透過 Java 的 Python 從簡報形狀擷取影像
概述
簡報中的影像可能以多種形狀類型出現:普通的圖片框、套用到形狀的圖片填充、OLE 物件的預覽圖、影片或音訊框的縮圖、Zoom 圖片,或是嵌入在表格、圖表與 SmartArt 形狀內的圖片。Aspose.Slides 會將這些影像存放在簡報的影像集合中,透過 ImageCollection 與 PPImage 物件公開。
如果只需要匯出簡報中嵌入的每個影像資源,可遍歷 Presentation.getImages。本文聚焦於另一項任務:遍歷形狀以找出投影片上使用影像的地方,讓儲存的檔案能保留有用的上下文資訊,如投影片編號、形狀位置與來源類型(圖片框、填充影像、媒體預覽、OLE 預覽或 Zoom 影像)。
共用輔助函式
將下列共用輔助函式儲存於 image_helpers.py,與範例腳本放在同一目錄下。這可讓範例保持簡潔。save_original_image 會寫入原始嵌入位元組、依 MIME 型別選擇安全的副檔名,並透過 SHA-256 雜湊跳過重複的影像位元組。
from pathlib import Path
import hashlib
import re
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import FillType, GroupShape, ImageFormat
def save_original_image(image, output_directory, file_name_base, saved_image_hashes):
image_data = bytes(image.getBinaryData())
image_hash = hashlib.sha256(image_data).hexdigest()
if image_hash in saved_image_hashes:
return False
saved_image_hashes.add(image_hash)
extension = get_extension_from_content_type(image.getContentType())
output_file = Path(output_directory) / f"{file_name_base}.{extension}"
output_file.write_bytes(image_data)
return True
def save_image_as_png(image, output_directory, file_name_base):
output_file = Path(output_directory) / f"{file_name_base}.png"
output_image = image.getImage()
try:
output_image.save(str(output_file), ImageFormat.Png)
finally:
output_image.dispose()
def get_picture_fill_image(fill_format):
if fill_format is None or fill_format.getFillType() != FillType.Picture:
return None
return fill_format.getPictureFillFormat().getPicture().getImage()
def enumerate_shapes(shapes, prefix, include_grouped_shapes):
shape_references = []
for shape_index in range(shapes.size()):
shape = shapes.get_Item(shape_index)
shape_name_part = f"{prefix}_shape_{shape_index + 1}"
shape_references.append((shape, shape_name_part))
if include_grouped_shapes and isinstance(shape, GroupShape):
child_shapes = shape.getShapes()
child_references = enumerate_shapes(child_shapes, shape_name_part, include_grouped_shapes)
shape_references.extend(child_references)
return shape_references
def get_extension_from_content_type(content_type):
if content_type is None or not str(content_type).strip():
return "bin"
media_type = str(content_type).split(";")[0].strip().lower()
extensions = {
"image/jpeg": "jpg",
"image/png": "png",
"image/gif": "gif",
"image/bmp": "bmp",
"image/tiff": "tiff",
"image/x-emf": "emf",
"image/emf": "emf",
"image/x-wmf": "wmf",
"image/wmf": "wmf",
"image/svg+xml": "svg",
}
if media_type in extensions:
return extensions[media_type]
if media_type.startswith("image/"):
return re.sub(r"[^A-Za-z0-9._-]", "_", media_type[len("image/"):])
return "bin"
從圖片框擷取影像
使用此方法擷取以獨立物件插入的圖片。PictureFrame 可透過 getPictureFormat、getPicture 與 getImage 取得其圖片,回傳的物件為 PPImage。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, PictureFrame
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "extracted-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, False)
for shape, name_part in shape_references:
if isinstance(shape, PictureFrame):
picture_frame = shape
image = picture_frame.getPictureFormat().getPicture().getImage()
save_original_image(image, output_directory, name_part, saved_image_hashes)
finally:
presentation.dispose()
從填充圖片的形狀擷取影像
形狀可以使用圖片作為填充。先檢查形狀的填充類型:如果不是 FillType.Picture,就沒有可擷取的圖片。以下範例處理 AutoShape 物件,並透過 PPImage.getImage 以 PNG 格式儲存每張圖片。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, AutoShape
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "shape-fill-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, False)
for shape, name_part in shape_references:
if isinstance(shape, AutoShape):
auto_shape = shape
fill_format = auto_shape.getFillFormat()
image = get_picture_fill_image(fill_format)
if image is not None:
save_image_as_png(image, output_directory, name_part)
finally:
presentation.dispose()
從 OLE 物件框擷取預覽影像
OleObjectFrame 可以有 PowerPoint 用於投影片預覽的代用圖片。此影像可透過 getSubstitutePictureFormat、getPicture 與 getImage 取得。擷取此圖片會得到預覽影像,而非嵌入的 OLE 套件內容。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, OleObjectFrame
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "ole-preview-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, False)
for shape, name_part in shape_references:
if isinstance(shape, OleObjectFrame):
ole_object_frame = shape
image = ole_object_frame.getSubstitutePictureFormat().getPicture().getImage()
if image is not None:
file_name_base = name_part + "_ole_preview"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
finally:
presentation.dispose()
從影片框擷取預覽影像
VideoFrame 也可以在 getPictureFormat、getPicture 與 getImage 中儲存預覽圖。這是投影片上顯示的海報或縮圖,並非從影片串流解碼的畫格。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, VideoFrame
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "video-preview-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, False)
for shape, name_part in shape_references:
if isinstance(shape, VideoFrame):
video_frame = shape
image = video_frame.getPictureFormat().getPicture().getImage()
if image is not None:
file_name_base = name_part + "_video_preview"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
finally:
presentation.dispose()
從音訊框擷取預覽影像
AudioFrame 可以在 getPictureFormat、getPicture 與 getImage 中儲存縮圖。這是在投影片上為音訊物件顯示的圖示。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, AudioFrame
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "audio-preview-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, False)
for shape, name_part in shape_references:
if isinstance(shape, AudioFrame):
audio_frame = shape
image = audio_frame.getPictureFormat().getPicture().getImage()
if image is not None:
file_name_base = name_part + "_audio_preview"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
finally:
presentation.dispose()
從 Zoom 物件擷取影像
ZoomFrame 與 SectionZoomFrame 形狀可以使用自訂影像。請從 Zoom 框讀取 getZoomImage。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, SectionZoomFrame, ZoomFrame
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "zoom-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, False)
for shape, name_part in shape_references:
if isinstance(shape, ZoomFrame):
zoom_frame = shape
image = zoom_frame.getZoomImage()
if image is not None:
file_name_base = name_part + "_zoom"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
continue
if isinstance(shape, SectionZoomFrame):
section_zoom_frame = shape
image = section_zoom_frame.getZoomImage()
if image is not None:
file_name_base = name_part + "_section_zoom"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
continue
finally:
presentation.dispose()
從摘要 Zoom 框擷取影像
SummaryZoomFrame 同樣是一種形狀。其各節項目可使用自訂影像,透過每個摘要 Zoom 節的 getZoomImage 方法取得。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, SummaryZoomFrame
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "summary-zoom-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, False)
for shape, name_part in shape_references:
if isinstance(shape, SummaryZoomFrame):
summary_zoom_frame = shape
section_count = summary_zoom_frame.getSummaryZoomCollection().size()
for section_index in range(section_count):
section = summary_zoom_frame.getSummaryZoomCollection().get_Item(section_index)
image = section.getZoomImage()
if image is not None:
display_index = section_index + 1
file_name_base = name_part + "_summary_zoom_" + str(display_index)
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
finally:
presentation.dispose()
從表格形狀擷取影像
Table 是一種形狀。表格中的影像通常以圖片填充的方式儲存在表格儲存格中。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, Table
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "table-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, True)
for shape, name_part in shape_references:
if isinstance(shape, Table):
table = shape
row_count = table.getRows().size()
column_count = table.getColumns().size()
for row_index in range(row_count):
for column_index in range(column_count):
cell = table.get_Item(column_index, row_index)
fill_format = cell.getCellFormat().getFillFormat()
image = get_picture_fill_image(fill_format)
if image is not None:
display_row = row_index + 1
display_column = column_index + 1
file_name_base = name_part + "_cell_" + str(display_row) + "_" + str(display_column)
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
finally:
presentation.dispose()
從圖表形狀擷取影像
Chart 是一種形狀。下列範例從圖表區域的圖片填充中擷取影像。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, Chart
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "chart-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, True)
for shape, name_part in shape_references:
if isinstance(shape, Chart):
chart = shape
fill_format = chart.getFillFormat()
image = get_picture_fill_image(fill_format)
if image is not None:
file_name_base = name_part + "_chart_area"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
finally:
presentation.dispose()
從 SmartArt 形狀擷取影像
SmartArt 物件是一種形狀。依據 SmartArt 版面配置,影像可能儲存在節點項目的子彈填充或節點形狀的填充格式中。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, SmartArt
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "smartart-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, True)
for shape, name_part in shape_references:
if isinstance(shape, SmartArt):
smart_art = shape
node_count = smart_art.getAllNodes().size()
for node_index in range(node_count):
node = smart_art.getAllNodes().get_Item(node_index)
bullet_fill_format = node.getBulletFillFormat()
bullet_image = get_picture_fill_image(bullet_fill_format)
if bullet_image is not None:
display_node = node_index + 1
file_name_base = name_part + "_smartart_node_" + str(display_node) + "_bullet"
save_original_image(bullet_image, output_directory, file_name_base, saved_image_hashes)
node_shape_count = node.getShapes().size()
for node_shape_index in range(node_shape_count):
node_shape = node.getShapes().get_Item(node_shape_index)
fill_format = node_shape.getFillFormat()
image = get_picture_fill_image(fill_format)
if image is not None:
display_node = node_index + 1
display_node_shape = node_shape_index + 1
file_name_base = name_part + "_smartart_node_" + str(display_node) + "_shape_" + str(display_node_shape)
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
finally:
presentation.dispose()
包含群組形狀內的影像
群組形狀擁有自己的形狀集合。共用的 enumerate_shapes 輔助函式提供 include_grouped_shapes 參數。當需要檢查 GroupShape 內的形狀時,將其設為 True。下列範例從圖片框、填充圖片的形狀、OLE 物件預覽、影片框縮圖與音訊框縮圖中擷取影像。若要同時包含表格、圖表、SmartArt 與摘要 Zoom 的影像,可在相同的遞迴形狀遍歷中重複使用前述各段的專門擷取邏輯。
from pathlib import Path
import jpype
import asposeslides
if not jpype.isJVMStarted():
jpype.startJVM()
from asposeslides.api import Presentation, AudioFrame, AutoShape, OleObjectFrame, PictureFrame, VideoFrame
from image_helpers import enumerate_shapes, get_picture_fill_image, save_image_as_png, save_original_image
input_path = "sample.pptx"
output_directory = Path.cwd() / "all-shape-images"
output_directory.mkdir(parents=True, exist_ok=True)
saved_image_hashes = set()
presentation = Presentation(input_path)
try:
slide_count = presentation.getSlides().size()
for slide_index in range(slide_count):
slide = presentation.getSlides().get_Item(slide_index)
slide_number = slide.getSlideNumber()
slide_prefix = "slide_" + str(slide_number)
shapes = slide.getShapes()
shape_references = enumerate_shapes(shapes, slide_prefix, True)
for shape, name_part in shape_references:
if isinstance(shape, OleObjectFrame):
ole_object_frame = shape
image = ole_object_frame.getSubstitutePictureFormat().getPicture().getImage()
if image is not None:
file_name_base = name_part + "_ole_preview"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
continue
if isinstance(shape, VideoFrame):
video_frame = shape
image = video_frame.getPictureFormat().getPicture().getImage()
if image is not None:
file_name_base = name_part + "_video_preview"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
continue
if isinstance(shape, AudioFrame):
audio_frame = shape
image = audio_frame.getPictureFormat().getPicture().getImage()
if image is not None:
file_name_base = name_part + "_audio_preview"
save_original_image(image, output_directory, file_name_base, saved_image_hashes)
continue
if isinstance(shape, PictureFrame):
picture_frame = shape
image = picture_frame.getPictureFormat().getPicture().getImage()
save_original_image(image, output_directory, name_part, saved_image_hashes)
continue
if isinstance(shape, AutoShape):
auto_shape = shape
fill_format = auto_shape.getFillFormat()
image = get_picture_fill_image(fill_format)
if image is not None:
save_original_image(image, output_directory, name_part, saved_image_hashes)
finally:
presentation.dispose()
邊緣情況與實務說明
- 重複影像: 多個形狀可能參考同一影像,或是不同影像卻具有相同的位元組。若希望每個唯一影像只產生一個輸出檔案,請在寫檔前對 PPImage.getBinaryData 計算雜湊。
- 原始資料 vs 轉換輸出: 儲存 PPImage.getBinaryData 會保留 JPEG、PNG、GIF、SVG、EMF 或 WMF 等嵌入的原始資料。透過
save儲存 PPImage.getImage 則適合需要統一輸出格式的情況。 - 不支援的填充類型: 實心、漸層、圖樣及無填充的形狀不含圖片填充。讀取前請先檢查 FillType。
- 群組形狀: 投影片的頂層形狀集合不會自動展平群組。當群組內容重要時,請遞迴檢查 GroupShape.getShapes。
- OLE 物件預覽: OleObjectFrame 可能透過 getSubstitutePictureFormat 暴露預覽影像,但該影像僅為投影片預覽,並非 OLE 物件內嵌的檔案本身。
- 影片框縮圖: VideoFrame 可能透過 getPictureFormat 暴露預覽影像,該影像僅為投影片上顯示的海報,並非從影片串流解碼的畫格。
- 音訊框縮圖: AudioFrame 可能透過 getPictureFormat 暴露圖示或縮圖;這並非嵌入的音訊資料本身。
- Zoom 影像: 投影片 Zoom、節段 Zoom 與摘要 Zoom 形狀可透過 getZoomImage 取得自訂的 PPImage 物件。
- 巢狀形狀模型: 表格、圖表與 SmartArt 物件皆實作 Shape,但其影像常存於巢狀的儲存格、圖表元素或 SmartArt 節點格式物件中。
- 裁剪或變形的圖片: 取得 PPImage 只會得到儲存的影像資源,並不會套用形狀所做的裁剪、透明度、重新著色、旋轉或其他視覺效果。
常見問題
我能否在不裁剪、套用效果或形狀變形的情況下擷取原始影像?
可以。存取 PPImage 物件,並將 PPImage.getBinaryData 寫入磁碟,即可保留簡報中儲存的原始編碼影像,而非投影片上呈現的樣子。
我能否將所有擷取的影像匯出為 PNG?
可以。使用 PPImage.getImage 取得影像物件,然後以 save 搭配 ImageFormat.Png 儲存。這會將輸出轉換為 PNG,可能不會保留原始檔案類型或向量資料。
如何避免重複儲存同一影像?
對 PPImage.getBinaryData 計算雜湊,將雜湊值保存在集合中。若新影像的雜湊已存在,則跳過儲存或記錄為同一輸出檔案的另一個參考。
為什麼有些形狀不會產生影像?
圖片框、填充圖片的形狀、OLE 物件框、媒體框、Zoom 框、表格、圖表與 SmartArt 物件都可能參考影像。某些形狀類型會透過巢狀的格式物件暴露影像,因此僅檢查 getPictureFormat 或形狀的 getFillFormat 並不足以抓到所有情況。
我能否擷取影片框顯示的縮圖?
可以。使用 VideoFrame 讀取 getPictureFormat、getPicture 與 getImage。此操作會擷取隨影片框儲存的海報影像,而非從影片檔案中產生的畫格。
我要如何判斷哪些形狀使用了簡報影像集合中的特定影像?
Aspose.Slides 不會從 PPImage 反向追蹤至形狀。遍歷時建立映射:每當發現影像參考時,記錄投影片編號、形狀路徑以及影像的雜湊或集合項目。
我能否擷取嵌入在 OLE 物件內的影像,例如附加的文件?
您可以從 OleObjectFrame.getSubstitutePictureFormat 取得 OLE 物件的投影片預覽圖。但該預覽圖並非嵌入的文件本身。若要擷取內嵌檔案中的影像,需要先抽出 OLE 資料,然後使用該檔案類型的工具進一步檢查。