How does it happen

Question

i read the raw data of a pgm image file and got the following output
P5
# created by ilidss
512 512
255
162
160
161
165
65533
164
162
165
But 65533 is impossible because the max value of a pixel is 255. the following is the rough code:
bufferredreader in = ...... //bufferedreader read data from lena.pgm
for (int i=0; i<4;i++) system.out.println(in.readLine());
//read four-line header
for (int i=0; i<8;i++) system.out.println(in.read());
//read raw data which is binary value according to magic line indicating "P5"
Could anyone tell me what's going on!

Answer 1

thank you indeed!
the PGM image format is composed of tow parts: header and data
header includes three lines at least 3 lines
1.magic line: can be P5 OR P2.P5 means the data is binary representation. P2 indicates the image data is ascii text format.
2.dimension: eg. 8 8 means 8*8 totally 64 pixels
3.max pixel value: every pixel value should be less than it
4.comment starting with #, it is optional and can be everywhere. it cannot more than 70 charactors.
data is the raw image data
an example
P2 # ascii text format rather than binary
8 4 # 32 pixel
15
0 0 0 0 0 0 15 15
15 15 0 0 0 0 0 0
0 0 11 11 0 0 0 0
0 0 0 0 13 13 0 0
thank you very much. in my case, i am reading a P5 image which contains binary data