New features of version 3.71 (September 21, 2002)

The speed of command PREGISTER (registration of the planetary images by a technique of correlation in the Fourier domain) was increased by 30%. The speed of command T_SELECT was increased by 20%.

During the one shot acquisition of a webcam image (Webcam menu) the program return the levels of maximum intensity pixels and minimal intensity pixels in the 3 colors plans. This is practical to adjust the parameters of acquisition so for example not saturating (no pixel having an intensity exceeding level 255 with a webcam 8 bits).

The Webcam acquisition dialog box (Webcam menu) accepts now the colors images as well the long exposure with the modified webcams Vesta Pro (Vesta SC, see for example the page of Sylvain Weiller):

In continuous acquisition webcam mode, the program displays in incrustation in the current image the drift of position of the most brilliant star of the field in pixels/minute compared to the first captured image. The time passed in minute since the realization of the first image of the sequence is also displayed. These parameters are useful to check the polar alignement of a telescope. These new possibilities are described in the lesson 24 of the Iris help.

Moreover the AVI film acquisition dialog box from a webcam (finely Webcam, menu, Video captures... command) facilitates the management of the file names. In particular, it is possible to increment the name of the files automatically. The inputs of the parameters of the film duration of and frequency of the images were also gathered on this dialogue box for a better comfort of use. For more details, click here.

Command SCAN is equipped with the possibility of multiple closings and openings of the shutter throughout acquisition. For more details, click here.

New T-TOOLS commands

Convolution by Gaussian of the trichromatic image defined by the file R, B and B. Equivalent to command

Copy the three images having for name R, G and B respectively in files # R, # G and # B.

Carry out the opposite operation of
T_STORE : restore in the files image R, G and B the contents of file # R, # G and # B.

Display a color image color from the files images R, G and B.

Display a color image starting from the files images R, G and B, but applies a unsharp masking filter with each components as a preliminary. Same parameters as command

T_SCALE [ OPTION ] [ FX ] [ FY ]
Change the scale of a trichromatic image defined by the files R, G and B. Same parameters as command

Other commands

Calculate the Laplacian of the image in memory.

Useful for the representation of the spectral data. Colorize with the rainbow colors the image [ NAME ]. The coloured distribution is realistic and takes into account which the first pixel on the left is with the wavelength [LAMBDA1] and which the last pixel on the right is with the wavelength [LAMBDA2].

SCALECOLOR2 [ R ] [ V ] [ B ]
Adjust the respective levels of the images [ R ], [ G ], [ B ] so that their intensities are identical on average in a zone of the image defined as a preliminary with the mouse. More precisely, Iris multiplies the images [ G ] and [ B ] by a distinct coefficient and their additions a constant to equalize them with the image [ R ]. This command is very practical to carry out the chromatic balance of the planetary images (click here  for an example). For the stellar images it is necessary to employ command