FlashAir-libBMP

Read and write 24bpp or 16bpp uncompressed windows bitmaps from pure Lua.

update at 2019/3/21:Suport 64K part load to save memory and direction(x,y) to udside down

Requirement

This is SoraMame library for BMP.
SoraMame series are IoT gadgets of FlashAir.

Tested on FlashAir W-04 v4.00.03.

Install

SlibBMP.lua -- Copy to somewhere in Lua's search path.

Color format of functions

bgcolor : BBBBB_GGGGGG_RRRRR (64K(16bpp) background color)

Internal bitmap data format

bitmap  = {}  
bitmap.header -- copyed from BMP header  
bitmap.width  -- bitmap width  
bitmap.height -- bitmap height  
bitmap.bit    -- bpp, 24 or 16(BBBBB_GGGGGG_RRRRR format)  
bitmap.flat   -- 1:Flat(Stuffing without leaving spaces for small image), 0:Stored in an array for each line.  
bitmap.data   -- bitmap data  

Usage

command	description
bitmap,mes = BMP:loadFile(path, flat)	Read content from file and return as bitmap bitmap: bitmap table mes: error message, if bitmap is nil path: path+filename flat: 1:data flat mode, 0:data array mode
res = BMP:saveFile(path, bitmap)	Dump bitmap to file res: "OK" or error message path: path+filename bitmap: bitmap table
img,mes = BMP:conv64K(bitmap or path)	Convert 24bit bitmap to 16 bpp bitmap If given path, read content from file. img: 64K color bitmap table mes: error message, if bitmap is nil bitmap: bitmap table path: path+filename
img,mes = BMP:conv64K(bitmap or path, x, y, width, height, bgcolor)	Crop out the 24bpp bitmap and convert it to 16bpp bitmap And replace the area out of the original image with the background color. If given path, read content from file. img: 64K color bitmap table mes: error message, if bitmap is nil bitmap: bitmap table path: path+filename

Licence

MIT

Author

GitHub/AoiSaya
Twitter ID @La_zlo