使用ReportLab（Python）的PDF文檔中的PDF圖像

Question

我將matplotlib中的一些圖保存爲pdf格式，因爲它似乎提供了更好的質量。如何使用ReportLab將PDF圖像包含到PDF文檔中？便捷方法Image（文件路徑）不適用於此格式。

謝謝。從reportlab.graphics

Answer 1

採用進口renderPDF

Answer 2

根據ReportLab's FAQ這是唯一可能與ReportLab的PLUS：

我可以使用矢量圖形在我的PDF文件？

不，開源軟件包不會做 這個。的PageCatcher（見前面的 答案），讓您輕鬆 通過保存 爲PDF，然後用它究竟 ，你會映像文件包含任何矢量圖像，並報告 標記語言接受PDF文件 以JPG一起， GIF和PNG。

更新：我沒有研究過這一段時間，但on the page of pdfrw它說：

pdfrw可以讀寫PDF文件，也​​可以用來讀取PDF中其可以然後在reportlab中使用。

Answer 3

您可以ReportLab的一起運用之妙pdfrw包，並用它來傳遞的matplotlib人物類文件對象直接進入一個流動性：

這是回答過，但我想給一個小例子，在這裏，還請看看這裏：https://stackoverflow.com/a/13870512/4497962

from io import BytesIO 
import matplotlib.pyplot as plt 
from pdfrw import PdfReader, PdfDict 
from pdfrw.buildxobj import pagexobj 
from pdfrw.toreportlab import makerl 
from reportlab.platypus import Flowable 
from reportlab.lib.enums import TA_JUSTIFY,TA_LEFT,TA_CENTER,TA_RIGHT 

class PdfImage(Flowable): 
    """ 
    PdfImage wraps the first page from a PDF file as a Flowable 
    which can be included into a ReportLab Platypus document. 
    Based on the vectorpdf extension in rst2pdf (http://code.google.com/p/rst2pdf/) 

    This can be used from the place where you want to return your matplotlib image 
    as a Flowable: 

     img = BytesIO() 

     fig, ax = plt.subplots(figsize=(canvaswidth,canvaswidth)) 

     ax.plot([1,2,3],[6,5,4],antialiased=True,linewidth=2,color='red',label='a curve') 

     fig.savefig(img,format='PDF') 

     return(PdfImage(img)) 

    """ 

    def __init__(self, filename_or_object, width=None, height=None, kind='direct'): 
     # If using StringIO buffer, set pointer to begining 
     if hasattr(filename_or_object, 'read'): 
      filename_or_object.seek(0) 
      #print("read") 
     self.page = PdfReader(filename_or_object, decompress=False).pages[0] 
     self.xobj = pagexobj(self.page) 

     self.imageWidth = width 
     self.imageHeight = height 
     x1, y1, x2, y2 = self.xobj.BBox 

     self._w, self._h = x2 - x1, y2 - y1 
     if not self.imageWidth: 
      self.imageWidth = self._w 
     if not self.imageHeight: 
      self.imageHeight = self._h 
     self.__ratio = float(self.imageWidth)/self.imageHeight 
     if kind in ['direct','absolute'] or width==None or height==None: 
      self.drawWidth = width or self.imageWidth 
      self.drawHeight = height or self.imageHeight 
     elif kind in ['bound','proportional']: 
      factor = min(float(width)/self._w,float(height)/self._h) 
      self.drawWidth = self._w*factor 
      self.drawHeight = self._h*factor 

    def wrap(self, availableWidth, availableHeight): 
     """ 
     returns draw- width and height 

     convenience function to adapt your image 
     to the available Space that is available 
     """ 
     return self.drawWidth, self.drawHeight 

    def drawOn(self, canv, x, y, _sW=0): 
     """ 
     translates Bounding Box and scales the given canvas 
     """ 
     if _sW > 0 and hasattr(self, 'hAlign'): 
      a = self.hAlign 
      if a in ('CENTER', 'CENTRE', TA_CENTER): 
       x += 0.5*_sW 
      elif a in ('RIGHT', TA_RIGHT): 
       x += _sW 
      elif a not in ('LEFT', TA_LEFT): 
       raise ValueError("Bad hAlign value " + str(a)) 

     #xobj_name = makerl(canv._doc, self.xobj) 
     xobj_name = makerl(canv, self.xobj) 

     xscale = self.drawWidth/self._w 
     yscale = self.drawHeight/self._h 

     x -= self.xobj.BBox[0] * xscale 
     y -= self.xobj.BBox[1] * yscale 

     canv.saveState() 
     canv.translate(x, y) 
     canv.scale(xscale, yscale) 
     canv.doForm(xobj_name) 
     canv.restoreState() 

Answer 4

您可以從matplotlib使用SVG出口和使用svglib Python庫包括矢量圖形生成的ReportLab的PDF文件。 svglib需要一個svg文件並製作一個可以直接在reportlab中使用的繪圖對象。

另請參見此問題以瞭解更多詳細信息：Generating PDFs from SVG input