New image on the same place of a old one.

[José Rodolfo Carrijo de Freitas]

Hello,

 

I’ve been trying to make some changes on the size of pdfs.

My first step on my strategy was to extract all images from the pdf and
compact them.

I made it successfully.

Now, What I need to do is to replace the image ‘I’ with the compressedImage
‘CI’ using the same graphicstate, so visually the pdf would be the same(or
almost), the difference: with lower quality images.

 

I tried to createOutputStream on the image and read the stream of the
compacted one.

 

I tried to drawImage with the contentStream, but it seemed that it printed
both images. And besides, I didn’t manage a way to get the graphicstate of
the “old” image.

 

I tried to set a new Image, which obviously would not work, but I had to
try, just in case.

 

Now What I’m trying to do:

 

Pass the dictionary tree for a new PDDocument and replace the image
resources with the compacted files, and save this new document.

However I don’t know how I can get this tree.

 

So I was wondering if you guys can give me some light.

 

Thank you.