Difference between revisions of "En:Epimgconv"

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(further changes in 20 10 2008 version (2 colour mode not black-and-white, -outfmt parameter))
(New version 29 10 2008)
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=Version history=
 
=Version history=
24 10 2008: Datas are stored by type, not by field; automatically compressed .com files already run under EP64 as well; the header contains also the number of frames.
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'''29 10 2008''': Handling compressed format, mode/bias/palette and attr/pixel datas are stored separately (actually both of them are compressed). Thanks to the ordering of the palette and attributes, compression efficiency also got somewhat better.
  
 +
The downloadable package also contains the actual version of IVIEW.
  
20 10 2008:
+
 
 +
'''24 10 2008''': Datas are stored by type, not by field; automatically compressed .com files already run under EP64 as well; the header contains also the number of frames.
 +
 
 +
 
 +
'''20 10 2008''':
  
 
Setting VRES bit.
 
Setting VRES bit.
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19 10 2008: Pictures of any sizes between 1x1 and 8192x8192 are accepted; the internal compressor became faster and has somewhat better efficiency; Programs run also with EP64 (automatically compressed ones not yet). New parameters: -nointerp and -nocompress.  
+
'''19 10 2008''': Pictures of any sizes between 1x1 and 8192x8192 are accepted; the internal compressor became faster and has somewhat better efficiency; Programs run also with EP64 (automatically compressed ones not yet). New parameters: -nointerp and -nocompress.  
  
  
07 06 2008: -color0-7, -bias parameters also can be given; if the .com file is >48K, it'll be compressed.
+
'''07 06 2008''': -color0-7, -bias parameters also can be given; if the .com file is >48K, it'll be compressed.
  
  
02 06 2008: Attribute and interlace mode options.
+
'''02 06 2008''': Attribute and interlace mode options.
  
  
31 05 2008: First version, no attribute and interlace modes, only the black-and-white mode was with interlace.
+
'''31 05 2008''': First version, no attribute and interlace modes, only the black-and-white mode was with interlace.
  
  

Revision as of 11:49, 29 October 2008

The PC -> EP image converter program can be downloaded here. After unpacking (e.g with WinZip) it can be used in DOS prompt.

Using Epimgconv

An example for using it:

epimgconv foo.jpg foo.com

JPG, BMP, PNG, GIF and XPM input file formats are supported.

Parameters

Video mode can be chosen by -mode parameter, using the next values:

   * 0: 2 colours, normal vertical resolution (not surely black and white but an optimized palette is generated for each lines)
   * 1: 4 colours, normal vertical resolution
   * 2: 16 colours; a picture dithered to 256 colours is being converted into a picture of 16 colours without dither (default setting), normal vertical resolution
   * 3: 16 colours; it generates the same palette as mode 2 but the original picture is being dithered to 16 colours, normal vertical resolution
   * 4: 16 colours; it tries to mix generating palette and dithering but it's very slow, normal vertical resolution
   * 5: 256 colours, normal vertical resolution
   * 6: attribute mode, normal vertical resolution
   * 10: 2 colours (black and white), interlace (not surely black and white)
   * 11: 4 colours, interlace
   * 12: 16 colours; a picture dithered to 256 colours is being converted into a picture of 16 colours without dither, interlace
   * 13: 16 colours; it generates the same palette as mode 2 but the original picture is being dithered to 16 colours, interlace
   * 14: 16 colours; it tries to mix generating palette and dithering but it's very slow, interlace
   * 15: 256 colours, interlace
   * 16: attribute mode, interlace

So -mode 0-6 uses the normal vertical resolution and -mode 10-16 uses the interlace.


  • -raw 1 parameter enables to save in raw format (not usable without a separate viewer program), instead of the default .com application format; this way the size also can be larger (if the output format is application, size can be at maximum 46 characters * 288 lines only). -outfmt n also enables to save in raw format but with some compression at the same time - compression level must be given between 11 and 19.
  • -size W H enables to set picture size. W = Width in characters, H = Height in lines (interlace: field lines).
  • As default, Epimgconv converts images into the largest possible size, but by using -scale X Y and -offset X Y parameters the image can be enlarged and offset.
  • -color0 n ... -color7 m parameters can set fix palette colours (actually setting of avoiding using certain colours is not available). As -mode -0 and -mode 10 parameters don't result a black-and-white picture, -color0 0 -color1 255 parameters are needed to be given to reach black-and-white pictures.
  • -bias parameter sets fixbias - maybe better quality is available than by automatically selected colours. The colours can be given in #RGB format as well, e.g. #773 is white or #331 means bias=31.
  • If the .com file is too large (>48K), it'll be automatically compressed; so EXOS (being lucky) can load it though it starts much slowlier. Using -nocompress 1 parameter, automatic compression of "large" programs (>47.75K) can be turned off.
  • Parameter -nointerp 1 turns off interpolation while resizing a picture (e.g. converting from 32x32 to 512x512 2 colour interlace format without interpolation - this way all the pixels became a square of size 16x16.)


IstvanV

Suggestions, tips

I used the following methods and combined them:

  • attribute mode results the best quality and then the 4 colour mode;
  • I picked pictures containing not too complex structures;
  • I cut the better part from the picture but in the way that its composition remain pretty;
  • I looked for pictures where it's useful that there are lots of colours in the horizontally separated parts;
  • I picked pictures of strong colours and of many, diverse colours.

The better conversions were where these factors turned up the best way.


Endi

Version history

29 10 2008: Handling compressed format, mode/bias/palette and attr/pixel datas are stored separately (actually both of them are compressed). Thanks to the ordering of the palette and attributes, compression efficiency also got somewhat better.

The downloadable package also contains the actual version of IVIEW.


24 10 2008: Datas are stored by type, not by field; automatically compressed .com files already run under EP64 as well; the header contains also the number of frames.


20 10 2008:

Setting VRES bit.

2 colour mode doesn't use a definite black-and-white palette any more as default but an optimized palette is selected in each lines, like in the 4 colour mode. The former black-and-white mode can be set by using -color0 0 -color1 255 parameters;

New parameter: -outfmt.


19 10 2008: Pictures of any sizes between 1x1 and 8192x8192 are accepted; the internal compressor became faster and has somewhat better efficiency; Programs run also with EP64 (automatically compressed ones not yet). New parameters: -nointerp and -nocompress.


07 06 2008: -color0-7, -bias parameters also can be given; if the .com file is >48K, it'll be compressed.


02 06 2008: Attribute and interlace mode options.


31 05 2008: First version, no attribute and interlace modes, only the black-and-white mode was with interlace.