Module ffi.koptcontext
Leptonica cheatsheet:
-- Data structures: PIX -- basic data structure - stores image BOX -- stores rectangle (x, y, w, h) BOXA -- array of BOX NUMA -- array of numbers
-- Functions: -- note that all of them take/return pointers, or null/nil on failure pixDestroy(pix) -- free memory from PIX boxDestroy(box) -- free memory from BOX selDestroy(sel) -- free memory from SEL boxaDestroy(boxa) -- free memory from BOXA numaGetIValue(nai, counter_w, counter_l) -- returns int value from NUMA pixGetWidth(pix) -- return pix width pixGetHeight(pix) -- return pix height pixConvertTo32(pix) -- converts pix to 32bpp boxaCombineOverlaps(boxa) -- return intersection of all box in a boxa boxCreate(x, y, w, h) -- create box with given dimensions boxaGetCount(boxa) -- get number of elements in boxa array -- get element from BOXA flag can be C.L_COPY (creates new copy) or -- C.L_CLONE (returns ref-counted handle) boxaGetBox(boxa, index, flag) -- add box to boxa array, flag can be C.L_INSERT, or C.L_COPY boxaAddBox(boxa, box, flag) -- adjust box's size by given deltas and write it to boxd boxAdjustSides(boxd, boxs, d_left, d_right, d_top, d_bottom) -- returns boxa where each element intersects with box, -- or is removed if it doesn't intersect boxaClipToBox(boxa, box) -- returns intersection of both box, or null if they don't intersect boxOverlapRegion(box, box) -- returns new black-white PIX, -- if the source pixel is < threshold, -- resulting pixel is 1 (black), -- otherwise 0 (white) pixThresholdToBinary(pix, threshold) -- returns 0 on success and 1 on failure, output_* are PIX pixGetRegionsBinary(input_pix, output_halftonemask, output_textline_mask, output_textblock_mask, debug) -- draw boxa elements in random color with given width pixDrawBoxaRandom(pix, boxa, width) -- creates png from pix, useful for debugging pixWritePng(path, pix, gamma) -- multiplies box part of pixs by color and writes it to pixd pixMultiplyByColor(pixd, pixs, box, color) -- converts float_array to NUMA, flag is either C.L_INSERT or C.L_COPY numaCreateFromFArray(float_array, size, flag)