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- _______________________________________________________________________________
-
- Translator 6.21 -------------------------------
- This program is PUBLIC DOMAIN
- Version date : 26 Aug 1990 -------------------------------
-
- ----------------
- - Introduction -
- ----------------
-
- Translator will translate image files from other computers to the Archimedes.
- The following image files are supported :
-
- - Atari PI1,PI2,PI3,PC1,PC2,PC3 files (320x200x16, 640x200x4 and 640x400x2,
- uncompressed and compressed)
- - Atari IMG files (monochrome only)
- - Amiga IFF files (including HAM and halfbright modes)
- - MacIntosh MacPaint files (576x720x2 b/w)
- - GIF (Graphics Interchange Format) files
- - Archimedes' sprite files
- - ProArtisan compressed (type 0 and 1) files (640x256x256)
- - Watford digitiser files (512x256x64 greys)
- - Render Bender files (256 colour mode images)
- - AIM files (256x256x256 greys)
- - SUN Microsystems files (1/8-bit per pixel uncompressed)
- - PCX files (2/4/16-colour EGA and 256-colour MCGA)
- - TIFF files (bilevel, greyscale, palette colour and RGB full colour (also
- known as TIFF Classes B,G,P and R), uncompressed or PackBits compressed,
- 1,2,4,8 or 24 bits per pixel)
- - QRT RAW (24-bit RGB) files (Quick Ray Tracer)
- - ArVis Videographics (15-bit RGB) files (2 sprite files in HIP/LOP dirs)
- - Translator's own 'Clear' files (pure 24-bits RGB and up to 8 bit per pixel
- with palette, any resolution, refer to 'Clear files' for more information)
- - MTV (Marc Terrence VanDeWettering) ray tracer images (24-bit RGB)
- - 'CadSoft' (used by Cadsoft and Millipede PRISMA digitiser) images (8 bit
- per pixel colour)
-
- -------------------------
- - Using the application -
- -------------------------
-
- To start up Translator, double-click on the '!Translatr' icon. It will
- install itself on the icon bar, and clicking MENU on Translator's icon will
- give the usual 'Info' and 'Quit' options. Clicking SELECT or ADJUST will
- pop up the options menu, but most options will not be selectable at this stage.
-
- Loading an image can be done in three ways :
- a) by dragging the image file to the Translator icon on the icon bar
- b) by dragging the image file to the image window (when an image is loaded)
- c) by double-clicking on an image file (not for 'native' Archimedes formats,
- to ensure that the originating programs (when loaded) 'catch' these files,
- not Translator)
-
- NOTE : The ArVis Videographics format consists of two sprite files per image,
- of which one resides in a directory named 'HIP', the other in a directory
- called 'LOP' (both at the same directory level). To load an ArVis image, drag
- the sprite file in the 'HIP' directory to Translator (i.e. a or b).
-
- Image files should be filetyped appropiately to be recognized by Translator.
- The following filetypes are used by Translator (the filetypes in the range
- &690-&6xx are new filetypes, used for foreign formats) :
-
- -------------------------------------------------------------------------
- Filetype Name Image file type/origin
- -------------------------------------------------------------------------
- &004 AIM AIM (Archimedes Image Manager)
- &690 *Clear Translator Clear
- &691 *Degas Atari PI1,PI2,PI3,PC1,PC2,PC3
- &692 *Img Atari IMG
- &693 !*AmigaIFF Amiga IFF (ILBM)
- &694 !*MacPaint MacIntosh MacPaint
- &695 !*GIF GIF (Graphics Interchange Format)
- &696 !*SUN SUN Microsystems
- &697 *PCX PC PCX
- &698 *QRT QRT (Quick Ray Tracer) RAW
- &699 *MTV MTV ray tracer
- &69A !*CadSoft CadSoft/Millipede PRISMA
- &D58 RendPic Render Bender
- &DE2 ProArt ProArtisan
- &DFA Picture Watford digitiser
- &FF0 !*TIFF TIFF (Tag Image File Format)
- &FF9 Sprite Standard Archimedes sprite file (or ArVis, see above)
- -------------------------------------------------------------------------
- A '*' indicates which filetypes also load by method c) (see above).
- A '!' indicates which filetypes can be recognized and loaded without having
- the correct filetype. You can choose to give these files the correct filetype
- yourself, or leave them as they are.
-
- Every new filetype is represented in filer windows by its own icon, which
- is similar to Translator's iconbar icon.
-
- When succesfully processed, the image will appear in a resizable, scrollable
- window.
-
- --------------------
- - The options menu -
- --------------------
-
- Clicking MENU on the image window (when an image is loaded) or clicking
- SELECT or ADJUST on the iconbar icon will pop up the options menu :
-
-
- --------------
- | Image info |
- --------------
-
- This icon gives access to an information window, in which the resolution,
- compression technique, filename, etc. of the image is displayed.
-
-
- ----------
- | Pop up |
- ----------
-
- This icon gives access to a submenu in which options can be set that influence
- the way that the image first appears when succesfully processed :
-
- 'Auto mode'
-
- Clicking this icon will toggle the 'auto mode' flag. When it is ON (i.e.
- ticked) Translator will select the most suitable mode for display of the image
- for you when the image appears in its window. When OFF, you can/must choose
- the mode yourself (possibly using the image information provided under 'Image
- info').
-
- 'Auto palette'
-
- Clicking this icon will toggle the 'auto palette' flag. When it is ON (i.e.
- ticked) Translator will select the 'Image palette' (see below) automatically
- when the image appears in its window. When OFF, the palette remains unchanged.
-
- 'Auto zoom'
-
- Clicking this icon will toggle the 'Auto zoom' flag. When it is ON, then
- Translator will attempt to zoom out (never in though) on the image so that it
- fits entirely on the current mode's screen.
-
- 'View mode'
-
- Clicking this icon will toggle the 'View mode' flag. When it is ON, then
- when a new image is loaded, the current mode is remembered, and is re-selected
- when the image window is closed.
-
- 'Mode set'
-
- This icon gives access to a submenu of 'mode sets'. When one of these
- mode sets is 'active' (default is none), selection of the mode for
- display of the image will be via this mode set. Each mode set consists
- of four mode numbers, for 2,4,16 and 256 colour display requirements
- of the image respectively. There are two standard sets : 'Normal' (modes
- 0,8,12 and 15, all 640x256 pixels) is for users of all monitors, 'Multisync'
- (modes 18,19,20 and 21, all 640x512 pixels) is for users of multisync
- monitors only. A third set is user-definable and must contain the four
- required mode numbers seperated by comma's (for 2,4,16 and 256 colours
- respectively). Selecting 'None' in this submenu will switch off the mode
- set option (so the 'closest' mode will always be selected, as normal).
-
-
- --------------
- | Processing |
- --------------
-
- This icon gives access to a submenu in which options can be set that influence
- the way in which the image is processed :
-
- 'Clear output'
-
- When this icon is ticked, a 'Clear' file will be created from the next image
- loaded into Translator. This icon gives access to a file window, in which a
- Clear file may be 'opened' by dragging the filetype icon to a filer window.
- By clicking on this icon, Clear output is cancelled and the last opened Clear
- file (which is always empty at this stage) is deleted.
- Refer to 'Clear files' for more information.
-
- 'Output mode'
-
- The output mode for the image may be freely chosen. This icon gives access
- to a submenu, in which two choices of output mode may be selected :
-
- - Auto
-
- When this icon is selected (i.e. ticked), Translator will determine the
- best possible output mode (and palette) to display the image. For example,
- for pure RGB and 256 colour images, a 256 colour mode (with at least the
- required resolution) will be chosen for output, whereas if the image has
- 5-16 colours, or 3-4, or 1-2, a 16, 4 or 2 colour mode respectively.
- The 'Auto' setting is the default setting, as you will usually want the
- highest image quality.
- The palette is not changed in 256 colour modes (i.e. the standard palette
- is used, a 'principle' that can be found in more places throughout
- Translator), while in other modes the image's 'exact' palette is used
- for optimal results.
-
- - Current
-
- When this icon is selected (i.e. ticked), the current mode will always
- be used as the output mode, and thus also determines the number of colours
- in the resulting Archimedes image. This may be useful when the quality
- of the image is not of the utmost importance, but other considerations
- play a major role. For example, if you wish to create a desktop icon based
- on some image, or you want the resulting image to be usable by Artisan (which
- can only work in 16 colour modes, in contrast to Pro-Artisan), you may
- specifically select a 16-colour mode for output.
- When this icon is ticked, the 'Output palette' icon also gives you control
- over the output palette (see its discussion below).
- 'Error spreading' (see below) will help to still reach a result as close as
- possible to the original, given the limited number of colours and non-ideal
- palettes that may be chosen.
-
- 'Output palette'
-
- This icon gives access to a submenu in which a choice for the output palette
- may be made. NOTE : This is only effective when 'Current' is selected in
- the 'Output mode' submenu, as when 'Auto' is selected, Translator determines
- the best possible output palette.
-
- - Current
-
- When this icon is selected (i.e. ticked), the current palette is used for
- the output image. Usually this is the desktop palette (ideal for creating
- icons), but via either palette file loading or palette manipulation by hand
- (via the palette utility), any palette may be chosen. In 256 colour modes
- however, the output palette used is ALWAYS the standard palette.
- There are some example palette files for 16 colour modes in the 'Palette16'
- directory. These contain palettes that divide the 4 available colourbits
- between red, green and blue (i.e. 2,1,1 or 1,2,1 or 1,1,2 respectively),
- and one palette with 1 bit red, blue, green and 'tint' (amount of white).
-
- - Default
-
- When this icon is selected (i.e. ticked), the current mode's default palette
- is used (as following a VDU20). In 16 colour modes, the upper eight 'flashing'
- colours are not used.
-
- - Greyscale
-
- When this icon is selected (i.e. ticked), a greyscale from black up to
- full white will be used. This may be especially useful for black and white
- images.
-
- 'Scaling'
-
- This icon gives access to a submenu with a further submenu leading to the 'x'
- (width) and 'y' (height) scaling factors.
-
- The scaling factors may be entered as 'multiplier:divisor' or 'multiplier'.
- The difference is, that the former defines an 'absolute' scaling, and that
- the latter (the 'simple' form) defines exactly the number of pixels you want.
- When using the 'simple' form, for example the X scaling ratio will (re-)appear
- as e.g. '100:x' when you entered '100'. This is to make clear that the exact
- scaling ratio is dependant upon the number of (x and/or y) pixels in the input
- image(s) that will be loaded subsequently.
-
- You can define any scaling ratio you want (i.e. you can scale the image both
- up or down). The ratio is automatically divided down to the lowest form,
- so you may enter any ratio that seems convenient. For example, to scale down
- a, say, 640x512 pixel image to 600x480 pixels, you would enter '600:640' (or
- simply '600') and '480:512' (or simply '480') for 'x' and 'y' respectively.
-
- Using the 'simple' form, it is possible to scale all subsequently loaded
- images (down or up) to an image with a fixed resolution. The 'absolute' form
- enables a fixed scaling to be defined for all subsequently loaded images.
-
- When scaling is active (i.e. not 1:1), the 'Scaling' icon will be ticked.
- Clicking on the '1:1' icon will reset the scaling factors to normal (both x
- and y 1:1), while clicking on any of the remaining icons will select a preset
- scaling for both x and y (i.e. 1:2, 2:1, etc.).
-
- When scaling without error spreading being active, obviously pixels are simply
- discarded (when scaling down) or duplicated (when scaling up). Usually, in
- this case, you can do the scaling equally well by using the scaling options of
- the save functions (which do exactly the same).
- However, when error spreading is active, you are likely to get a much better
- quality if you pre-scale the image (by setting the appropiate scaling factors
- here) and THEN save it (in full). This is because, after error spreading,
- every pixel's 'neighbor(s)' usually contains a correction for the pixel's
- true colour. When scaling down/up with the 'Save' or 'Zoom' options, you just
- lose or duplicate these 'neighbor' pixels and the error spreading effect may
- be either completely lost (when scaling down, because the corrections in
- the discarded pixels are lost) or not optimal (when scaling up, because all
- the duplicated pixels could have been used to more finely spread errors).
-
- 'Error spreading'
-
- This icon gives access to a submenu, in which Translator can be set to use
- one of two kinds of error spreading, or none. The icon is 'ticked' if error
- spreading is enabled.
- When either error spreading is on (i.e. ticked), errors made by the
- approximation of the input pixels' RGB valus in all output modes are spread
- out (locally) over the image. This usually results in images with a much higher
- quality, so you will usually leave error spreading on.
- When you switch it off only the best approximations to colours are used, and
- the errors made will be completely ignored. You may want to do this to compare
- results. When there are enough colours and the ideal palette can be selected,
- i.e. always in non-256 colour modes when 'Auto' mode is on (see above), error
- spreading will have no effect, as there will be no errors.
- There are two choices of error spreading available, which differ in the way
- they spread the approximation errors :
-
- - 'Simple'
- This spreads out the errors along the same pixel row only. In fact, it gives
- one of its neighbor pixels the full error factor, as follows :
-
- ------------------------------------------
- | | Current pixel | full error |
- ------------------------------------------
-
- This is the fastest of the two, and gives very good results.
-
- - 'Floyd Steinberg'
- Floyd Steinberg error spreading, devised by R.W. Floyd and L. Steinberg,
- spreads the errors made more intelligently. It divides the error factors
- among four neighbor pixels (instead of one), as follows :
-
- -------------------------------------------------
- | | Current pixel | 7/16 of error | <-- current line
- -------------------------------------------------
- | 3/16 of error | 5/16 of error | 1/16 of error | <-- next line
- -------------------------------------------------
-
- The results are usually better than when using 'Simple' error spreading, but
- to which degree depends heavily on the type of image. Digitised images will
- usually benefit much less than 'drawn' images. The penalty is that it is
- computationally much more expensive than 'Simple' error spreading, so you'll
- have to wait a few seconds longer.
-
- 'Black and white'
-
- Clicking this icon toggles the 'black and white' flag. When it is ON (i.e.
- ticked), Translator translates colour images to grey images. In >16-colour
- images, this gives very good results when used in combination with error
- spreading. For images with 16 or less colours, only the palette is changed
- to the closest greys.
-
- 'Zig zag'
-
- Clicking this icon will toggle the 'zig zag' flag. When it is ON, and error
- spreading is also ON, every other line will be plotted in the opposite
- direction, i.e. left to right, then right to left, then left to right again,
- etc.. This reduces the chances of patterning effects in the final image.
- Sometimes, however, the effect is not so pleasing, so you may switch it off.
- When OFF, lines are always plotted left to right.
-
- 'RGB resolution'
-
- This icon gives access to a window in which the amount of red, green and blue
- in the resulting image can be defined. The slider values for red, green and
- blue represent the number of bits (0-8) of the corresponding primary colour
- that are 'let through' in the final image. You can drag the sliders to change
- the number of bits (a full bar is 8 bits).
- For example, red=8, green=0, blue=0 will give a red seperation of the input
- image, i.e. only the red components of the colours are let through. Depending
- on how many bits are reserved for each of the primary colours in each graphics
- format (mostly 8 bits giving 24-bit RGB, but sometimes 4 bits or less), a
- large range of effects and colour seperations can be achieved.
-
- 'Screen blanking'
-
- Clicking on this icon toggles the 'Screen blanking' flag. When it is ON (i.e.
- ticked), the screen will be blanked while unpacking an image. This may speed
- up the unpacking considerably when working in high resolution modes (with high
- video DMA overheads). When it is OFF (default), the screen will not be blanked
- while unpacking (so you'll have to wait a bit longer...).
-
- 'Invert RGB'
-
- Clicking on this icon toggles the 'Invert RGB' flag. When it is ON (i.e.
- ticked), the colours in the image will be processed 'inverted'. This results
- in 'negative' images for both colour and black and white images.
-
- 'GIF scan'
-
- Clicking on this icon toggles the 'GIF scan' flag. When it is ON (i.e. ticked),
- GIF files are scanned to count the number of pictures in them. This number will
- appear in the image information. When the GIF image contains more than one
- image (which is rare), you may select one by using the 'Image number' option
- (see below). When OFF, GIF files are NOT scanned, and are assumed to contain a
- single image (which is usually so). This has the advantage of substantially
- reducing the loading time. The image info will reflect the unknown number of
- images in the file by displaying a '?' instead of the image count.
-
- 'Image number'
-
- GIF image files may contain more than one image, and Archimedes sprite files
- may contain more than one sprite. When this is the case, the image info window
- will indicate this. By default the first image or sprite is displayed, but,
- by altering this writable icon to 'n', the n-th image or sprite will be
- chosen when the file is (re)loaded into Translator. When the nth image is
- not present, Translator will complain (except when dealing with GIF files and
- the 'GIF scan' flag is OFF).
-
- 'Percentage'
-
- Clicking on this icon toggles the 'Percentage' flag. When it is ON (i.e.
- ticked), the hourglass shows a percentage indicating the amount of rows
- that have been 'built' so far. It does not always indicate how much of the
- processing is done, for example, GIF first decompresses all the image data
- before building the rows.
-
-
- -----------------
- | Image Palette |
- -----------------
-
- Clicking on this icon selects the currently loaded image's own (or 'output')
- palette. It is selected by default when the 'Auto palette select' flag is
- on, after the image is loaded. Note that this MAY make things badly (or not
- at all!) visible (e.g. menu's, etc.). Re-selecting the image's palette may
- be necessary after using the desktop's palette utility (e.g. 'Default') or
- when some other application changes the palette.
-
-
- --------------
- | Zoom image |
- --------------
-
- This icon gives access to a submenu of zoom options :
-
- 'In', 'Out'
-
- These icons give access to zoom in and zoom out options respectively. Zooming
- takes place in steps of 2 (i.e. 2 times, 4 times, 8 times enlarged/reduced,
- etc.). By clicking one of the icons given in their submenu's, zooming can be
- performed in x ('x') or y ('y') directions individually, or both at the same
- time ('Both').
-
- '1:1'
-
- Clicking this icon will reset the zoom factors to 1 (i.e. the image is neither
- enlarged nor scaled down).
-
-
- -------------
- | Magnifier |
- -------------
-
- Clicking on this icon pops up the magnifier window. The magnifier window shows
- a (magnified) part of the image. By clicking either SELECT or ADJUST within
- the image window, the area around the point clicked on will appear in the
- magnifier window, with the point itself in the middle. You can shift through
- the image by holding the button down and moving the pointer.
- The magnifier window starts up at 1:1, and the magnification may be increased
- by clicking SELECT or decreased by clicking ADJUST, within the magnifier
- window. The MENU button will select 1:1 magnification.
- The magnifier enables you to examine image areas with ease.
-
-
- ----------------
- | Rotate image |
- ----------------
-
- This will rotate the image clockwise by 90 degrees. This may be convenient with
- high-and-narrow images (especially on normal monitors), so more of the image
- can be on-screen without you having to use the scroll bars.
-
-
- ----------------
- | Mirror image |
- ----------------
-
- This icon gives access to two mirror options. Clicking 'x' will mirror the
- image horizontally, while 'y' will mirror it vertically.
-
-
- -------------------
- | Include palette |
- -------------------
-
- Clicking this icon will toggle the 'include palette' flag. When it is ON (i.e.
- ticked) any saves will save the current palette with the sprite. When OFF, no
- palette is saved with the image.
-
-
- --------------
- | Save image |
- --------------
-
- This icon gives access to a submenu of five ways in which (part of) the
- image may be saved :
-
- 'Full'
-
- This will save the whole image as a single sprite, exactly as it is stored
- internally (i.e. without losing pixels). The sprite can then be used
- in full (e.g. dumped to a printer with suitable software), or scaled as
- required by another application (e.g. a DTP package). The palette saved
- (when the 'include palette' flag is ON) will always be the image's own
- palette (not the current one, as with the other 'saves').
- NOTE : In 256 colour modes, the palette will NOT be saved, regardless of
- the 'Include palette' flag, as Translator never changes the palette in
- these modes.
-
- 'Whole', 'Whole (scaled)', 'Part', 'Part (scaled)'
-
- These will display the image on the current mode's screen, using the
- currently selected palette, and save an editable part of the on-screen
- image to a sprite file.
- By selecting one of these four 'saves', you can choose whether or not you
- want to scale the image (the '(scaled)' saves will let you do this), and
- whether or not to cut out a specific piece (the 'Part' saves will let you
- do this, the 'Whole' saves won't), prior to saving.
- The palette saved (if the 'include palette' flag is ON) will be the
- current one, i.e. a la *SCREENSAVE. While scaling and/or cutting, the mouse
- pointer will continuously show the size of the scaled or cut-out image in
- pixels, or the pixel coordinates of the mouse pointer before clicking on
- the top left corner of a cut-out.
-
- Saving is done by dragging the sprite file icon (which appears before any
- scaling or cutting is done) to a directory viewer. Alternatively, you may
- save the image sprite directly into another application (e.g. !Paint), by
- dragging it to the application's iconbar icon or one of its windows.
-
-
- ----------
- | Status |
- ----------
-
- This icon gives access to a submenu of status handling functions. A default
- status can be created, which contains the Auto mode select, Auto palette
- select, Error spreading, Black and white, Auto zoom, View mode, Screen
- blanking, Invert RGB, GIF scan, Include palette and Zig zag flags and the
- Mode set.
-
- The 'Save' option will save the current status of the abovementioned items as
- the default. This default status file (when present) will be loaded on
- startup, or explicitly with the 'Load' option in the submenu (to override
- the current ones). The 'Kill' option will remove the default status file,
- so the 'standard' (Translator) defaults will be used on the next startup.
-
-
- -------------
- | Hourglass |
- -------------
-
- The hourglass is normally displayed when any processing is done. In addition,
- during image processing, the top 'LED' will be 'on' when data is being
- loaded from disc. It will be 'off' when processing is taking place. Also,
- when the 'Percentage' flag is on, during buildup of the image rows the
- percentage of rows done so far will show in the hourglass.
-
-
- ---------------
- | Clear files |
- ---------------
-
- Translator can output its own graphics file format, called 'Clear' (filetype
- &690). I devised this (simple to use) new filetype because of several
- shortcomings of Archimedes sprite files (which were the only output) :
-
- - Pure RGB input (Amiga IFF HAM, QRT, ArVis) at best ends up in a 256 colour
- sprite with standard palette on which error spreading has been applied.
- This loses a lot of image information.
- - 'Palette and pixel value' input (i.e. the rest of the formats) always lose
- any extra bits in their palette definitions if they use more than 4 per
- primary colour (which is the maximum on the Archimedes). In addition, output
- in 256 colour sprites will always lose palette definition because of the
- inability to fully define all 256 colours (and thus the error spreading
- makes the best out of the standard palette).
-
- Without being able to output a 'fully accurate' filetype, it would thus be
- impossible, in most cases, to retain the full resolution (both in terms of
- pixels and colour definition) of input images. This may be essential if
- the images that Translator can read are to be put to more serious use, for
- example image manipulation, or conversion to other formats (!MakeGIF and
- !MakeTIFF !).
-
- Also, I envisaged that it should be very easy to extract the image data from
- this 'fully accurate' format, so people can quickly and easily write simple
- programs to process it (i.e. no compression, no 'pixel value packing', etc.).
-
- The 'Clear' graphics format was devised because of all this, and holds either
- pure 24-bit RGB data or byte-wide pixel values with a 24-bit RGB palette (one
- entry per pixel value). The full format is as follows (the descriptions
- are necessarily 'formal' to avoid misinterpretation, the format is actually
- extremely simple) :
-
- Offset Bytes Description
- ----------------------------------------------------------------------------
- 0 m Maker (string, e.g. 'Translator')
- m 1 0 (string terminator)
- m+1 4 Version number (600 currently, i.e. 6.00)
- m+5 4 Width of image in pixels (w)
- m+9 4 Height of image in pixels (h)
- m+13 4 Bits per pixel (bpp)
- If 1<=bpp<=8, then 24-bit palette entries for all colours
- follow (i.e. n=3*2^bpp, and l (bytes per pixel) is 1).
- If bpp>8, then pure 24-bit RGB is stored, which needs no
- palette (i.e. n=0, and l (bytes per pixel) is 3)
- m+17 n Palette entries for all colours (only if 1<=bpp<=8), which
- are triples of byte values (0=off, up to 255=full intensity)
- per primary colour, red first, then green, then blue.
- For example, when 'Rx','Gx' and 'Bx' represent the intensities
- of red, green and blue respectively for colour x, the palette
- for 4 colours (bpp=2) would be stored :
- R0,G0,B0, R1,G1,B1, R2,G2,B2, R3,G3,B3.
- m+17+n w*h*l Pixel values, representing the image rows from top to bottom
- and every row from left to right.
- If l=1, every pixel value is a byte representing the colour
- number/index.
- If l=3 (pure 24-bit RGB), data is stored like the palette
- entries, i.e. red first, then green, finally blue, all
- byte values (0-255) representing the intensity of the
- corresponding primary colour for that pixel.
- ----------------------------------------------------------------------------
-
- In the case of pure 24-bit RGB storage (i.e. bpp>8), bpp represents the
- bits of RGB resolution of the original image (i.e. 12 for Amiga IFF HAM mode,
- 15 for ArVis and 24 for QRT currently). If there are less than 8 bits per
- primary colour, lower bits are set to 0 (but do not try to deduce how
- many per primary colour if you don't know what the original image was).
- For example, in the case ofáArVis' 15 bits RGB (5 bits each for red, green
- and blue), the lower three bits of each pixel value are set to 0 when
- Translator creates the Clear file.
-
- When 1<=bpp<=8, only the lower 2^bpp pixel values of the 256 available
- are used.
-
- Clear files are always 'pure' representations of the input images, i.e.
- error spreading, black and white conversions, etc. are NEVER applied,
- even if they are 'on'.
-
- Clear files DO obey the scaling factors you have set however, so that you
- may easily create Clear files of, for example, a specified number of pixels.
- For example, you may scale images to 256x256 pixel Clear files and then let a
- simple program (calculating greyvalues out of the pixels' RGB values) turn
- them into AIM files.
-
-
- -----------------------
- | Memory requirements |
- -----------------------
-
- Translator starts up taking a minimum amount of RAM. As and when images
- are loaded/discarded, extra memory is claimed/released, as follows :
-
- - When an image is loaded, all available memory is grabbed (to ensure maximum
- file buffer sizes), and an attempt is made to load the image. When there is
- too little memory available, Translator will complain. After loading (which
- may or may not be succesful), all memory that is not needed anymore (i.e. all
- but the internal image sprite) is returned to the system.
-
- - When an image is discarded, i.e. by closing the image window, the memory
- taken up by the internal image sprite is also released.
-
- This memory allocation strategy ensures that
-
- a) all available memory is used to speed up processing
- b) Translator runs in the minimum amount of memory needed
- c) you do not need to worry about how much memory to allocate to Translator
-
-
- ---------------------
- | Mode independance |
- ---------------------
-
- When the 'ideal' mode cannot be selected (usually because of screen memory
- shortage), a beep will sound and succesively lower resolution modes with the
- right number of colours are tried by Translator (as, within the WIMP
- environment, there is no telling how much memory can and will be allocated
- to the screen by the WIMP/desktop system).
-
- Once an image has been created, it can be displayed in any mode. In modes
- with the 'wrong' number of colours, Translator attempts to display the
- image as well as possible, as follows :
- - If the number of available colours is larger than the required number of
- colours for the image, the 'lower' part of the palette is set (<=16 colour
- modes) or (256 colour modes) the closest available standard colours are
- selected.
- - If there are too few colours (i.e. only in <=16 colour modes), the most
- frequently used colours (the 'base' colours) in the image will determine
- the palette, and the remaining colours will be mapped to the closest base
- colour. This gives acceptable results for most images (for 256-colour images
- in 16, 16 in 4, or 4 in 2 colour modes), up to perfect results for 256-colour
- grey images (for example with the black and white option on) in 16 colour
- modes (as it is only ever possible to display 16 different greyvalues, also
- in 256 colour modes).
-
- Of course, if you really want a non-ideal mode to save your image in,
- selecting it as the output mode in the first place (see 'Output mode'
- and 'Output palette') gives much better results !
-
-
- ----------------
- | Sprite files |
- ----------------
-
- Archimedes sprites may not have a palette. If they don't, the standard
- palette settings in the sprite's mode is used. The palette of 256-colour
- sprites is always ignored (the standard one is always used). Also, if the
- mode contained in the sprite is a valid one (i.e. it is a valid WIMP mode
- and it is available on your monitor), then this is used by default. If
- the mode is not valid, then the 'closest' mode is determined and used as
- usual.
-
-
- -----------
- | The end |
- -----------
-
- If you have praise, complaints, comments, bugs(!) or information about other
- formats to offer me, do not hesitate to write to
-
- John Kortink
- Middelhuisstr. 17
- 7482 EL Haaksbergen
- The Netherlands
-
- New versions are available from the same address : just send some money
- to cover postage and a self-addressed envelope containing a 3.5" disc. As
- this application is under continuous development, you are very likely to
- get a more recent version !
-
- Happy imaging !!!
-
- _______________________________________________________________________________
-
- !!! NOTE !!!
-
- You may NOT change this application or use ANY part of it in other products
- without my approval. You may spread it freely (with *ALL* files included), but
- not for any profit. This software is provided 'as is'. Using it is entirely at
- your own risk.
-
- _______________________________________________________________________________
-
-