Publisher review:digitize - Matlab tool for digitizing images digitize is a user interfase that allows to import image files (.bmp, etc) into MatLab to digitize data from. Previous sessions can also be loaded.Intructions:First load a new image by entering the menu "Load" and clicking on "Load New Image". First the Referennce Points (points on the image whos coordinates are known) must be selected. This is done by entering the "Transformation" menu and then selecting "Add Points".
Left-click on the points reference points and Right-click when finished. Then Right-click on any reference point to enter it's "true" coordinate. When the coordinated for all the reference points have been entered the "Reference Data Complete" is checked inside the "Transformation" menu. To digitize, select "Add Points" from the "Digitization" menu.
You may start digitizing points on the image at any time, but their transformed coordinated are not calculated until the reference data is complete. To see a digitized point's transformed coordinate, right-click on a point. A session .mat file contains:jt,kt - reference points in image axes coordinatesxt,yt - reference points in transformed coordinatesimg - the RGB 'Cdata' of the imagejd,kd - digitized points in image axes coordinatesxd,yd - digitized points in transformed coordinatesR - the transformation matrixThe transformation matrix is used to convert from the image axes coordinate system to the desired coordinate system by entered the "true" of transformed coordinates manually.The first order linear transformation matrix is:R = [sx ry 0;... ry sy 0;... tx ty 1]where s -> scaling, r -> rotation, t -> translationA second and third order fits are also available in the "Transformation" menu. These are useful for distorted images or maps of unknown projection. The drawback is that larger orders requiere more data.Click on "Residuals" in the "Transformation" menu to see the residuals of the reference points. The residuals are defined as the "true" or "given" value minus the calculated value using the transformation matrix. The residuals should be of the order of magnitude of the pixcel size. The pixcel size can be seen by clicking on "Pixcel Size" in the "Transformation" menu. The pixcel size is the horizontal x vertical direction. Note that these are approximate because the image is assumed to be rotated. The directory is automatically changed to the directory of the image file. An image can be loaded directly by using for example:
digitize('ImageFileName.bmp')
digitize is a Matlab script for Development Tools scripts design by alex sanchez.
It runs on following operating system: Windows / Linux / Mac OS / BSD / Solaris.
Operating system:Windows / Linux / Mac OS / BSD / Solaris
digitize script details 
