Mbed display image SD card on stm32f769i_discovery


I am trying to display an image using the SD port on my board (stm32f769i_discovery). I tried using the SDFileSystem (SDFileSystem - SDFileSystem | Mbed) by doing :
SDFileSystem sd(SPI_MOSI, SPI_MISO, SPI_SCK, SPI_CS, “sd”);
and after initialisation of the LCD
BSP_LCD_DrawBitmap(0,0,(uint8_t *)"/sd/minion480x272.bmp");

The program compiles, the LCD lights up but then the screen is completely messed up like an old TV crashed screen.

Could someone help me?

Thank you !!