nrf_gfx_bmp565_draw

Hi,

I would display a picture on my lcd screen. I use the driver st7735, with PCA10040 and my IDE is segger embedded. I find the documentation of nrf_gfx_bmp565_draw

ret_code_t nrf_gfx_bmp565_draw ( nrf_lcd_t const *  p_instance,
nrf_gfx_rect_t const *  p_rect,
uint16_t const *  img_buf 
)

I don't find example with it.

I don't understand the last parameter: [in]img_buf Pointer to data from the .bmp file, because I don't know how can I have a pointer to data. 

In my code, I opened a picture with fopen, and I read this file with fread. I thought img_buf  was the result of fread, but no, it doesn't work or it displays anything. Here is my code

char * img_file ="../../../../../../couleurs.bmp";
char buff_img[100];
uint16_t img_size;
FILE * img = fopen(img_file, "r");
img_size = fread(buff_img, sizeof(buff_img), 1, img);
APP_ERROR_CHECK(nrf_gfx_bmp565_draw(p_lcd, &rect_img, img_size));

So i would like to have more information about nrf_gfx_bmp565_draw to understand how to use it.

Thanks!