Arduino Mega 2560 Nokia 5110 LCD- Bitmap logo image is not seen as expected

Other Hardware Displays
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Hi friends! I am able to run prepared code from this web page: https://lastminuteengineers.com/nokia-5110-lcd-arduino-tutorial/ it works as expected (Marilyn Monroe seems as expected, as an logo).I am able to run pcdtest.ino example code also.But when I use my own image with some processes, it does not work as expected. Some meaningless dots appeared as scattered on pixels.It does not make sense.
I want to take a photo to use as an logo on my Nokia 5110 LCD.The LCD has 84*48 pixel resolution.Firstly, I took a photo.Resize it with Paint (width=84, height=48), and save it as monochrome bmp image.Then I save it as jpeg again to make it black and white(not grayscale). My PC has windows os. I tried image2cpp, LCDAsisstant, Rinky-Dink Electronics but only Convert picture to C code array works on my LCD (it works sometimes - image background color affects the result logo ).
I have trouble with this and dont understand the reason why these steps are not useful in my case.Can you help me with this?

#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_PCD8544.h>

// Declare LCD object for software SPI
// Adafruit_PCD8544(CLK,DIN,D/C,CE,RST);
Adafruit_PCD8544 display = Adafruit_PCD8544(7, 6, 5, 4, 3);

const byte einstein[] PROGMEM = {   
//This part is filled with bitmap .c file result 

};

void setup()   {
  Serial.begin(9600);

  display.begin();

  display.clearDisplay();

  display.drawBitmap(0, 0, einstein, 84,48, BLACK);
 
  display.display();

}

void loop() {}
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To post an image, you need to upload it to either your post as an attachment, or some other website where it is publicly available, then insert the link to that image file into the posting. :grinning:

The file on your own PC is not publicly available! :astonished:

Check out the instructions for posting.

4

Please post the original image from which you want to create a monochrome bitmap.
Since it is probably a public JPEG that you found on the Internet you can probably just post a link to it.

Converting to monochrome is a bit fiddly.
IrfanView on the PC can scale the image, convert to grayscale, then to monochrome dependent on a specific gray level.
It needs human judgement to choose the "best" image.
The final monochrome JPEG can be saved as a C array with an online program.

David.