Exchange of experience - Image conversion: Programs, tips, instructions.

                             
Exchange of experience              
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 Image conversion.           
 Programs, tips, instructions.     
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 (C) Konstantin Dvornik (lamurik)   
 and Denis Tokarczuk (additions)     
                                        
 Conversion - how much there is in this word...
This is roughly how one can characterize this
a topic that has been repeatedly raised in spec-
Trump's press. Still at dawnSpec-
room, we marveled in amazement at the excellent
the latest graphics in UFO, opened their mouths at
splash pictures and intro  ZX-
Formatfainted from grace
some conversions to Double Xinox'e and
X-Reversy... The latter is especially pleasing
la, since there were no conversions there-
anything, but tricolor ones are really real
absolutely brilliant invention of the Russian Federation
vein spektrumistov.  So we decided
contribute yours, perhaps a little late-
my full contribution to this inexhaustible topic...  
                                        
 - - -                  
                                        
 Naturally, the cash cow
teenager was chosen RS, as the most accessible
local and close (in the territorial sense)
le:)) car. But, as is known, there are different
different screen presentation formats, on
RS there are a huge number and,
Of course, the question becomes - which one?
choose format for conversion?  Most
suitable (convertible) are JPG,
VMR, RSKH.  For PCX on Spectrumessential
There are a lot of converters out there. The most successful
ny, in our opinion, is a converter
BRUJERIA, annexed to
the eleventh issue of Adventurer.  B
this converter has both a good interface and
work directly with MS-DOS floppy disks, and
support for extended memory, SETUP,
in which you can configure everything you want
Yes, conversion to chunk. However, applicable
it is, perhaps, only for the conversion of black-
white screens, although it provides the opportunity
ability to watch tricolor screens, but
The quality is, to put it mildly, not brilliant.   
                                        
And let's focus on b/w-pictures in
more details  Here another one arises, not
a less pressing question: than (what pro-
gram editor) convert the
whatever 1bM picture in one-bit
new format (b/w) with minimal loss
quality?  We recommend choosing for this
procedures not loved by everyone Adobe Photo-
shop (in this regard, its capabilities are all
are scarce), andCorel Photo Paint,in which
rum can be used in a convenient visualization mode
convert the image directly
butwatching the conversion result in the window
("before and after"). In addition, the program
offers several conversion algorithms
this ("threshold" (linear art), "on-
means", "Jarvis", "Stucky", "Floyd-
Steinberg", "Halftone", "Cardien-
ity-spread"),which are also
are regulated by some parameters.
It is by “sorting out” the algorithms and their para-
meters, you can achieve maximum quality
tbehhoro final conversion result
(after all, we see the result that
will be later on Spectrum).      
                                        
 However, we do not recommend making
version immediately from 16M into one-bit form
mat. First you need to “reduce” the picture
hky or “cut out” from it the part that
which is necessary for conversion. After
how the screen acquired the necessary size
size, convert it toB/W format (from-
tehku gray) and adjust its brightness -
contrast-intensity to this
moment when the white color becomes brighter and
"dark" places will be darker (naturally)
but we don’t get carried away and pay attentionattention
on the “legibility” of the picture).  And only
after that we convert into one
nobit format, as stated above. 
                                        
 All this would not be complete if we
did not provide examples of conversions by different me-
todami:                                 
                                        
 1. "Jarvis" algorithm,
 adjustable with one pa-
 pametpom ("bright depth
 bones").  At least the conversion
 this and does not shine with high
 quality, but the face is
 faceless scientist after all
distinguished through chaos
 dots.  The algorithm is often
 is the best when
 hbeptupobahuu details
drawn drawings.     
2. Algorithm "Cardien- 
ity-distribution". 
Also adjustable - 
with this parameter.    Not 
I know, maybe this me- 
then it turns out that - 
useful for kohbeptupo- 
any "large- 
ny" objects, but experience 
shows that this 
the least effective method is 
veins   
 3. Algorithm "Threshold" (cha-
 one hundred occurs called
 "Linear"). S Ein-
 the matte turned out to be the best
 shim, since facial features
 are clearly visible. One-
 however, the method is based only
 on cutting off one of
 brightness thresholds. Trace-

 possible "transitions" are
 blowouts are roughly cropped...  
4. Algorithm "Assigned". 
One of the most popular - 
new and, probably, simple- 
conversion algorithms 
this, since it was moved 
to Spectrum  and use 
zuetsya with kohbeptupo- 
in many conversions - 
printers.  Often appear- 
is the best converted - 
not detailed 
bathroom facilities.   
 5. "Halftone" algorithm.
 Same as Alg.2,hardly
 can it give a worthwhile
 conversion result
 exactly in Spectrum
 screens.  It's possible that
 when converting some
 large, non-detailed
 bathroom objects can
 be useful, but in
 never in our practice
 has not yet been applied.     
6. Stacky algorithm.
Very, very similar to 
first alg.1 ("Jar- 
vis"), however, 
there are some differences, 
which are visible only from - 
by means of close 
point-to-point comparisons 
ku". However, such a similarity - 
why did it happen - 
then in the case only with 
Einstein.  
 7. Floyd-Stay algorithm
 nberg". As well as  alg.1,6
 is effective for converting
 these detailed
 pictures.  Very effective
 tubeh during conversion
 photographs and small
 objects. The best
 This way saves
 smooth transitions brightc-

 puts a lot of dots.
                                        
 And now you have converted the image.
How to save it? To save without
hesitation, we select the format .рсх, since
it is easy to view and convert -
Xia in Brujeria.  If we risk saving
picture in .bmp - Brujeria although
separates the format, but convert it separately
it seems (or rather, it will start, but it will show how
some nonsense).  If, however, you
saved screen to .bmp, then for this
format there are also many conversions
torov.  The most popular areVMR-
VIEW, VMR color by BROTHERS, VMR
service by BROTHERS.The first one has no
what bells and whistles, but maybe kohbeptupo-
create big pictures, but only
B/W.                                    
                                        
 Now let's focus on the conversion
color screens. They are also pre-
it is advisable to “prepare” on PC - that is
bring to the required size and
vary" colors (bright on this ek-
make the wound even brighter, dull
to make the most, so to speak, “unambiguous”
chny" - that is, some one color
ta). We prepared a picture, and in what fo-
should you save?  And here there are two options -
that - either .bmp,  or .jpg. Priority
seems to be the second format, because the converter
BMP color although it makes it possible to
convert  .bmp immediately to Y (tricolor
format) and view the result without
mediocre, here, but converts
only 256*192, 256-color BMR and absolute
but does not create textures, which is why the pictures
appear "square". There is another va-
Converter option .bmp format - BMP-ser-
vice.  The same thing, only converts to
normal screen.                          
                                        
 JPG format.  For him there is a
in my opinion, one converter - JPEG-VIEWER by
Alien Factory. But, believe me, it will be enough
to you in full! When loading you will see me-
nude, in which you can select the drive,
start the process, find out about the authors. He
supports both TR-DOS, andMS-DOS,
which is very cool. In the process start menu
you can set the brightness and contrast -
ness. They need to be configured accordingly
vii with the parameters of PHOTOSHOP. And if not
you know - look at the picture.  If
picturebig - there is a possibility ee
reduce or kohbeputb a separate part.
And the main trump card is that the converter
can highlight colors from a picture - R,G,B
respectively.  Ckohbeptupobab one of
flowers, save - he will supply the corresponding
Existing extension R, G and B. When dry
pahute all 3, get out of there.          
                                        
 Unfortunately, the converter is not supported
is #3D13.  So owners of HDD, and
RAM DISKs will have to be broken off. Like
to me, a happy user of RAMDISK.
So, you have saved all 3 colors. Now
glue them together. STS or something else
and at the very beginning you need to put RST#38:
is #3D13.  So owners of HDD, and
RAM DISKs will have to be broken off.Like
to me, a happy user of RAMDISK.
So, you have saved all 3 colors. Now
glue them together. STS or something else
and at the very beginning you need to put RST#38:
RST#38:RET RO. Otherwise, the viewer will determine
lit package. So, the operation on 3-COLOR'
omfinished. You can view3-COLOR
in X-COLOR or use in your game!
                                        
 Somehow summing up everything written above -
no.   The best converter of b/w-pictures -
Brujeria.  And the best converter of color
pictures - JPEG-VIEWER. And, accordingly,
but, formats: b/w - .рсх, color - .jpg.  
                                        
 P.S.  In the newspaper supplement you can
find hrip-archive with programs JPEG-VIE-
WER and X-COLOR, as well as some examples
converted tricolor images.