How to create .bmp file from a rgb565 file

[shabeervsm]

Hai friends,
i wrote a usb camera driver program,using this program i transfer data from camera to my pc.But the camera output is rgb565 format data. How can i open this file in linux or how can i create a .bmp file from rgb. Anyone have idea about this or any good links ,pls help me asap......

regards shabeer

[WuNMOjTIQanXWBcH]

Preliminary explanation:
«rgb565» is the name of a BMP colour-bitmask¹ and simply states, that the colour bits of each pixel are consequetively saved in 5, 6 and 5 bits. Thus an «rgb565»-“file” actually already is a bitmap file. If the file additionally contains a DIB/BMP header, then it already is a BMP-file.

Answer:
Due to your inability to open the file[s] in question, it seems it/they do[es] not possess that/these header[s]. The solution is simple:

1. Use a program that can already do it, like i.e. ffmpeg².
2. Add a BMP header for 16-bit BMP files.
3. Convert it to another raw bitmap format (like rgb888, which means: 8 bits for each red, blue and green) and then add a valid BMP header. This approach was taken here. While I cannot vow for whether the code actually compiles (or for that matter: can be interpreted) or not, the algorithm is the core of the «rgb565 raw bitmap file» → «24 bit BMP file» conversion process (in this piece of code the BMP file header creation and the DIB scanline padding is abstracted in the “image” class instance). Adding a valid 24 bit BMP header is trivial, as it has only 2 variables, the x- und y-resolution:
   

   int scan_line_bytes = (4 - ((x_res * 3) % 4)) % 4;
   int payload_size = x_res * y_res * 3 + y_res * scan_line_bytes;
   bitmap_header_type bmp_header = {
   	.bfType = 19778,
   	.bfSize = payload_size + 54,
   	.bfReserved1 = 0,
   	.bfReserved2 = 0,
   	.bfOffBits = 54,
   	.biSize = 40,
   	.biWidth = x_res,
   	.biHeight = y_res,
   	.biPlanes = 1,
   	.biBitCount = 24,
   	.biCompression = BI_RGB,
   	.biSizeImage = payload_size,
   	.biXPelsPerMeter = 0,
   	.biYPelsPerMeter = 0,
   	.biClrUsed = 0,
   	.biClrImportant = 0
   };

   I donʼt know if ImageMagick can do this automatically for you. I tried (as stated in ³)
   

   $> ls
   RAWBMP_104x208.rawrgb
   $> convert -size 104x208 rgb:RAWBMP_104x208.rawrgb real.bmp;

   but this always aborted with the error message
   

   $> convert -size 104x208 rgb:RAWBMP_104x208.rawrgb real.bmp;
   convert: Unexpected end-of-file `RAWBMP_104x208.rawrgb': No such file or directory.

   Although this process always created the file “real.bmp”, the result never matched the input except for the filesʼ resolution (hints as to what I missed or what mistake I made are welcome).

Footnotes:

1. Microsoft Windows Bitmap: Summary from the Encyclopedia of Graphics File Formats – BMP Version 3 (Microsoft Windows NT)
2. RGB565 To PNG/JPEG | Software View
3. Hints and tips specific to Imagemagick:
   „[…] Convert RAW back to some other
   

   formatconvert -size widthxheight rgb:new.raw new.png

   […]“

[shabeervsm]

thankU for ur replay......