This Module will hide files inside images ( currenlty PNG ) and export the modified image to disk
The maximum size of file which can be hidden inside an image depends on the dimension of the image.
max_file_size = ( height_of_image * width_of_image * 6 / 8 ) bytesExample
Original Image
Modified Image
This image has 100k words hidden inside it!
How it works?
It is based on a simple principle that if we change the LSB ( Least Significant Bits ) of every Pixel, then the change will not be significant and will not be noticed by eyes.
So, this Module takes 2 bits of data from the file to be hidden and replaces the last 2 bits of one pixel with those 2 bits, and then move to next pixel. The maximum change in pixel can be 4 units, and the range of values in a PNG Image if (0,255), so this change will not be significant.
In a PNG Image, each pixel has 3 channels Red, Green and Blue. ( Some PNG Images have 1 or 4 channels, but this Program will convert them to 3 channels) A typical pixel in a PNG Image looks like :
a_pixel = (17,32,11) # (RED, GREEN, BLUE)max_file_size = ( height_of_image * width_of_image * 6 / 8 ) bytesbinary_data = 0b100111a_pixel = (0b10001, 0b100000, 0b1011) # binary representation of a_pixel values
# Let's change a_pixel's RED Channel
# 0b10001 -> 0b10010 ( First 2 bits are 10 )
a_pixel = (0b10010, 0b100000, 0b1011) # modified pixela_pixel = (0b10010, 0b100000, 0b1011)
# Let's change a_pixel's GREEN Channel
# 0b100000 -> 0b100001 ( The 2 bits are 01 )
a_pixel = (0b10010, 0b100001, 0b1011) # modified pixela_pixel = (0b10010, 0b100001, 0b1011)
# Let's change a_pixel's BLUE Channel
# 0b1011 -> 0b1011 ( The 2 bits are 11 ) ; Notice that the value wasn't changed this time
a_pixel = (0b10010, 0b100001, 0b1011) # pixel wasn't modified this timea_pixel = (0b10001, 0b100000, 0b1011) = (17, 32, 11)
a_pixel_with_data = (0b10010, 0b100001, 0b1011) = (18, 33, 11)
NOTE : The noise in the photo is increased and if we use any photo editing software and compare it with the original image, then this image will have much more noise than the original image.
Solution for this problem : Never ever upload/share the original image to internet
Todos
- Add support for JPEG Images
- Add encryption option
- Add auto detection of the name of file to be extracted