Click on the menu item to see online help for that function.

File Menu

Displays the File Open dialog box and allows you to select a file to open. Many common file formats are supported, including RAW, HDR and FITS files.

Saves the current image with the same filename. Depending on the type of file, the Save Options dialog box may be displayed.

Displays the File Save dialog box and allows you to specify a different filename for the current image. Depending on the type of file, the Save Options dialog box may be displayed.

Displays the Print dialog box. In this dialog, you can scale the image and drag it around to position it where you want on the paper.

Displays the File Properties dialog box. This gives you some lower-level information on the image file itself.

Exits Astra Image. Sorry to see you go!

Edit Menu

Undoes the last action.

Sometimes, the undo function can take up a lot of memory. The Clear Undo function resets the undo function and frees up memory. This can be especially useful with a 32-bit operating system.

Copies the selection to the clipboard. If there is no selection, the entire image is copied.

Pastes the image from the clipboard into Astra Image as a new image.

View Menu

Zooms in by one zoom step. Can also be done by using the mouse wheel or the F2 key.

Zooms out by one zoom step. Can also be done using the mouse wheel or the F3 key.

This function automatically adjusts the zoom so that the entire image can be displayed at once.

Allows you to manually select the zoom ratio.

Sets the position and visibility of the Adjustments window (the window with Levels, Brightnes, Contrast etc). These settings are preserved across Astra Image sessions.

Displays the Astra Image log with information about what processing has been done, errors and software versions.

Image Menu

Allows you to resize (resample) the image. You can specify the new size in pixel values, percentage, or you can choose from a list of common sizes (640x480, 800x600, 1024x768 etc).

The Resampling Method combo-box lets you choose the algorithm for resizing the image. They are:

  • Nearest Neighbor - very fast and low quality.
  • Bilinear - fast and reasonable quality.
  • Bicubic - moderately fast and good quality.
  • Mitchell - slower and high quality.
  • Lagrange - slow and high quality.
  • B-Spline - slow and high quality.

Removes all color information from the image which produces a grayscale image as a result.

Crop the image to the current selection. If there is no selection, this function does nothing. You can select the area to crop by clicking and dragging with the mouse pointer.

Rotates the image by 90 degrees in the clockwise direction.

Rotates the image by 90 degrees in the counter clockwise direction.

Flips the image vertically, from top to bottom.

Flips the image horizontally, from left to right.

Enhance Menu

Gives you tools to deblur an image that has been affected by linear motion, or is out of focus.

Deconvolution Type

There are several different types of deconvolution that you can choose from. Weiner and Constrained Least-Squares are not iterative and complete quickly but can be subject to noise amplification. Lucy Richadson and Total variation are iterative algorithms, and therefore take longer, but suppress noise more effectively.

Blur Kernel Type

The Blur Kernel is used as a model of what degraded the image. For a sharp image, a Gaussian blur kernel can make the image sharper. For other problems, like out of focus or motion blur, special blur kernels are provided.

Settings

You can set the number of iterations for Lucy Richardson and Total Variation deconvolution. Also, you can set the strength of the deconvolution for some deconvolution types. For Weiner deconvolution, you can use the check box to set whether the preview is updated automatically or not.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the deconvolution on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

Gives you tools to sharpen an image and suppress halos.

Deconvolution Type

There are several different types of deconvolution you can choose from. The main difference between them is how well noise is suppressed. Van Cittert deconvolution is fast and produces an excellent sharpening effect, but can be subject to noise amplification. As we move down the options, the final method is Maximum Entropy deconvolution which is good at suppressing noise, but is slower and may require more iterations.

Blur Kernel Type

The Blur Kernel is used as a model of what degraded the image. For general sharpening tasks, a Cauchy blur kernel is a good place to start. However, experimentation is encouraged as each image is different and so some images are sharpened more effectively with the other blur kernel types.

Settings

You can set the number if iterations in the Settings area. More iterations leads to a stronger result. You can also set the deconvolution strength for some of the deconvolution types, and you can turn on or off the halo suppression.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the deconvolution on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

Gives you tools to both deblur and sharpen images. As this function is not iterative, it often completes faster than other methods.

Deconvolution Type

There is only one option here at the moment :)

Blur Kernel Type

The Blur Kernel is used as a model of what degraded the image. For general sharpening tasks, a Cauchy blur kernel is a good place to start. However, experimentation is encouraged as each image is different and so some images are sharpened more effectively with the other blur kernel types. For other problems, like out of focus or motion blur, special blur kernels are provided.

Settings

You can set the strength of the deconvolution in the Settings area.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the deconvolution on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

Like a more advanced version of wavelet sharpening, this tool allows you to sharpen an image at different scales. Halo reduction can be applied, and different decomposition filters can be used.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the Multiscale Sharpen on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

Allows you to perform simple sharpening at different scales. The main image is updated in real time.

Settings

Drag the sliders to adjust the sharpness of the image at different scales. Sometimes, strong sharpening can result in very white edges and other artefacts. These can be suppressed by checking the Suppress Halos check box.

A classic tool to do basic sharpening. The main image us updated in real time.

Settings

You can change the strength of the effect using the Strength slider. The Radius sliders sets the size of the filter used to blur the image and allows you to sharpen details of different sizes.

Adjust the contrast of an image at different scales. The shadow, midtone and highlight areas can be adjusted individually. Basically, it is usually good to use the Global setting first, then use the Shadows, Midtones and Highlights buttons to fine-tune the adjustment. Note that whenever an adjustment is made with the Global setting, all the other settings are updated.

Sometimes, the Multiscale Contrast tool can produce bright edges or over-sharpened edges. To help prevent this, check the Protect Edges checkbox.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the Multiscale Contrast on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

Adjust the contrast of shadows, midtones and highlights individually. This function can also perform sharpening on textures and image edges. The sliders allow the strength of the adjustment to be set. In addition, you can specify the size of the texture (or details) to be sharpened. The Vibrance slider can be used to enhance the image colors, which can look pale after adjusting the contrast.

Sometimes, strong sharpening can result in very white edges and other artefacts. These can be suppressed by checking the Suppress Halos check box.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the Super Contrast on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

This tool sharpens the really small details in an image without halos. The main image us updated in real time. The slider adjusts the strength of the enhancement.

A classic tool to lighten shadows and darken highlights. The Tonal Range sliders adjust how much is adjusted: a low value means that only the darkest shadows and brightest highlights are adjusted, while a high value means that lighter shadows and darker highlights are also included in the adjustment.

Sometimes, this tool can produce halos. The Halo Reduction slider can suppress these halos.

The Saturation slider can increase or decrease color saturation.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the Shadows and Highlights on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

This tool removes noise while preserving image details. Chrominance (color) and Luminance (brightness) noise suppression can be adjusted separately.

This is a slow function! But it is doing a lot of hard maths to remove the noise while keeping the details in the image. The Quality group allows you to select standard or high quality noise removal. Please note that the high quality noise removal can take a long time.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the Denoise function on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

This tool removes noise quickly and does a reasonable job at preserving image details. The main image us updated in real time. The Noise Level slider is used to adjust the strength of the noise removal. A higher value means more noise removal. The Filter Window allows you to select how many pixels are used in each calculation. A bigger window size gives more suppression, but takes longer to calculate.

Allows you to apply a convolution filter for sharpening, blurring, edge detection etc. The main image us updated in real time. You can also enter a custom filter kernel in the edit boxes.

This function lets you apply a minimum, maximum, medium or mean filter to the image. The main image is updated in real time. The Window Size combo box lets you select how many pixels are used in the calculation.

Make a high dynamic range image into something that can be displayed easily. The main image us updated in real time.

Make a high dynamic range image into something that can be displayed easily. Adjusting the Exposure and Gamme should produce a standard image. The Sharpness of the image, as well as the Saturation and Black Point can be set individually.

Preview Area

In the preview area you can drag the image around and run a preview on a 500 by 500 pixel area. Clicking the Preview button runs the Tone Mapping on the preview area with the current settings. Using the mouse wheel lets you quickly change before and after images.

Apply different mathematical functions to each pixel in an image. The main image us updated in real time. Some functions require a parameter which can be entered in the Value edit box.

Process Menu

Combines three grayscale images into a color image. Each grayscale image represents a color channel: red, green or blue. The Auto Align button will try to correct for any linear translation between the images.

Combines four grayscale images into a color image. Three grayscale images represent a color channel: red, green or blue, and one grayscale image is a luminance image.

If you click on an area of the preview image that has some details, and then click the Align Images button, any linear translation will try to be corrected.

In the Settings tab, you can choose whether you want to use LAB or HSL color space when creating the color image. You can also specify an alignment search area as well as whether to try to normalize the background or not.

Help Menu

Shows this page!

Allows you to enter your license key and see the current activation details.

Displays the About dialog box where you can see the current version of Astra Image, and whether you are using the 32 or 64-bit version.