DBHashImage()

Description

DBHashImage() is used to compute the hash value of a window of imagery on a supported database.

Call Signature

int DBHashImage ( int/string filespec, int channel_num [, int x_offset, int y_offset, int x_size, int y_size] )

Return Value

int

A integer between 0 and 32767.

Arguments

int/string filespec:

This can either be the handle returned by DBOpen(), or the name of an open file.

int channel_num:

Input channel number.

[int x_offset]:

If this argument is present, this is the X offset to the first desired pixel on the requested scanline. This is zero for the very first pixel on the scanline.

[int y_offset]:

If this argument is present, this is the Y offset to the first desired scanline. This is zero for the very first scanline in the file.

[int x_size]:

If this argument is present, this is the width of a window of data in pixels.

[int y_size ]:

If this argument is present, this is the height of a window of data in scanlines.

Remarks

If the channel input window parameters x_offset, y_offset, x_size and y_size are not provided then the whole image is used. The hash value returned is equivalent to the number returned by IMGHASH.

Note: that the input window parameters x_offset, y_offset, x_size and y_size must either be all present or all absent.

See also GDB file functions