title: how to convert dzi files to multi-tile pyramidal tiff format
body: <p>In reference to the answer (<a href="https://stackoverflow.com/questions/53986084/how-to-convert-dzi-deep-zoom-files-to-full-image">how to convert dzi (deep zoom) files to full image</a>) </p>
  
  <p>I am a noob on this topic, please correct if I am wrong.</p>
  
  <p>I am trying to create a multi-tiled tiff from .dzi (deep zoom image) format, how I am doing is:</p>
  
  <p>(i) Pick the max level folder.</p>
  
  <p>(ii) Vertically Stitch all the n columns of m rows (m_n.jpeg, I am referring to the images saved in this format) as png images. So they are occupying quite a considerable amount of space.</p>
  
  <p>(iii) Finally, I horizontally merge all these vertical png images into a single full image png using pyvips.Image.write_to_file().</p>
  
  <p>(iv) Finally using vips im_save, I convert the full image png to tiff.</p>
  
  <p>My concern now is this process is taking almost 2 hours for it to make full image png for 30,000 base_tiles, and also it accounts to 10+ GB of size (Full Image png). </p>
  
  <p>Is there any better and faster way to do the .dzi to tiff conversion?</p>