Edit Pixel Mask
The Edit Pixel Mask command is used to view or input the coordinates of bad pixels A bad pixel list is used by the Apply Pixel Mask command to repair isolated hot and cold pixels (to learn more, see Working with Pixel Masks, below). The Pixel Mask Editor contains a data grid that lists pixel coordinates. Use this tool to create new pixel masks or to review and edit masks created using the Create Pixel Mask command. If working with defects larger than isolated pixels, consider working with a blemish mask (see the Edit Blemish Mask and Apply Blemish Mask commands).
Mira pixel masks use a .pxm file extension.
The Edit Pixel Mask command opens from
the Image Window > Process > Calibration menu and
button
on the Main
Toolbar. The "immediate" form, shown first, opens
when an image or image set is displayed in the top-most window. The
general form can be used to select source images from folders,
windows, or by matching templates.
|
Edit Pixel Mask Properties |
|
|
|
Click this button to open a file browser for selecting the pixel mask from a file. The path of the open file appears to the left, in the large text field labeled Pixel Mask File. |
|
|
Click this button to save the pixel mask to a file. The file name will have a "pxm" extension. |
The dialog above shows pixel coordinates loaded from the file BL-CAM.fts (this is a modified version of the installed sample image). The pixel mask was creating by running the Create Pixel Mask command on the source image with the High Threshold set to 10 and Include Pixel Values in the Mask File checked.
After changing the pixel notes descriptions or adding new ones, the mask can be saved back to its file or to a new file. Entries in the Notes column are optional. You can also use the [Go To >>} button to locate mask coordinates in the source image. To do this, open the source image and place it on top. This dialog interacts only with the visible image in the top-most Image Window.
The Pixel Mask Editor contains a data grid that lists the (column,row) coordinates of each mask location. The currently loaded pixel mask file is named in the edit field at the top of the window. Pixel mask files have a pxm file name extension. Several important commands related to the data grid are located in a right-click context menu as shown below. To delete all values in a row, highlight the row and then right-click to open the menu and choose Clear selected cells.
Enter the X (column) andY (row) coordinates for each pixel location on a separate line of the table. Adding text to theNotes column is optional. In the example above, this contains the pixel value that was flagged as a bad pixel for inclusion in the mask.
The editor adds lines in chunks of 100. If you run to the end of the buffer, right click on the table to open its context menu and select Append Rows. Then continue entering mask data in the new rows.
When you are finished editing the the pixel
mask, click 
to save it to a file.
Click 
on the right end of
the Pixel Mask File field. Select the
pixel mask file and click [Open] to
load the pixel mask.
Edit (column,row) pixel coordinates as needed...
When you are finished editing the the pixel
mask, click to save it to a file.
In the context of cosmetic repairs, a pixel mask is a collection of point coordinates that describe bad pixel locations in an image. When a pixel mask is applied to an image, the value at each mask coordinate is replaced by a value obtained from the neighboring pixels. This technique is used to repair defective pixels or "hot" pixels caused by thermal noise in CCD images. If the bad pixel locations do not change, then the same mask can be used for many images on different occasions.
A Pixel Mask is usually stored in a file with a pxm extension, likeMy Pixel Mask.pxm, although txt is also possible. Each line describes the coordinates of a single pixel. The Notes column holds an optional comment.
|
Note |
Remember that coordinates in Mira are 1-based, meaning that pixel (1,1) is the origin of the image array. See Image Coordinate System and Pixel Coordinate Definition. |
Repairing Artefacts and Cosmetic Defects, Create Pixel Mask, Apply Pixel Mask, Edit Blemish Mask, Clean Image Set, Image Coordinate System
