How to Add a New Field in Existing Kanban View in Odoo 17
Working With Photographs on Your Laser in CorelDraw
2. Objectives
What makes a good material
Diffusion patterns versus line screening
(gray scaling)
What makes a good photo
Initial Prep on the Photo – what makes a
good photo
Contrast Enhancement
Sharpening the secret to success
CorelDraw vsPhotoGRAVvs 1 Touch
Invert
Vignette
Cutout Lab in PhotoPaint
3. 6 rules of lasering photo
Always work in Gray scale (a continuous tone
image) or Black and white this depends on the
material you are going to laser on
Know your materials that you want to work on
Make sure that you know your speeds and
powers
Work only with good photos which shows only
the focus no background images
Know your adjustment commands
Crop to Focus
5. When we look at materials there are
three characteristics that we need to
consider
6. 1 The first is how well does the material that we
are working with hold a small well formed laser
dot
2 Secondly how well does that material display
our image. In other word do we see good
contrast. Is there a good difference in colour
between the colour of the lasered and non
lasered area. For example the best contrast is
black and white.
3 The third is how good is the material in terms of
being consistent. Wood is not good because it
has a changing grain, anodized aluminum is
very good because it has no grain
7. Products that hold a dot well are anodized
aluminum, laserable plastic or brass plated steel
10. Product such as wood do not hold a good small dot
and are very porous. Thus photos do not look as good
on this medium
11. Product such as glass do not hold a good small dot and are
very porous. Thus photos so not look as good on this
medium
12. What this means is that
when we process a photo
we need to establish first
what type of material that
we are going to laser on.
Once we have our material
we can process the image
14. Before we go on let us look at the 3 main
special programs for photo processing
ULS – One Touch
PhotoGrav
PhotoLaser
20. Our Number 1 Rule
Thus materials that hold a good small dot
need to be processed one way while those
materials that do not hold a good dot need
to be processed a different way
Let us look at the two ways we can
process an image.
24. Half toning - Definition
Halftone is the reprographic technique that
simulates continuous tone imagery through the
use of dots, varying either in size, in shape or
in spacing. "Halftone" can also be used to
refer specifically to the image that is produced
by this process. Where continuous tone
imagery contains an infinite range of colors or
grays, the halftone process reduces visual
reproductions to a binary image that is printed
with only one color of ink. This binary
reproduction relies on a basic optical illusion
that these tiny halftone dots are blended into
smooth tones by the human eye.
28. Products that typically require
continuous tonal image – Fine
Materials
Anodized Aluminum
Black Brass Coated Steel
Laserable Plastic
Some Marbles
Laser It
29. Half Tones which the laser produces
are Better on Anodized Aluminum or
Brass Plated Steel
30. What is Error Diffusion?
There is a second set of dithering patterns and
these are created using what is called an error
diffusion algorithm. These use a technique of
diffusing quantization error to neighbouring
pixels. Ok let us not get to technical. All you
need to understand is that there are a number
of error diffusion techniques that are available.
Which one that you use is up to you. In
CorelDraw we have 3 error diffusion algorithm
patterns available to us. These are “Floyd-
Steinberg”, “Jarvis” and “Stucki”. Others are
“Burkes”, “Scolorq”, “Sierra”, “Atkinson” and
“Filter Lite”. Figure 2 and 3 shows some of the
more popular patterns that are available to
use.
52. Best Photos Formats to get
Tiff or BMP are the best as long as they
are not jpeg’s just saved as this format
Jpeg is the next best but remember
JPEG can comes in a lot of different
qualities
You may get a PDF but the original file
may contain bad quality images
58. Once we have converted the image to
grayscale we will now need to process it
to laser engrave it.
The Contrast Enhancement Dialogue
box allows us to increase the tonal
range of the photo that we are working
on
To do this open up the Contrast
Enhancement Dialogue Box
61. What is Tonal Range
When we talk about the tonal range of an image we
are referring to the range of tones between the
lightest and darkest areas of an image. For example,
an image with a wide tonal range will include both
dark and light areas (and a range of tones in
between). Whereas an image with a narrow tonal
range will cover a more restricted range for example
it could be predominantly composed of mid-tones.
Note: when we look at an image that is a grayscale
image we have an image that is comprised of gray
pixels that have a value of 0 to 255. Values that are 0
are solid black and values that are 255 are solid
white. Pixels with a number in between 0 and 255
are a shade of gray.
75. Finished Product
Engraved
Dark Medium Lightest
little adjustment medium adjustment Big Adjustment
76. If you are lasering on black brass or
black anodized aluminum you will
need to invert the image so that is is a
negative.
77. We have worked with photos that would
traditionally be laser engraved on good
material such as laser brass or anodized
aluminum. But what about wood, glass
and granite?
To engrave this material we use what is
called the error diffusion technique
79. To Successfully Laser Engrave
Porous or Course Material like
Wood and Glass we need to do
an extra adjustment to our
photo
We need use an error diffusion
pattern
90. Now the question as to how much I adjust is
dependent on what I am putting the image on.
If I am going onto metal or plastic I would do a
lighter adjustment as I can show more detail
on this material. If I am going onto wood I
would use a more drastic adjustment
91. So the rule of thumb is more detail in your
image if you are going to go on good material
such as laser brass. This is because I am
going to use the halftone image to print my
photo. Thus I use a smaller adjustment in the
contrast enhancement command
If I am going on a porous product such as
wood I need to get rid of detail. Thus I would
do larger adjustment in the contrast
enhancement command
92. Remember that the worse (the more
porous) the material that we are working
on the more that we have to remove
detail, Thus the better the material the
less detail that we need to remove in the
photo
94. This technique is used all the time in
printing colour photographs because
more photos are digital and they suffer
from some sort of fuzziness. The
Unsharp mask will sharpen up these
photos. I use this technique because it
not only does it sharpens up my image
but it gets rid of some of the detail that I
can not produce. Thus the more detail
that I can not produce the more I use the
Unsharp mask
98. Now if I was going to laser
engrave a fine material I would
now send it to the laser
machine.
If I am going to a porous
material I need to do one extra
step
99. For our porous material we need to convert to Black
and White and use our Error Diffusion command