Amiga Image ViewEr version 1.7 April 1994 Role : Displaying 256 colors pictures on a basic Amiga . ------ Copyright : ----------- AIVE is (c) 1994 Laurent Vivier . It may not be sold in commercial goal without my written approval . It can't be distributed for a fee which exceed of 15 French Francs (3 US dollars) . It is forbidden to make a profit through the distribution of this software without my written approval . It can't be distributed without its documentations . Thus, Files "AIVE", "AIVE.docF", "AIVE.docE" can't be split . This software is freeware . You can contact me for help or some questions, suggestions . (or to correct this document) Disclaimer : ------------ I accept no responsability for the use or misuse of this software, and for dammage it could produce. Use at your own risks . Contact : --------- postal address : Laurent Vivier Avenue General De Gaulle 38380 Saint Laurent du Pont FRANCE e-mail until june 15 1994 : Laurent.Vivier@ufrima.imag.fr Laurent.Vivier@imag.fr Supported formats : GIF87a, GIF89a (interlaced or not), IFF . ------------------- The Graphic Interchange Format(c) is the Copyright property of CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe Incorporated. Use : ----- We can use AIVE from CLI (or Shell) or Workbench. Supported options from CLI : ---------------------------- We give file name and options from parameters command line . AIVE writes possible options if we run it without parameters ! AIVE name [hire|lore|ehb][nolace][grey|gray][scale][color #colors] [width w][heighth][ratio a/b] [dither none|fs1|fs2] [smooth none|gs1|gs2] HIRE,LORE,EHB : to choose graphic mode to use HIRE : high resolution LORE : low resolution EHB : Extra-Half-Bright the default mode is HAM . COLOR n : n is the number of colors tu use (>= 8, default is the maximum). With the option GREY, n is the number of grey levels . NOLACE : by default it uses interlaced mode, this option disables it . GREY : to display picture in grey levels (16 colors, HIRE) SCALE : the size of the picture is modified to fit in the screen . WIDTH w : w is the maximum width of the screen HEIGHT h : h is the maximum height of the screen RATIO a/b : bending ratio of the screen : x is the width of a pixel, y the height, then : y = x * (a/b) . default : a/b = 1/2 LORE (= HAM, EHB) = 1/1 LORE and NOLACE = 1/1 HIRE = 2/1 HIRE and NOLACE that values are not best . But they are dependant on your screen . Compute them . DITHER NONE : no dithering FS1 : unidirectional dithering, the error is propagated only on the row FS2 : bidirectional dithering, the error is propagated through rows and columns (option by default) The method used is Floyd-Steinberg. SMOOTH NONE : no smoothing (option by default) GS1 : filter used to smooth row is a 1 dimension gaussian filter GS2 : filter used to smooth rows and columns is a 2 dimensions gaussian filter Note : I have added smoothing option because some pictures which have already suffer a dithering (like a conversion from JPEG to GIF) are very ugly in HAM mode. With smoothing I try to inhibit the previous dithering. More, 2 dimensions smoothing can avoid flicking in interlaced mode. Example : We want to display the picture cindy.gif (800x600) in a standard display and using bidirectional dithering and 2 dimensions smoothing. aive cindy.gif scale smooth GS2 We note bidirectionnal dithering and HAM are by default. Same picture, in 100x100 screen and without smoothing or dithering, with a ratio of 5/11 between pixel width and height (in low resolution mode) : aive cindy.gif lore dithering none ratio 5/11 width 100 height 100 Tool Types from Workbench ------------------------- To run AIVE from workbench, select AIVE, then press shift key and do a double-click on icon of the file to display. Tool types give options to aive from Workbench, like parameters from CLI. Tool types are located in icons of files. We can modify tool types of a file by selecting this file with mouse and selecting "Information" (Right-Amiga I) in workbench "Icons" menu. We can add tool type with "New" and delete with "Del". First, AIVE reads tool types in its own icon, then in the icon of the selected file. Thus, tool types in the icon file have priority. Tool types of the picture can disable tool types of aive icon. Tool types are : MODE=HAM to select HAM mode MODE=HIRE high resolution MODE=LORE low resolution MODE=EHB Extra-Half-Bright COLOR=n where "n" is colors number (or grey levels) INTERLACED=YES to select interlaced mode INTERLACED=NO otherwise GREY=YES to select grey levels (GREY can be GRAY) GREY=NO otherwise SCALE=YES to select autosizing SCALE=NO otherwise WIDTH=w where "w" is the maximum width of the screen HEIGHT=h where "h" is the maximum height of the screen RATIO=a/b where a/b is the pixel ratio between pixel width and height DITHER=NONE to disable dithering DITHER=FS1 to select unidirectional dithering DITHER=FS2 to select bidirectional dithering SMOOTH=NONE to disable smoothing SMOOTH=GS1 to select unidirectional smoothing SMOOTH=GS2 to select bidirectional smoothing The default values are : MODE=HAM, INTERLACED=YES, SCALE=NO, GREY=NO, DITHER=FS2, SMOOTH=NONE. WIDTH, HEIGHT, RATIO, and COLOR have standard values of the selected mode. Note : we can insert spaces between words and "=". Example : if tool types of AIVE are : MODE=HAM, GREY=NO, INTERLACED=YES and tool types of picture are : MODE=HIRE, GREY=YES, RATIO=10/11 the used tool types will be : MODE=HIRE, GREY=YES, INTERLACED=YES, RATIO=10/11, DITHER=FS2, SMOOTH=NONE. Interface : ----------- When we run AIVE, a window is opened (from workbench, a second window is opened to write error messages). We find in the name of the picture, its kind (GIF87a, GIF89a, IFF ...), its size, and the progression of the decoding . A gadget "Stop" permits us to stop the operation, and to quit the program . The keyboard shortcut is "ESC", it's enable only if the window is activated (and then, not the screen where is the picture !) . You can swap screen with [Left-Amiga m], you can push workbench screen in front with [Left-Amiga n]. Note : Under OS2.0, you can display picture bigger than your screen . To move it use the standard system operation : [Left-Amiga Left-Mouse-Key] and move mouse to move picture . Under OS1.3, picture is automaticaly fitted in the screen . Technical : ----------- AIVE uses Floyd-Steinberg dithering, convolutions, CIE luminance weight, and custom algorithms, and no floating point operations . For more details, refer to "AIVE.docF" (it's time to learn French ! All my apologies) Possible evolutions : --------------------- - gamma correction (why ?) - a printer option - a save option - PCX and BMP formats, perhaps JPEG (I don't think !) - a better human-computer interface under intuition Compatibility : --------------- AIVE was developed under OS1.2, then OS2.0 . It may be run under all systems . We can meet problem with graphic cards : I don't use the "WritePixel" function from "graphics.library", but I write the value in memory . The test activity was made on my A500 : mother board rev 5a, OS2.0, 2 drives DDDS, 512 FAST, 512 CHIP . Known bugs : ------------ - scale doesn't run properly with an interlaced GIF picture - smoothing doesn't run with grey levels mode - sometime unapropriate color pixels on the right border (That's all, I hope !) Thanks to : ----------- Frederic Elisei Archimede user of genius, who inspires me Franck Lyonnet Idem Look at their JPEG viewers for Acorn Archimede 5000, speedy than all GIF viewer on Amiga (500 !) . Roger Wilson who written a paper on his software ChangeFSI . Steven A. Bennet author of GIF decoder which inspirates me . Cindy Crowford to her beautiful body (a good motivation !) . UFR Informatique where I have discovered the internet world . et mathematiques (Thanks to system administrators) appliquees de Come studying in Grenoble Grenoble (the country is beautiful : its ski resorts, its lakes) History ------- January 1994 version 1.0 First release January 1994 version 1.2 corrects 2 little bugs : - System alert with an odd picture width - little dithering saturation March 1994 version 1.5 Corrects other bugs : - system alert when using grey and low resolution at the same time - impossibility to made grey levels with less than 16 levels . Evolution : - optimizing of dithering (close to 2 or 3) - scaling April 1994 version 1.7 Corrects bug : - now, we can display IFF pictures with less than 256 colors ! - detects if IFF picture is compressed by line (and not on all picture, generally ".pic" files, so we can't display it) Evolution : - optimizing of IFF loader - workbench interface - possibility to disable dithering - implementation of 1D dithering - smoothing Author : Laurent Vivier --------