I started with this image which has allot of grays in it.
I then opened the image in Corel Photo Paint and Resampled the DPI to 600 to minimize pixelization and saved it in a BMP format so there were no artifacts injected from the JPG format compression.
I opened in the PicEngrave Pro 5 image editor and resized it for a .004" Pixel Resolution (step over) and the size of the wood plank I will be engraving on. I will be using our M140 445nm 2W Laser Diode engraver that has a .005" burn line width. Since I will be engraving a 1Bit Dithered B & W map image, I want the laser burn lines to slightly overlap by .001". This is not recommended when engraving grayscale images which would need the burn lines lay down next to each other instead. The Pixel Resolution setting needs to be determined by your laser's burn line width, so this is just a reference based on our 2W laser.
I adjusted the Gamma to .5 and set the contrast to 1.6 so it will lighten the grays and darken the blacks. I then Sharpened the image to 20 so it will bring out more detail. I then saved it again in the same BMP format for the reason I mentioned above.
I re-opened the edited/saved image for the Dithering process. I selected the Atkinson Algorithm and set the Error Constant to 150. Dithering the image ensures there is only pure Black & White in the image so the laser will only pulse on/off. This is what the image looked like after Dithering it.
Since this laser engraving will be done on our Mach3 machine using the J-Tech Photonics PicConvert board for the laser modulation, here are the PicEngrave Pro 5 settings I used to generate the gcode.
Here is where the PicConvert board can be purchased from: https://jtechphotonics.com/?product=dacpwm-converter-board
Here are the PicEngrave Pro 5 settings for when using the GRBL Firmware and streaming the gcode to your laser engraving machine with PicSender.
The same Pixel Resolution setting when editing the image must be used to ensure it laser engraves the desired size. With the Feedrate setting at 75IPM and Feed Rate Change at 20%, the laser will travel at 75IPM in White no burn areas and slow to 60IPM for burning the Black areas. The feedrate must be set based on your Laser's Wattage & burning power and the Feed Rate Change percentage based on the ability of your machine to accel/de-accel quickly through the abrupt feedrate change moves.
Here are the results on Poplar:
Noticed how crisp/sharp the text is and how detailed the overall map laser engraving came out.
When testing the Demo with TTL (laser Pulsing On/Off) B&W laser engraving, do not expect these kind of results because the Watermarks will add grayscale back into the image & cause the laser power to ramp up and down in the Black areas instead which will reduce the overall sharpness & detail. There are different image editing process for laser engraving grayscale for quality/detailed results.
For those testing our Demo programs that have very little experience/knowledge in the laser diode engraving processes and need professional advise/assistance, use our Contact & Links Page here:
https://www.picengrave.com/Contact.htm
https://www.picengrave.com/PicEngraver_Pro_5_+_Laser.htm