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[Image Reduction] menu

[Bias Frame / Dark Frame / Flat Field...]

This command performs a bias subtraction, dark subtraction and flat field correction of the active image (Light frame).

[Subtract Bias Frame]

To perform a bias subtraction on each frame, check this checkbox, and specify the bias frame in [Bias Frame Image].

[Subtract Dark Frame]

To perform a dark subtraction, check this checkbox, and specify the dark frame in [Dark Frame Image].

[Apply Flat Field]

To perform a flat field correction, check this checkbox, and specify the image file of flat frame (refer to Tips) on [Flat Field Image].
To perform a dark field subtraction to the flat frame, check the [Subtract Dark Frame of Flat Field] checkbox, and specify the dark frame image for the flat frame in [Dark Frame Image].

Notice

Level adjustments can be preformed before bias subtraction, dark subtraction and flat field correction. All other processing should be preformed after bias subtraction, dark subtraction and flat field correction

Notice

The pixels with count values below 0 caused by dark subtraction will be given a count value of 0. Some control software of cooling CCD cameras, avoids negative values by adding a constant value (ex. CCDOPS made by SBIG). So, even if you use the same image for a light frame or a dark frame, the result may be different from the result produced by Makali`i.
If a flat frame has pixels with values of 0 or less, the values in the result will be the same as the values in the original image.

Tips

You can perform a bias subtraction and a dark subtraction to the flat frame at the same time as you perform the flat field correction to the active image by using [Subtract Bias Frame] and [Subtract Dark Frame of Flat Field].
You can also use the [Bias Frame / Dark Frame / Flat Field...] command to create a flat field with a bias subtraction and a dark subtraction preformed. (Open an image on which a bias subtraction or a dark subtraction has not been preformed. Then check the [Subtract Bias Frame] checkbox and [Subtract Dark Frame] checkbox in the [Bias Frame / Dark Frame / Flat Field] dialog. Specify the dark frame and bias frame and click the [OK] buton.)

Tips

To apply bias subtraction, dark subtraction and flat field correction to multiple images, you can perform a batch process using the [Batch[Bias Frame / Dark Frame / Flat Field - common...]] or [Batch[Bias Frame / Dark Frame / Flat Field - individual]] command in the [Image Reduction]menu.

[Subtract Over Scan Region of Bias Frame...]

This command performs a subtraction of the over scan region of the active image (Bias Frame).

[Over Scan Region]

Specify the over scan region here.

[3-SD Clipping] checkbox

Check here to subtract over scan region by 3-SD clipping.

[Batch [Bias Frame / Dark Frame / Flat Field - common...]]

This command modifies images using the same set of bias, dark, flat images.

[File] list

This is the list of images that the processes will be performed. All open images are added to this list automatically.

[Remove] button

This command removes a selected image from the list.

[Add] button

This command adds an image to the list.

[Bias Frame]

Check this checkbox to turn on and off the bias subtraction function.
[Bias Frame File] Pull down to choose a bias frame image used recently.
[Search...] button: Specify the bias image file.

[Dark Frame]

Check this checkbox to turn on and off the dark frame subtraction function.
[Dark Frame File] Pull down to specify a recently used dark frame image.
[Search...] button: Specify the dark image file.

[Flat Field]

Check this checkbox to turn on and off the flat field correction function.
[Flat Field File] Pull down to specify a recently used flat field image.
[Search...] button: Specify the flat image file.
To perform a simultaneous dark frame subtraction to the flat frame, check the [Dark Frame of Flat Field] checkbox and specify a dark frame image for the flat frame in the [Dark Frame File].

[New Files]

Select how to handle the processed images.
[Open without Save] Open the results in windows without saving them. If the processed image is already open, the result will be displayed in the same window.
[Save] Saves the results by overwriting the original images.
[Save As] Saves the results using the same names as the original, but placing in another folder.
[Search...] button: Specify the folder where the images will be saved.
[Add a string to all new files] checkbox: Adds a text string to the beginning or end of the file names of the processed images.

[Batch [Bias Frame / Dark Frame / Flat Field - individual...]]

This command modifies images using separate bias, dark, and flat images. Specify bias image, dark image, or flat image for each image you want to process.

[File]

Files in the folder specified by clicking the [Search...] button are displayed here. Drag files from this list to the matrix on the right. Or, select a file in the list and the destination on the matrix and click the [>] button to put a file onto the matrix.

In the Matrix you can use the Ctrl+C (Copy), Ctrl+V (Paste), and DELETE (delete) key to copy, move and delete file names. You can also drag files from one matrix to another.

[Search...] button

Specify a folder to display the contents on the list.

[Image]

Drag the image you on which want to perform bias subtraction, dark subtraction, or flat field correction from the list.

[Bias Frame]

Drag the bias image from the list.

[Dark Frame]

Drag the dark image from the list.

[Flat Field]

Drag the flat image from the list.

[Dark Frame of Flat Field]

Drag a dark image from the list to perform a dark subtraction to the flat image.

[Save As]

Specify the file name to save the image in after processing. If no name is specified, the file name of the [image] will be used and the original image file will be overwritten.

[File]

The name of the file selected on the matrix is shown here (with full path) and you can edit it manually. Use this function to change the name of the save file.

[After Processing]

Select what to do after processing images.
[Save Only] Save every file after processing.
[Open after save] Save and open every file after processing.
[Open without Save] Open the results in windows without saving them.
[Add a string to all new files] checkbox: Adds a text string to the beginning or end of the file names of the processed images.

[Open Table] button

Opens a comma separated text file and copies the content to the matrix. The text file has to use a comma to separate the sequences and use a Return to separate lines. The data needs to be laid out in the same order as in the matrix. 
One example:
aaa.fits, bbb.fits, ccc.fits, ...
ddd.fits, eee.fits, fff.fits, ...

[Clear All] button

Clears all the file name on the matrix.

Tips

When using the same bias, black and flat images to all images, you should use the [Batch [Bias Frame / Dark Frame / Flat Field - common...]]] command instead of this command.

[Batch [Subtract Over Scan Region of Bias Frame...]]

This command performs subtractions of the over scan regions of multiple bias images.

[List] list

This is the list of the images that will be subtracted. All open images will be added to the list automatically.

[Remove] button

Click this button to remove the elected image from the list.

[Add] button

Click this button to add an image to the list.

[Over Scan Region]

Specify the over scan region here.

[3-SD clipping] checkbox

Check here to subtract over scan region by 3-SD clipping.

[New Files]

Select how to handle the processed images.
[Open without Save] Open the results in windows without saving them. If the processed image is already open, the result will be displayed in the same window.
[Save] Saves the results by overwriting the original images.
[Save As] Saves the results using the same names of the original, but in another folder.
[Search...] button: Specifies the folder the images that will be saved when using the [Save to other Folder] command.
[Add a string to all new files] checkbox: Adds a text string to the beginning or end of the file names of the processed images.