Putting what's on the screen into the "Big Array"
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If you have loaded a "Binary File"or "Image File" onto the screen, you will find that it is not yet entered into the "Big Array". If you were to press the "Fourier" button the current contents of the "Big Array" will be transformed and then displayed on the screen, replacing whatever you have loaded. If the "Big Array" was empty for example, you see the screen suddenly go blank. Very disturbing. You must move what you have loaded onto the screen into the big array to do most operations. The buttons shown at the left will do so. However they only enter into the real part. If you want something else you must manipulate the "Big Array" to put the entry where you want it. |
enter 1-0 (E)
This option takes the contents of the screen and places all screen pixels darker than 127 (128 to 255) and enters a 1.0 into the real part of the "Big Array" and enters zero for all others. The imaginary part is set to zero. There are 256 values of gray scale ranging from 0 to 255. So 127 is a mid range gray. After you have made the entry the result will immediately be plotted from the "Big Array" back to the screen. If the real part is being displayed the screen will jump to a black (255) value representing a one and mid gray (127) representing zero.
enter 1-1 (-)
This option is much like the one above excepting that the screen values 0 to 127 are entered as -1 in the real part, instead of zero. The real part when placed back onto the screen becomes black and white (0 and 255). The imaginary part is set to zero.
enter gray
This option puts the contents of the gray scale screen and inters it directly into the "Big Array" the result ranges from 0 to 255. The imaginary part is set to zero. If you have loaded a gray scale image into the screen and click this button you should see little change since white (0) will be entered into the real part as -127 and (255) black will be entered as 127 into the real part. If the loaded image did not have a pure white or pure black the real part will be mapped back with a shift in gray scale. It is very likely that if you have loaded an image file and used the enter gray button, that then you will want to use the "rescale" option to add 127 to the real part. The magnitude will now look like the original image, provided you choose to display the magnitude.
add
Much like the "enter 1-0" except that gray values greater than 127 cause 1 to be added to the real part, otherwise there is no change to either the real or imaginary part.