Problems displaying BMP images using DFRobot_GDL library.

Hi Everyone. 

I am trying to load a bmp image to my screen (3.5” IPS capacitive Touchscreen Display) using the following line of code with no success. 

decoder.drawPicture(/*filename=*/"test_image.bmp",/*sx=*/0,/*sy=*/0,/*ex=*/screen.width(),/*ey=*/screen.height(),/*screenDrawPixel=*/screenDrawPixel);

This code has come directly from drawSDPicture example in the DFRobot_GDL library. The line of code works just fine when I use any sample image from Adafruit Imagereader Library but when I make my own bmp or get one online it wont write the image. I have no Compile errors and the code loads fine to my Uno. 

I have tried a bunch of different ways to save the test image as a bmp ( using paint and online converters), including rescaling the image to be smaller/larger with no change. 

Any help would be greatly appreciated. Thanks everyone.