How to insert image in pdf using Java

I am trying to create pdfs with Java. I do not want to use libraries like ITextPdf but want to generate the raw code of the pdf with Java. I got the basics down and am able to create some pdfs. The thing I am struggling with is inserting images in the pdf. As far as I understand JPEG's are the easiest ones to use since the raw data can be inserten in de the pdf. When I am trying this, it does not work however. I am reading the JPEG data with java ad inserting this in the pdf.

The generated PDF code looks like this:

%PDF-1.7

1 0 obj
  <<

    /Type /Catalog
    /Pages 2 0 R
  >>
endobj

2 0 obj
  <<

    /Type /Pages
    /Count 1
    /Kids [3 0 R]
  >>
endobj

---------------------------------------------

3 0 obj
  <<

    /Type /Page
    /Parent 2 0 R
    /MediaBox [0 0 595 842]
    /Contents [5 0 R]
    /Resources
    <<

    /XObject
      <<
        /Im1 4 0 R
      >>
    >>
  >>
endobj


5 0 obj 
  <<
    /Length 35 
  >> 
  stream 
    q 
    209 0 0 241 0 0 cm
    /Im1 Do 
    Q 
  endstream 
endobj

4 0 obj
  <<

    /Type /XObject
    /Filter /DCTDecode
    /Length 8000
    /ColorSpace /DeviceRGB
    /Height 241
    /Width 209
    /Subtype /Image
    /BitsPerComponent 8
  >>
    stream
      ***
    endstream
endobj

---------------------------------------------

trailer
  <<

    /Root 1 0 R
    /Size 5
  >>
%%EOF

the stream data marked as "***" are the image bytes I got by using (this is inserted in the file by java):

java.nio.file.Files.readAllBytes(Paths.get(image.getPath())))

When viewig the pdf it does not display the image. The image I used can be found here: https://rp-do-not-delete.s3.eu-central-1.amazonaws.com/download.jpeg.

I read the image width, height and byte length by reading the BufferedImage.getData() data, so, as far as I know, it should be correct.

Does anyone know what is wrong or what way I can approach this problem? Feel free to ask additional information like Java code I used etc.

Your code is generally PURR-effect. Here is the result when code and image are added together correctly in MS Notepad and image via command line. It is short of one essential feature (the xref table before the trailer) but Acrobat Reader will ignore that and write its own.

Personally I tend to abbreviate the entries as it easier to see what is happening inside the PDF.

%PDF-1.7

1 0 obj <</Type/Catalog/Pages 2 0 R>> endobj
2 0 obj <</Type/Pages/Count 1/Kids [3 0 R]>> endobj
3 0 obj <</Type/Page/Parent 2 0 R/MediaBox [0 0 595 842]/Contents [5 0 R]/Resources<</XObject<</Im1 4 0 R>>>>>> endobj
5 0 obj <</Length 35>>
stream 
q 
209 0 0 241 0 0 cm
/Im1 Do 
Q 

endstream 
endobj

4 0 obj <</Type/XObject/Filter/DCTDecode/Length 8000/ColorSpace/DeviceRGB/Height 241/Width 209/Subtype/Image/BitsPerComponent 8>>
stream
*** Image goes here
endstream
endobj

trailer <</Root 1 0 R/Size 5>>
%%EOF

In that state it will be 8,527 bytes( so only 527 more than the raw image), However Acrobat READER will save it as 12,665 bytes because it adjusts to be more compliant with web usage etc.

Thus we see its totally different (not all necessarily better) so now starts

%PDF-1.7
%âãÏÓ
7 0 obj
<</Linearized 1/L 12665/O 9/E 9017/N 1/T 12376/H [ 435 131]>>
endobj
                     
12 0 obj
<</DecodeParms<</Columns 3/Predictor 12>>/Filter/FlateDecode/ID[<84AE98C0D1CB3C4D9543B24450B2D64C><84AE98C0D1CB3C4D9543B24450B2D64C>]/Index[7 7]/Info 6 0 R/Length 36/Prev 12377/Root 8 0 R/Size 14/Type/XRef/W[1 2 0]>>stream
hÞbbd`b`Rcb`°ab`œ
¤C™þJ Ùö  0Ä
endstream
endobj
startxref
0
%%EOF
        
13 0 obj
<</Filter/FlateDecode/I 66/Length 52/S 36>>stream
hÞb```f``|Ï 
Ç0ŠBx™ì ¢úû4#Ï0 ¡¹,
endstream
endobj
8 0 obj
<</Metadata 1 0 R/Pages 5 0 R/Type/Catalog>>

!!!

To avoid such adjustments you need to include a xref of your own. For a very rough example in JScript see below.

Note:- The copy and paste here will break the binary.

var ByteStream = new ActiveXObject("ADODB.Stream");
ByteStream.Type = 2; // Writer
ByteStream.Charset = "Windows-1252"; //Best for PDF writer
var BS = ByteStream; // Abreviate for ease of edit
BS.Open();
BS.Position = 0;

BS.WriteText("%PDF-1.0\n");
BS.WriteText("%Åѧ¡\n");

BS.WriteText("1 0 obj <</Type/Catalog/Pages 2 0 R>> endobj\n");
BS.WriteText("2 0 obj <</Type/Pages/Count 1/Kids[3 0 R]>> endobj\n");
BS.WriteText("3 0 obj <</Type/Page/MediaBox[0 0 144 144]/Rotate 0/Resources<</XObject<</Img0 4 0 R>>>>/Contents 5 0 R/Parent 2 0 R>> endobj\n");
BS.WriteText("4 0 obj <</Type/XObject/Subtype/Image/Height 25/Width 24/BitsPerComponent 1/Length 75/ColorSpace/DeviceGray>> stream\n");
BS.WriteText('ÿÿÿÿÿÿÀmß[}ÑoEÑ[EÑqEßE}ÀUÿñÿÁ«Á¬ÛZcýÖÇÈ"}ÿÕïÀMsß`§Ñ]9ÑNÑE·ßLÇÀA[ÿÿÿÿÿÿ');
BS.WriteText("\nendstream\nendobj\n");
var Pos1 = "000000000"+BS.Position
BS.WriteText("5 0 obj <</Length 101>> stream\n");
BS.WriteText("q\n1 0 0 -1 18 54 cm\n35 0 0 -36 0 36 cm\n/Img0 Do\nQ\nq\n1 0 0 -1 71 144 cm\n70 0 0 -72 0 72 cm\n/Img0 Do\nQ\n");
BS.WriteText("\nendstream\nendobj\n\n");
var Pos2 = BS.Position
BS.WriteText("xref\n0 6\n");
BS.WriteText("0000000000 00001 f \n0000000015 00000 n \n0000000060 00000 n \n0000000111 00000 n \n0000000237 00000 n \n"+Pos1.slice(-10)+" 00000 n \n");
BS.WriteText("\ntrailer\n<</Size 6/Info<</Producer(JScrip2pdf)>>/Root 1 0 R>>\nstartxref\n"+Pos2+"\n%%EOF\n");

BS.SaveToFile("HelloWorldB&W.pdf", 2);
BS.Close();

A simple means to fix such missing trailer is often solved using MuPDF-GL but that is windows only, so use command line MuTool for cross platform cleaning.

It too will alter the file to a cleaner 8,653 bytes format (so very few additions)

%PDF-1.7
%µ¶

1 0 obj
<</Type/Catalog/Pages 2 0 R>>
endobj

2 0 obj
<</Type/Pages/Count 1/Kids[3 0 R]>>
endobj

3 0 obj
<</Type/Page/Parent 2 0 R/MediaBox[0 0 595 842]/Contents 5 0 R/Resources<</XObject<</Im1 4 0 R>>>>>>
endobj

4 0 obj
<</Type/XObject/Filter/DCTDecode/Length 8000/ColorSpace/DeviceRGB/Height 241/Width 209/Subtype/Image/BitsPerComponent 8>>
stream
ÿØÿà JFIF      ÿÛ „

blah blah CAT Image bytes

NI dI$¦’I$ ’I$ ’I$Ç(\’H'¨+h’I/¡ã±ŒÐ¨Ÿ¡I%Äû:Y]Û+øBI-}è"Ý–³€¦VÁìž^‚‰ÍI%Ôs©$„k{@I$’I% ÿÙ
endstream
endobj

5 0 obj
<</Length 35>>
stream
q
209 0 0 241 0 0 cm
/Im1 Do
Q
q
Q

endstream
endobj

xref
0 6
0000000000 65536 f 
0000000016 00000 n 
0000000062 00000 n 
0000000114 00000 n 
0000000231 00000 n 
0000008387 00000 n 

trailer
<</Size 6/Root 1 0 R>>
startxref
8471
%%EOF