_length = max(mask_height, mask_width)

        # Ekspansi area mask agar crop tidak terlalu sempit
        height_diff = (max_side_length - mask_height) // 2
        width_diff = (max_side_length - mask_width) // 2
        start_y = start_y - mask_expansion - height_diff
        if start_y < 0:
            start_y = 0
        end_y = end_y + mask_expansion + height_diff
        if end_y > original_height:
            end_y = original_height
        start_x = start_x - mask_expansion - width_diff
        if start_x < 0:
            start_x = 0
        end_x = end_x + mask_expansion + width_diff
        if end_x > original_width:
            end_x = original_width

        expanded_height = end_y - start_y
        expanded_width = end_x - start_x
        expanded_max_side_length = max(expanded_height, expanded_width)

        # Crop mask dari area yang sudah diekspansi
        crop_mask = target_mask[start_y:end_y, start_x:end_x]

        # Hitung posisi crop mask pada square mask
        crop_mask_start_y = (expanded_max_side_length - expanded_height) // 2
        crop_mask_end_y = crop_mask_start_y + expanded_height
        crop_mask_start_x = (expanded_max_side_length - expanded_width) // 2
        crop_mask_end_x = crop_mask_start_x + expanded_width

        # Buat square mask dengan area crop mask di tengah
        square_mask = np.zeros((expanded_max_side_length, expanded_max_side_length), dtype=target_mask.dtype)
        square_mask[crop_mask_start_y:crop_mask_end_y, crop_mask_start_x:crop_mask_end_x] = crop_mask
        square_mask_image = Image.fromarray((square_mask * 255).astype(np.uint8))

        # Crop image asli sesuai area ekspansi
        crop_image = input_image.crop((start_x, start_y, end_x, end_y))
        # Buat square image, lalu paste crop image di tengah
        square_image = Image.new("RGB", (expanded_max_side_length, expanded_max_side_length))
        square_image.paste(crop_image, (crop_mask_start_x, crop_mask_start_y))

        # Simpan koordinat/ukuran untuk keperluan restore nanti
        self.origin_start_x = start_x
        self.origin_start_y = start_y
        self.origin_end_x = end_x
        self.origin_end_y = end_y

        self.square_start_x = crop_mask_start_x
        self.square_start_y = crop_mask_start_y
        self.square_end_x = crop_mask_end_x
        self.square_end_y = crop_mask_end_y

        self.square_length = expanded_max_side_length
        self.square_mask_image = square_mask_image
        self.square_image = square_image
        self.corp_mask = crop_mask

        # Resize hasil square mask & image ke mask_size (misal: 256x256) untuk kebutuhan pipeline AI
        mask_size = self.mask_size
        self.resized_square_mask_image = square_mask_image.resize((mask_size, mask_size))
        self.resized_square_image = square_image.resize((mask_size, mask_size))

        return self.resized_square_mask_image  # Kembalikan mask hasil resize
    
    # Fungsi untuk restore hasil generate ke gambar asli dengan bantuan mask transparan
    def restore_result(self, generated_image):
        square_length = self.square_length
        # Resize hasil generate ke ukuran square original
        generated_image = generated_image.resize((square_length, square_length))
        square_mask_image = self.square_mask_image
        # Crop area yang sudah di-generate sesuai posisi awal
        cropped_generated_image = generated_image.crop((self.square_start_x, self.square_start_y, self.square_end_x, self.square_end_y))
        cropped_square_mask_image = square_mask_image.crop((self.square_start_x, self.square_start_y, self.square_end_x, self.square_end_y))

        # Tempel hasil generate ke gambar asli dengan mask transparan
        restored_image = self.input_image.copy()
        restored_image.paste(cropped_generated_image, (self.origin_start_x, self.origin_start_y), cropped_square_mask_image)
        
        return restored_image
    
    # Versi restore tanpa mask (area hasil tempelkan langsung tanpa transparansi)
    def restore_result_v2(self, generated_image):
        square_length = self.square_length
        generated_image = generated_image.resize((square_length, square_length))
        cropped_generated_image = generated_image.crop((self.square_start_x, self.square_start_y, self.square_end_x, self.square_end_y))

        restored_image = self.input_image.copy()
        restored_image.paste(cropped_generated_image, (self.origin_start_x, self.origin_start_y))
        
        return restored_image