ChromaPIX 101 Quick-Start 20-DEC-97 last changed: 19-JUN-98 Receiving SSTV Pictures ----------------------- Connect audio from your radio speaker to the line input on your sound card and adjust the sound to a 'normal' listening level. Tune to 14.230 or 14.233 MHz ad listen for anyone sending Slow Scan TV signals. Initially adjust the radio tuning for a 'natural' sounding voice signal. This will normally get you very close to the correct SSTV frequency. ChromaPIX will auto adjust for mistuned SSTV tones but it is best to be as close as possible. If you have more than one front panel displayed press the SSTV Active/Inactive button located in the lower right corner of the front panel you wish to receive on until the button says "SSTV Active". At this time you should see the 'Level' meter bouncing and a display on the Spectral scope. You should now press the [ Auto Rx ] button. When the station starts the SSTV transmission ChromaPIX will automatically detect the correct mode and will go from Auto Rx to Receive operation as indcated by the LED on the receive button. If you fail to see an indication of input signal on the 'Level' meter you may have to use your sound card control panel to make sure that the 'Line Input' is enabled and the 'Line' input level is set between 50 and 75% of max. While the sound level is not critical, you must have some sound to receive SSTV. Normally since there is only one sound card in your system only one front panel at a time can be used for SSTV transmission or reception. Other front panels can still be used to cue up images and can be instantly connected to the VM by pressing the SSTV Active/Inactive button located in the lower right corner of the panel. The latest version of ChromaPIX also supports full duplex SSTV operation using two front panels. While the 'Active VM' front panel is in receive mode you can transmit using an inactive VM front panel from the [Exp] tab -> [Duplex TX] button. Note: During SSTV reception or transmission other controls on the front panel are disabled until the current SSTV operation is finished. This is to avoid accidental image corruption. Tuning SSTV Signals ------------------- ChromaPIX has two tuning aids to assist in the correct tuning of SSTV signals. The tuning meter measures the tuning error signal to give you an indication of how far you are off frequecy. This error signal is damped so the tuning meter will take some time to respond to input frequency changes. The signal spectral display is often a much faster way of zeroing in on the correct subcarrier frequency. The horizontal axes of the display is calibrated in frequency while the verticle axes repesents signal quantity at that frequency. The horizontal markers, from left to right, are at 1200 Hz (SYNC), 1500 Hz (Black or Minimum color element), 2300 Hz ( White or Maximum color element). Most SSTV signals have a characteristic curve with a single peak at 1200 Hz and a wide amount of activity in the 1500 to 2300 Hz area. When tuning you can often use the sync peak as a marker and slowly move the receiver tuning until the sync 'blip' falls directly on the 1200Hz line. Typical spectral display: _____________ ^ / \ | | | | | | ______/ \__/ \_______ SYNC <--- VIDEO --> Saving Pictures to Disk ----------------------- To save the current picture click on the picture with the left mouse button and drag it ontop of the row of thumbnail preview images below the screen. To save a portion of the current picture draw a 'selection rectangle' using the right mouse button. Then drag the selected area to the thumbnail tray using the left mouse button. Loading Pictures from Disk -------------------------- To load an image you can either double click on the thumbnail preview in the image tray or drag the thumbnail image onto the main screen. To load an image into just part of the screen first draw a selection rectangle using the right mouse button then drag the thumbnail onto the screen using the left mouse button. To add a black border around the image loaded into a selection rectangle press one of the two 'load effects' borders buttons located directly below the screen and on the left side. The far left button generates a single black border while the one to the right of it generates a thicker border. To add 'drop shadows' during while loading a selected area press one of the four 'load effects' shadow buttons located below the screen and to the right of the two borders buttons. Borders and drop shadows can both be enabled for the same load. Starting from the left the four shadow buttons generate: black, grey, transparent, and soft drop shadows. Soft drop shadows are typically the most realistic. Other 'load effects' buttons ( from left to right ) 'live load', allows live positiong of image fragments during load operations, 'clip load', clips areas of the image that fall outside the selection rectangle while maintaining the original image aspect ratio, and 'fit load', scales the image o fit within the selection rectangle while maintaining the original image aspect ratio. Transmitting SSTV Pictures -------------------------- Load a picture, select the desired SSTV mode, and click the "Transmit" button. Pretty easy! Full-duplex operation is possible, *IF* you have a full-duplex sound card and drivers. You can receive in the "active" panel, and use the experimental Full-Duplex TX button in a different panel. Future versions will include RS232 push-to-talk control, and other features. Changing Image Directories -------------------------- The 'image tray' allows you to easily switch between six of your favorite directories by clicking on the tabs along the bottom of the tray area. Different front panels maintail their own 'favorite' directories. To change a tab's directory you can either click the 'folder' button located above the thumbnails or double click on the tab itself. A simple disk navigator will allow you to 'single click' around your disks and directories. A number in the lower dialog area indicates the number of recognized image files found in the currently selected directory. Setting the Number of Front Panels ---------------------------------- Use the preferences dialog under the 'Settings' menu to change the number of front panels. The new number will be used the next time you restart ChromaPIX. Adjusting Pictures ------------------ The area on the left side of the front panel contains four tabed control panels. The image manipulation controls are divided into four catagories: CNTL - common image controls such as Brightness and Contrast sliders, FX - Special Effects, PAINT - paint functions, PROC - traditional image processing filters. Most operations can be limited to an area of the screen by using a selection rectagle drawn with the right mouse button. The standard CNTL control sliders present an active preview on the image. Once the adjustment is statisfactory clicking once on the pictue will 'lock down' the changes and return the sliders to center position. A histogram display below the slider controls indicates the distribution of pixel values in the current image. Undoing Changes --------------- ChromaPIX provides one level of undo operation for most functions. Undo is available under the edit menu. Undone operations can usually be Redone from the same menu. This gives you an easy way to compare two 'before' and 'after' images. (just hit cntl-z to flip between undo and redo) Working With Multiple Front Panels ---------------------------------- If you have the screen area it is usally very handy to run with more than one front panel. As a general rule you may want to run one panel if your screen size is 640 X 480, 2 panels if you are running 800 X 600, 2 or more if you are running 1024 X 768, or 1280 X 1024. ******************************** NOTE! **************************************** The use of more than 2 panels is not recommended under Windows 95. The number of panels used under Windows NT is limited only by the amount of system memory available. With multiple front panels you can; o Load images from one front panel's thumbnail image tray by dragging to the second front panel's picture area. o Drag images from one front panel screen to another front panel screen. o Drag selections between front panel screens. o Use one panel to send and receive SSTV while you work on the second panel.