'bits' data bits can be 8,7,6 or 5 default value is 8

With JPG images, two extra indexes are returned channels and bits. channels will be 3 for RGB pictures and 4 for CMYK pictures. bits is the number of bits for each color.

λ bits

'stop' stop bits can be 1 or 2 default value is 1

Beginning with PHP 4.3, bits and channels are present for other image types, too. However, the presence of these values can be a bit confusing. As an example, GIF always uses 3 channels per pixel, but the number of bits per pixel cannot be calculated for an animated GIF with a global color table.

Scans a, starting with bit start, towards more significant bits, until the first clear bit is found. Returns the index of the found bit.

Scans a, starting with bit start, towards more significant bits, until the first set bit is found. Returns the index of the found bit.

The 'b' character is ignored on all POSIX conforming systems which treat binary and text files in the same way. It is a good idea to specify the 'b' character whenever your stream is accessing data where the full 8 bits are important, so that your code will work when compiled on a system where the 'b' flag is important.