How to read image header information and display it

[shamboo]

HI every one ,

how to read image header information

I have Png images which i read into the database as blob files. Now i want to get the header information from that blob(binary content).I would appreciate if some one could help me. As a try i used stream_get_meta_data function but i think it doesn't work properly.

Could some one provide me example code or tell me how to do it.

Thanks
Shamboo

[ReveL]

have you tried:
exif_read_data -- Reads the EXIF headers from JPEG or TIFF

i think it will PNG aswel. you might need to write te file to disk first. you could use tmpfile() for that

[shamboo]

I need to know how can i calculate pixel intensities png images,

I have blob data of png images in the table and i need to calcuate intensities of all the pixels of that blobed images.

I would appreciate if some one could help me

Thanks
Shamboo