Binary image type in C -

if want create , work on binary image in c, data type should set image pixels? since binary image pixel has 2 values assuming need 1 bit each pixel , have use bit wise c functions, correct (most efficient) way binary image processing in c?

if case, how can allocate space image? malloc allocates space in units of bytes if not mistaking.

for clarification: have 32bit float image (with known size), apply threshold , save thresholding result binary can label separate components.

using single bit per pixel memory-efficient least time-efficient, since accessing pixels requires bitwise operations. if wanted this, have malloc((numpixels + 7)/8), i.e. round allocation size nearest byte.

it better balance of memory , space considerations store image chars. internal representation thresholded images in opencv, example.