Cross referenced help %% 1,0:1 %% .1 G.I.P. Help System @2[General] @7[Point Processes] @14[Area Processes] @32[Combining Images] @27[Windows] @28[Icons] @23[Menus] @13[Image Display] @3[Atari Series] @4[Image Formats] @5[SHAREWARE] .2 General Help G.I.P. is a greyscale image processor which can be used to enhance images ( for DTP use for example ) and process images with filters. The program runs on the @3[Atari] range of computers and supports a wide range of @4[image formats] .3 Atari Computers Supported G.I.P will execute on the Atari ST, STE, TT and Falcon. On the Falcon, Multitos is fully supported. All graphics resolutions are supported. Including TRUECOLOUR on the Falcon. .4 Image Formats The following image formats can be processed with G.I.P. @29[TIFF]version 5.0 (.TIF) Compuserve GIF (.GIF) Degas (.PI?) Degas Elite (.PC?) PC Paintbrush (.PCX) Aim Greyscale (.IM) Aim Colour (.COL) Monochrome GEM (.IMG) Hyperpaint GEM (.IMG) .5 Program Information G.I.P is SHAREWARE.If you use this program, please send œ15 to Stephen Found 14 Bybrook Court, Kennington, Ashford, Kent. ENGLAND TN24 9JX Please support SHAREWARE. .6 Area Selection An area of an image is easily defined with the mouse. Simply place the mouse in a window and drag the mouse with the left button held down. Once defined, all processes will only affect the selected area. To delete an area,double click the mouse in the window. .7 Point processes Point processes affect all pixels in an @6[image area] in a uniform way. G.I.P. provides the following processes. @8[Brightness] @11[Contrast] @9[Threshold] @12[Negation] @10[Histogram] .8 Image Brightness This option allows you to add a constant value to every pixel in the image. If the value is negative, the image will become darker. .9 Thresholding This option converts a grey image to monochrome. A value from 0-255 is entered which is the threshold value. A pixel will become white if it's grey value exceeds the threshold and black if not. .10 Histogram A histogram of the image showing the number of occurences of each grey level is displayed. .11 Contrast Contrasting is a point process which improves the usage of the greyscale range within @6[images] A threshold is entered, then the process scans the image from the darkest and lightest pixels to find the range that exceeds the threshold in both directions. All pixels within the resulting range are re-mapped to 0-255. .12 Negation Negation produces a 'negative' of @6[the image]. A threshold value is requested, then the image is negated.All pixel values above the threshold are subtracted from 255. Thus pixels that were dark become light and vice versa. If the entered threshold is 0, the resulting image will be an exact negative of the original image. .13 Image Display Every image loaded into GIP is stored as a 256 level greyscale image. How the image is displayed depends on your current display mode. 2 Colour 64 level dither 4 Colour 64 level dither 16 Colour 16 level grey 256 Colour 64 level grey True Colour 64 level grey .14 Area Processes Area processes are also known as @15[Filters]. Filters are used to 'bring out' various aspects of images. When selected, you will be presented with a scrolling list of available filters. When a filter is selected, it will be applied to the current @6[Image area]. .15 Filters The filters supported by GIP are grouped into the following categories: @16[High spacial] @18[Contrast] @17[Enhancement] @19[Detail] @20[Gradient] @21[Noise removal] @22[Edge detection] .16 High Spacial Filters 4 types of high spacial filter are provided. These filters accentuate the high frequency content of an image. Areas of low frequency are left intact. This has the effect of sharpening areas of an image where the grey values fluctuate and leaving areas of uniform greyness as they were. .17 Edge Ehancement Filters 5 types of edge enhancement filter are provided. Edge enhancement is usually used as a preliminary step to feature @19[extraction], and is typically followed by @9[thresholding]. If overlay is selected, these filters can also sharpen images. .18 Contrast Filters 4 types of 'Roberts' contrast filters are provided.These filters accentuate both the high and low frequencies of an image. .19 Detail Extraction Filters 4 types of 'Laplace' extraction filters are provided.These filters differ from other edge filters in that they are omni-directional, so all edges are highlighted in every direction. Regions of constant or linear intensity become black and regions of rapidly changing intensity are highlighted. .20 Gradient Filters 8 Types of gradient filter are provided, one for each compass direction. Other @17[edge enhancement] filters process edges in 4 directions. The gradient filters are conceptually the same but operate in 8 directions. .21 Noise removal - Median Filter Median filtering uses the values of surrounding pixels to change the value of a central pixel. The values of all the pixels are sorted and the the middle (median) value is selected. The result is that any abrupt change (noise) is eliminated. .22 Edge Detection - Sobel Filter The sobel filter is the only non- linear filter provided. A threshold value is requested which determines the range of grey values to be processed for edges. An overlay option is also provided which enables detected edges to be overlayed on the original image. .23 G.I.P Menus There are 4 menu bars in GIP. Many menu selections have keyboard shortcuts which are shown next to the menu title. The GIP menu allows access to the credits and GEM accessories. The other menus are @24[File], @25[Options] and @26[Print]. .24 File menu Load - Load an image into memory A wide range of @4[formats] are supported. Save - Save an image in IMG or @30[TIFF]v5.0 format. Info - Shows the size of the current image. Help - Where you are now. Quit - Exit to the GEM desktop. .25 Options Menu Scale - Select display scale of the current image @10[Histogram] displays a Histogram of the current image. @8[Bright], @12[Negate], @9[Threshold]and @11[Contrast] select @7[Point processes] @15[Filter], @21[Noise] and @22[Edge Detect] select @14[Area processes]. .26 Print Menu This menu allows the printing of images in Laserjet, Deskjet or Postscript formats. The Postscript format will output in encapsulated postscript. You may output to either the Parallel port, Serial port or to disk. .27 Windows Each image will be displayed in a GEM window when loaded. The top window is the 'active' window and any processing selected will be performed on the image in that window. You may select an @6[image area] to process with the mouse. The image in the active window can be scrolled with the mouse or the keyboard ( Cursor keys ). .28 Icons If the screen resolution is higher than 320 pixels wide, an icon bar is displayed. There are icons for file handling, @7[Point processes] and @14[Filters]. All icons have equivalent menu entries and keyboard shortcuts. See: @23[Menus] .29 TIFF Support G.I.P. Supports TIFF Version 5.0 of the following classes :- TIFF Class B - Bilevel images including 'Packbits' compression. TIFF Class G - Greyscale including 'LZW' compression. TIFF Class P - Palette Colour including 'LZW' compression. .30 TIFF Output G.I.P. Outputs TIFF 5.0 Class G images. You may select either TIFF uncompressed or LZW compression. The output is in Motorola format so some PC contemptible programs may have trouble loading them, although I have tested some images with 'Coral Photopaint' which is one of the few Intel programs that recognise the existance of another processor. ( Inverted snobbery ! ) @31[MORE] .31 TIFF Output I have tried generated TIFF images on the Apple Macintosh (MacPaint), Atari (TruePaint) and the Amiga (Package unknown) and they loaded without problems. .32 Combining Images Images and @6[image areas] can be combined in a variety of ways. Hold down either SHIFT key and press the mouse button.The current image area will be shown as a box. Move the box, with the mouse still pressed, into the destination image, then let go of the button. @33[MORE] .33 Combining Images A dialogue will be shown allowing you to select the combination type The following types are available: ( S=Source Image, D=Dest image ) AND D=S AND D OR D=S OR D XOR D=S XOR D ADD D=D + S SUB D=D - S MULT D=D * S DIV D=D / S MIN D=MIN(D,S) MAX D=MAX(D,S) AVG D=(D+S)/2 OVER D=S .End