pymupdf.Page.replace_image() will save an image stream file 2 times #4327

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1. JorjMcKie commented on Feb 25, 2025

   

   JorjMcKie

   on Feb 25, 2025

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   I don't understand what you are actually doing: please provide your PDF and your script.
   We cannot deal with issues that do not follow the requirements as stated in the bug issue form.

   One intermediate comment though:
   When saving the PDF after replacing / deleting an image make sure to use garbage collection and compression options so that the old data is removed! Recommended is using doc.ez_save().
2. JorjMcKie

   added

   example required

   Waiting for information

   on Feb 25, 2025
3. Muolae commented on Feb 25, 2025

   

   Muolae

   on Feb 25, 2025

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   I want to replace the original image in the pdf file with a smaller image, my program extracts each image in the file, then uses a compression function to reduce their size, and then replaces the original image. But I found that for example, if I delete all the pictures directly, the resulting file size is 1MB, and if I replace the original picture with a total size of 2MB, I get a file with a size of 5MB. I think the reasonable size is 3MB.This means that these pictures store two copies of the same data in a pdf file.Thank you for your reply
   ` for page in doc.pages():
   imageList = page.get_images()

       for imginfo in imageList:
           xref = imginfo[0]  # 获取图像的 xref
           image_info = doc.extract_image(xref)
   
           # 保存图像到文件
           new_name = f"./src/temp/image_{xref}.{image_info['ext']}"
           with open(new_name, "wb") as img_file:
               img_file.write(image_info["image"])
           img = imgopen(new_name)
           pix_size += img.height * img.width * 3 // 1024
           img_size+=os.path.getsize(new_name) / 1024
   
           loc = page.get_image_rects(imginfo)
           # doc._deleteObject(imginfo[0])
           page.delete_image(xref)
           compressed_image_name = new_name.replace(new_name.split(".")[-1], 'jpg')
           picCompress.compress_by_quality(new_name, compressed_image_name, quality=15)
           zimg_size+=os.path.getsize(compressed_image_name)/1024
           # page.insert_image(loc[0], filename=compressed_image_name,overlay=False)
           page.replace_image(xref, filename=compressed_image_name)
           # my_replace(page,xref,filename=compressed_image_name)
       now_page += 1
       # ws.send("reg:" + str(int(100 * now_page / page_number)))
   # print("图片面积大小:", pix_size, "KB")
   # print("图片实际大小:", img_size, "KB")
   # print("图片压缩大小:", zimg_size, "KB")
   # 计算无图片文件大小
   doc.ez_save(filename='./out/out.pdf')`
   
4. JorjMcKie commented on Feb 25, 2025

   

   JorjMcKie

   on Feb 25, 2025

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   I see no issue here, but rather a request for help. Moving this to "Discussions".
5. pymupdf

   locked and limited conversation to collaborators on Feb 25, 2025
6. JorjMcKie

   converted this issue into a discussion #4328 on Feb 25, 2025