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Using the Programme

Loading an image:

When the programme starts, you will see a very simple menu displayed at the top.

Click on the file menu to open it

and select Open to open an image file on your hard disk. When you have finished click Apply, and then you may save your result using SaveAs preferably to a file with a new name so as not to overwrite the original. You will be warned if you try to do so. You may save to a variety of different file types other than that of the input file. If the type of image file supports it (JPEG & TIFF), an internal flag will be set which identifies the file as having been treated. Apply  never modifies the original image. This must be done explicitly with SaveAs.

The file dialog boxes show a little preview image when an image file is selected if it belongs to one of the many file types supported by the programme. There is a small check box   which controls whether or not this preview is displayed. Uncheck it if you plan to open a very large file so that loading is faster. When hovering over the file name with the mouse, the size, type and camera details (if available) are shown in a little balloon .

When you double click on the name of a desired image or on the open button after selecting it, the image chosen will be displayed so that you can see all of it.

A reduced resolution image is displayed at first so that all operations are displayed quickly. 

If an image has already been treated, and if it is of a type which permits recording the internal flag above, you will be warned if you try to reprocess it.

Batch image loading and processing:


Only those images which contain enough information so that the make, camera, lens and focal length are uniquely determined by the internal data in the image can be processed automatically.  You can let the programme decide which characteristics are needed simply by opening and treating a single file containing the camera data in the normal Open way. The settings appear in the drop-down combo boxes in the right hand frame. 

A little checkbox marked when checked, enables transfer of the data to the batch processing code. You must check it after you have verified that the make, camera and lens are appropriate for the files which you wil select for  processing. When you start the batch process, only files made by cameras of this type and lens will be processed. Images are not visible during batch processing, but the status bar shows which file is currently being processed and notifies you when it is finished.

To start the process, select from the File menu:

A dialog box which resembles the Windows Explorer pops up:

On the left side you can select a drive and a directory or sub-directory. All the files in the directory are shown to the right. You can select any number of these by clicking on the first, then holding down the Shift buttin while clicking on the last. Clicking OK starts the batch processing of all the selected files. When the process has finished, the result files are written to the chosen directory.  The resulting files have the letters "-RC" inserted in front of the file extension to distinguish them from the originals which are not overwritten. Files previously processed which already have this identifier will not be processed again. Files processed with the stand-alone version of PTLens which have "_pt" in front of the extension are also ignored.

If you want to process JPEG files and set the image quality to a value which is less than the value in the original file, you can choose this by moving the slider:

which appears only when JPEG files are selected. Please note that JPEG files are irreversibly compressed. Hence, if you set the value to one which is higher than in the original, the original value will be used regardless of the slider setting.

The programme records the directory chosen, so that when it restarts, you may pick up where you left off the last tim. If you wish to go to a collection of files which is not visible, click on the "Desktop" button, and this will enable you to select a folder from anywhere on your machine or on a network.


When you have a camera with more than one interchangeable lenses, and if some of those lenses have common focal length ranges and common minimum or maximum F-numbers, , it is not always possible for the programme to identify the required data uniquely. In this case, you should copy the image files by lens type into different directories and process each of these separately. This is because only the focal length and F number used to create an image is recorded.  You may need to note the image numbers assigned by the camera after such a lens change in order to be able to do this.

Loading an image from the command line:

If an image file name of one of the supported types is given on the command line, the programme RadCor.exe will open it without using the dialog. This feature permits spawning RadCor from other programmes or speeding up repeated testing with the same file. It may also be used in scripting operations. However, only default or previously used values will be applied.

Navigating with the mouse:

If you wish to enlarge the image, click with the left mouse button or use the wheel if your mouse has one:

If you hold down the left mouse button, you can also drag the image to see other parts of the enlarged version.

If you wish to return from the enlarged version to the reduced resolution version, right click. Zooming is possible only when the Profile or Radial buttons are active. When Chromatic is active, special rules apply as described in the section on Chromatic Correction.

You can also navigate using the small navigation window.


If vignetting is present in the image, correct this first before correcting distortion. You will see two track bars which you can attempt to adjust to equalize vignetting in the corners of the image:

The mid-point option controls the area to which the correction given by the amount slider is applied.  

After the vignetting check box is checked, moving one or the other bar immediately modifies the whole image as well as the sampled version if in Radial mode. Otherwise, vignetting is not applied to the image but the values available do change. If vignetting has been changed, then this is carried over when Apply is clicked to affect distortion. Neither Apply nor Vignetting affect the original file until a SaveAs is carried out.

Radial Distortion Correction:

If your camera's profile has been automatically selected with all option boxes filled from the data contained in the file, click on 


to apply the distortion correction to the image in memory, or click on 


to undo the correction.  

You can clear an image, reload it and reset all the programme's parameters to their defaults by clicking on

The camera's horizontal field of view (HFOV) is shown in for users of PanoTools or PTGui if the image file contains the necessary information needed to compute it. If clicked with the mouse, it's value may be copied to the clipboard and pasted into those programmes. It can not be changed.

If your camera's profile is not available, but you have followed the manual correction instructions and saved your own profile, you may apply this to the image by clicking on the Radial option button and then on the Custom menu item   to open a saved profile file.


will select bi-linear interpolation. It is turned on by default. This option slows down correction on very large images noticeably on older machines and may be turned off if desired, but the image may have jagged lines.

ICC Profiles and 48 bit (3 x 16 bit) Tiff images 

Radcor will load, process and save Tiff files containing ICC profiles, and it will also load, process and save Tiff images with 48 bit colour using the profile of the input if  the check box is checked.  Loading and saving is somewhat slower than when this option is not used. Radial correction of 48 bit images is not perceptibly slower than the correction of a 24 bit image. Interpolation is always used.  48 bit output may be turned off by unchecking the box before saving a treated image.  The output image will then have 24 bit (3 x 8 bit) colour resolution.

When ICC/48 bit has been selected, only Profile mode is available and the Radial and Chromatic buttons are disabled. If  your camera and lens profile is not available, you need to make a special profile. To do this, load the 48 bit image with the button unchecked and without attempting to apply any correction, save it with a different name name. It will automatically be saved as a 24 bit colour image. Then load this image which can then be radially or chromatically corrected to create a custom profile. The programme will warn you that the image has already been corrected. Ignore this warning and continue. Following the manual correction instructions, save the custom profile. Then reload it when you want to correct any 48 bit image made with the same camera, lens and focal length. If you use different focal lengths, you will need to create a new custom profile for each.

Saving the corrected image:

This correction is applied permanently to the image file on the hard disk only when you click on the SaveAs menu item, and you are warned if you try to overwrite the original file.  You may save to any one of a large variety of file types. For some of these, advanced options are made available if you click on  the button. These include setting the degree of compression of JPEG files for example. A dialog:

pops up permitting you to set the options. If you click on the box, you can see how changing one or more of the parameters available will affect an output image. For some file types such as Jpeg2000, this interaction may be too slow, and it is recommended that you leave the box unchecked and click on the button after making a change and before you click on .  The parameter change is retained for as long as the programme is open, so this operation need be done but once before processing a series of files.  The saving operation does not become effective until you click on the button when the file will be written to disk. If a file of the same name exists, you will be warned before the programme overwrites it, and you may cancel the saving operation if you wish.

Please note that camera data is included only with JPEG and TIFF files if the camera supports this feature. The programme does not add this data, it only reads it if present in order to get a profile automatically. 


If files are saved in any other format but JPEG or TIFF, all camera data in the EXIF header of the input file is lost.

Programme Restart:

When the programme closes, it writes any available camera information to the Windows Registry, and when it is reopened, the previously read parameters are shown even before an image is loaded. This information is written separately for each user of a machine if there are multiple users. If an image with new information or from a different camera is loaded, then the data in the Registry is overwritten.

Test Data:

A test image, Test_Grid.bmp, is available on the installation directory to enable you to experiment with some of the programme's functions. It is a neutral Windows bitmap which contains no camera or lens data. By choosing a manufacturer, camera, lens and focal length from the available profiles, you can observe the effect on the test image after clicking on Apply.