GB2270604A

GB2270604A - Scanning method and apparatus

Info

Publication number: GB2270604A
Application number: GB9318664A
Authority: GB
Inventors: Darryl Colburn Stein
Original assignee: Gerber Garment Technology Inc
Current assignee: Gerber Technology LLC
Priority date: 1992-09-14
Filing date: 1993-09-08
Publication date: 1994-03-16
Anticipated expiration: 2013-09-08
Also published as: DE4331188A1; FR2695734B1; GB9318664D0; JPH06223175A; GB2270604B; FR2695734A1; JP2801505B2

Abstract

Scanning apparatus (12, Figure 1 not shown) reduces an image on a carrier P to data which is uncorrected for distortion arising during the scanning process. To correct the data the image-bearing carrier P is placed in registration with a panel 40, 42 bearing reference marks 46 of known position for scanning. The reference marks 46 define a reference grid in which the image lies. The uncorrected data from the scanning apparatus 12 includes data for the reference marks as well as the image. Coordinate transforms are created from the known and distorted data defining the reference marks, and the transforms are utilized to spatially map the image data into the reference grid to correct the data for distortion. <IMAGE>

Description

2270604

SCANNING METHOD AND APPARATUS BACKGROUND OF THE INVENTION

The present invention relates to a method and apparatus for scanning an image and generating image data that accurately reflects the original image. In particular the image data is corrected to remove distortion that arises from the scanning operation.

Apparatus for scanning images to reduce such images to data that may be subsequently processed by a computer is old and well known in the art. Also many uses for such scanning apparatus are known. For example, pattern pieces that define the contours of clothing parts, such as parts of shirts, is dresses, pants and other garments, are created by clothing designers as full scale pattern pieces. The pattern pieces are typically cut from tag board, a heavy weight paper or light weight cardboard, and then the contours of the pattern pieces along with critical cutting and sewing points within the pattern are digitized in a scanning apparatus for subsequent manufacturing operations. The first manufacturing operation usually consists of marker making in which pattern pieces are positioned in a closely nested 2 array corresponding to the array of pattern pieces to be cut from a multi-ply layup of sheet material.

U.S. Patents 3,596,068 and 3,803,960 disclose such marker makers. In the next manufacturing operation the pattern pieces are actually cut from a layup of sheet material by an automatic, numerically controlled cutting machine. one such machine is disclosed in U.S. Patent 3,495,492. In both the marker making systems and automatic cutting machines, the contours of the pattern pieces are used in a machine-readable form, typically digital data, for processing and reproduction either as visual images of the pattern pieces or as the cut pattern pieces themselves. The digital representations of the pattern pieces must accordingly accurately reflect the contours of the original patterns created by the clothing designer.

The reduction of a visual image to digital data is also required in many fields other than the garment industry. In each instance an accurate reproduction of the image contours is essential or the data produced will be useless or will lead to manufacturing errors, production difficulties, low quality products or other undesirable results.

The reduction of images to machine-readable or digital data is, as indicated above, well known 3 and typically produced by scanners. The image to be reduced is generally prepared on a sheet of paper by visual or other detectable markings, or the image may be defined by the contours or edges of a pattern piece. A typical scanner may employ a CCD (charge coupled device) camera that is capable of scanning the image in a raster pattern and detecting the contours of the image which are converted to digital data.

Scanners, however, frequently introduce certain distortion into the digital data so that reproduction of the image from the digital data does not accurately reflect the original image that was scanned. Such errors may arise, for example, from is optical distortion in the cameras and imaging system, from mechanical errors associated with the movement of either the camera or the image- bearing sheet carrier during scanning and from electrical signal processing errors. The errors manifested in the scanned data, or the image produced from that data are characterized by stretching or bulging, skewing, shrinking, enlarging or dislocating one portion of the image relative to the others. Such errors accordingly result in dimensional differences between the original image and the image reproduced from the data generated by the scanner.

4 Precision scanners which produce image data with acceptable accuracy are often too costly for many applications. The high costs of such equipment result from the expensive optics and precision drive mechanisms which are required to minimize the optical and mechanical errors that occur during scanning operations.

One solution to such scanner problems is proposed in the text entitled Digital--Image Processing, 2nd Edition, by R.C. Gonzalez, P. Wintz published by Addison- Wesley Publishing Company, Copyright 1987. In Chapter 5 entitled Image Restoration 11reseau marks" produced by small metallic squares embedded directly on the surface of the imaging tube are utilized as tie points that can relate the distorted image after scanning with the original image by means of a series of equations or transforms. In effect the transforms allow points in one coordinate system distorted by the scanning process to be spatially mapped into another, undistorted coordinate grid system. The spatially mapping is possible due to the fact that the locations of the reseau marks embedded in the imaging tube of the camera are precisely known and the images of the marks in scanner data accurately define the magnitude and location of the distortion. While this technique permits the distorted data to be corrected, it also requires a scanning apparatus that is specially constructed with the reseau points. Also the reseau points appear in the scanner data and may possibly obstruct important features of the scanned image.

It is accordingly a general object of the present invention to provide a scanning method and apparatus which produces image data that is corrected for distortion arising from the scanning operation without employing costly scanning apparatus and without the problems discussed above; and/or to provide improvements generally.

According to the present invention there is is provided an apparatus for scanning an image-bearing carrier and generating scanned image data that has been corrected for distortion arising from the scanning operation The apparatus includes a planar member bearing precisely located indicia that are distributed over the surface of the planar member and define known reference points, such as those found in a coordinate grid.

Image scanning means is provided for scanning images on the image-bearing carrier and generating image data which may be distorted due to 6 optical and mechanical errors of the scanning means itself.

The image bearing carrier and the planar member bearing the indicia are overlaid to register the image with respect to the indicia. For example, the planar member may be one panel of an envelope into which the image-bearing carrier is inserted. One of the panels of the envelope is transparent so that the image on the carrier in the envelope and the indicia on the envelope are visible when the envelope with the carrier is positioned in the scanning means during a scanning operation.

Processing means is connected with the scanning means to correct the distorted image data.

The processing means finds the data defining the -- image and the indicia, and transforms the uncorrected image data to corrected data. The transforms used in the correction process are established in accordance with the uncorrected data defining the indicia and the known positions of the indicia within the planar member.

The invention also resides in the method of scanning an image carrier and producing image data corrected for distortion. In the method, a planar member is provided with indicia defining known reference points on the member, such reference points 7 defining, for example, a coordinate grid. The planar member and image carrier are overlaid to place the indicia in fixed registration with the image on the carrier. The overlaid member and carrier are then scanned to produce data that represents the image and the indicia without correction for distortion that arises during the scanning operation. The uncorrected data is then processed to produce corrected data in accordance with the distortion of the known reference points of the indicia in the uncorrected data.

The invention is advantageous for a number of reasons. A primary advantage lies in the ability to carry out a scanning operation and obtain is dimensionally accurate data without using a scanner that is specially designed to adjust the data output for distortion. In other words, a more conventional scanner can be employed and yet accurate data is produced. Furthermore, before the scanning operation is performed, the registration of the indicia defining the known reference points and the image being digitized can be examined to ensure that critical points within the image are not obstructed by the indicia. In this manner the resulting data will be not only dimensionally accurate but will 8 completely define all critical features of the scanned image.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a scanning apparatus incorporating the present invention and including a large format scanner.

Fig. 2 is a front elevation view of the scanner partially broken away to show the feed rollers and cameras.

Fig. 3 illustrates an envelope and a pattern piece to be scanned by the scanner.

Fig. 4 is a graphic representation of the digital data uncorrected for distortion after scanning the envelope and pattern piece shown in Fig.

3.

Fig. 5 is a flowchart of the scanning and data processing method performed by the scanning system of Fig. 1.

Fig. 6 is a graphical representation of a polygon and illustrates one technique for analyzing the circular reference marks to establish their centers and to confirm their identity as reference marks.

Fig. 7 illustrates the algebraic expressions utilized by the data processor for 9 identifying the centers of the circular reference marks as represented in Fig. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Fig. 1 illustrates a scanning system, generally designated 10, which includes a large format image scanner 12. The scanner advances sheettype image-bearing carriers through the machine and progressively scans the images on the carriers to generate digital data representing the scanned image.

The digital data is fed to a data processor 14 which is a conventional PC computer. In accordance with the present invention the scanner 12 is a conventional scanner that does preliminary processing of the digitized data for purposes of synchronizing, is normalizing and possibly compressing the data without attempting to correct the data-for mechanical, electrical or optical distortion that can arise during a scanning operation. One such scanner of this type is available from Vidar Systems Corp. of Herndon, Virginia.

As shown in Figs. 1 and 2, the scanner 12 is supported by a pair of upright posts 20, 22 and has a housing 24 containing two line-scanning cameras and lens assemblies 26,28. The cameras collectively view a document to be scanned through an elongated aperture slot (not visible) in the upper portion of the housing. As shown in Fig. 2 the field of view of the camera 26 covers one portion of the aperture slot at the right side of the machine, and the field of view of the camera 28 covers another portion of the slot at the left side of the machine. The fields of view of each camera overlap at the center to be certain that no portion of a document in the scanner is inadvertently missed. The scanner contains processing circuitry to eliminate any duplication of the image data arising from the overlap of the fields of view. The cameras are preferably CCD cameras which scan the surface of the document in a raster pattern through the aperture slot, and the processing circuitry also synchronizes the data from the rasters of each camera to produce data for one image in which the left and right-hand portions are correctly positioned and connected. The scanner may also have other processing circuitry for normalizing the data from each camera.

In accordance with the present invention the document or image-bearing carrier to be scanned is positioned in an envelope 30 shown and discussed more particularly below in connection with Fig. 3, and is placed on a feed tray 32 at the upper side of the scanner 12 in order to pass through the scanner relative to the aperture slot for scanning by the 11 cameras 26,28. For this purpose a pair of feed rollers 34,36 extend between the posts 20,22, and the lower roller 34 is rotatably driven by means of a stepmotor 38. The rotation of the stepmotor and the roller 34 is monitored and fed to the processing circuitry of the scanner 12 in order to identify the position of the envelope 30 in the one direction, designated the X coordinate direction, while the cameras 26,28 detect the image in the envelope 30 in the orthogonal or Y coordinate direction. Thus with the data from the stepmotor and the cameras the processing equipment within the scanner 20 can correlate the X and Y coordinates of the data points in the output of the scanner.

The feed rollers 34,36 are covered with a soft rubber or foam material in order to accept image carriers of different thicknesses. However, due to the covers and the fact that only one of the rollers 34 is driven by the stepmotor 38, skewing and slippage of the image carrier can arise during the scanning process and produce a geometric distortion of the image in the data output.

In accordance with the present invention the envelope 30 shown in Figs. 1, 2 and 3 is composed of two planar panels 40,42 which are joined along at least one side 44 so that an image-bearing carrier, 12 such as the pattern piece P cut into the shape of a shirt piece, can be inserted between the panels for scanning. of course, the panels 40,42 could also be joined along two, three or four sides as long as a slot or opening is provided for inserting the pattern piece P between the panels.

In the embodiment of Fig. 3, the panel 40 which is located closer to the viewer than panel 42 is made of a transparent material such as a clear vinyl, and the panel 42 is a opaque panel having a color or shade contrasting with the pattern piece P. A plurality of reference marks 46 are disposed along the periphery of the panel 42; however, the marks could also be placed on the transparent panel 40.

While crosses and other types of reference marks can be used, the reference marks 46 are comprised of a plurality of concentric circles for reasons explained below in connection with Figs. 6 and 7. The circles are indicia of reference points which are spaced and arranged to define a coordinate grid on the panel 42. When the pattern piece P is inserted in the envelope 30, the pattern is effectively overlaid on the imaginary grid established by the reference marks 46, and each point of the pattern piece is brought into registration with the grid. Since the positions of the reference marks 46 are known, and preferably are 13 pre-established to have a regular spacing corresponding to the coordinate grid, each position of the pattern piece periphery is known with respect to the coordinate grid. Thus, any distortion that arises in the scanning operation can be corrected in accordance with the differences between the known grid and the distortions of the grid apparent in the image data.

Fig. 4 is a graphic representation of the image data that is transmitted to the data processor 14 from the scanner 12. The image data at this point of the process is uncorrected for mechanical, electrical and optical distortion that arises in the course of the scanning operation. For example, the image in Fig. 4 is elongated in the lateral or Ydirection and is compressed in the vertical or Xdirection. For purposes of illustration both distortions are greatly exaggerated so that the reference marks 461 resemble ellipses rather than circles, and the pattern piece periphery P' has a more square shape. In reality the distortions in the X- and Y directions are not so large, and the circles are close approximations of circles. Additionally, the distortions are not likely to be linear or uniform, and the distortions in one region of the image will differ from those in another region.

14 Fig. 4 illustrates the coordinate grid that is defined by the reference marks 461 in distorted form. On the other hand Fig. 3 illustrates the undistorted reference marks and correspondingly defines the reference grid in undistorted form. Such a grid is not actually reduced to a visual form either in the image data or on the envelope of Fig. 3. Hence no portion of the image of the pattern piece is obstructed by either the grid or the reference marks since the marks are located along the periphery of the image. Accordingly, important contours or reference points on the edge or within the pattern are not obstructed as in the prior art systems.

is The data processor 14 in Fig. 1 is utilized to transform the uncorrected image data of the pattern piece P' represented in Fig. 4 to corrected image data representing the pattern piece P as shown in Fig. 3. The transformation is carried out by a software program within the processor and relies primarily upon well- known equations or transforms for converting data from one coordinate system to another. Such transforms are discussed more explicitly in the reference entitled Digital Image Processing (cited above) in Chapter 5 entitled Image Restoration. In an elementary transform, the transforms in each axis are linear. Since the distortions produced in a scanning operation are non linear or not evenly distributed, it is advisable to divide the image into regions and establish a separate transform for each region. In one embodiment of the invention the regions are divided into triangles as shown in Fig. 4 with apexes that are coincident with the intersections of the abscissas and ordinates of the reference marks 46.

Each point along the pattern periphery P' is then associated with a particular region and the coordinate transform for that region is applied to each point to establish the correct location for that point in an undistorted reference grid. In other words, the distorted data is corrected to eliminate the distortion in accordance with the uncorrected data defining the reference marks and the correct data defining the known positions of the reference marks.

Fig. 5 illustrates the overall method for scanning and generating corrected image data. The operations performed in the data processor 14 began at 54.

The first step of the method as indicated at 50 is to scan the image and the reference marks in the scanner 12 with the pattern piece P inserted in 16 the envelope 30. By using the envelope the pattern piece P and the panel 42 containing the reference marks are overlaid in fixed registration with one another and remain in fixed registration due to friction between the panels 40, 42 and the pattern piece. The pattern piece P and the envelope thus pass together between the feed rollers 32, 34 of the scanner 12 as shown in Fig. 2.

The scanner 12 in conventional fashion scans the envelope and pattern piece in a raster and generates raster data which is processed within the scanner to normalize the data and make synchronization corrections as described above. Such processing is indicated at 52 in Fig. 5 and is is carried out within the scanner. The result of such processing is image data which is uncorrected for distortion that arises during the scanning process.

The data from the scanner is then supplied to the data processor 14 where in one embodiment the raster data is converted to vector data as shown at 54. In other words, the raster data being essentially point data is converted to vectors which define the closed contours of the pattern piece P as well as the concentric circles of the reference marks 46 as polygons.

17 After the raster data has been converted to vector data, the processor 14 searches the vector data to identify the data which corresponds to the circles of the reference marks 46 as indicated at 56.

Discrimination between the reference marks and the other data defining the pattern image is important because the reference marks establish the amount, location and degree of distortion that occurred during the scanning operation and become the basis for correcting the distortion of the image data.

In the preferred embodiment of the present invention the reference marks are formed by the plurality of concentric circles, as indicated in Fig. 3, because a unique data processing technique has is been discovered for discriminating between data defining circles and other closed patterns in the uncorrected data from the scanner 12. It is a wellknown axiom that a circle is the most efficient geometric configuration for enclosing a given area.

In other words, the circumference of a circle is the smallest peripheral dimension that envelopes a given area. Utilizing this axiom it can be shown with a reasonably high degree of certainty that if the expression C2/4A, wherein C equals the length of the periphery of a closed pattern and A equals the area of the closed pattern, is equal to r or at least less 18 than 3.2, the pattern is a circle and not another closed pattern such as the pattern piece P.

Consequently, by processing vector data for each of the closed patterns detected in the data from the scanner 12, the circular reference marks can be identified in the scanner data and can be differentiated from the other data which defines the contours of the pattern piece P. The actual calculations performed to differentiate the circular reference marks from the other data can be understood more clearly from Figs. 6 and 7.

Fig. 6 illustrates a closed pattern or polygon whose periphery is made up of a plurality of vectors defined by the data converted at 54 in Fig.

5. Each segment of the periphery of the polygon is a single vector and the length of such a vector can be readily established from the coordinates at each end of the vector.

Furthermore, with the coordinates of each vector known, the polygon can be divided into a plurality of triangles, each having a common apex designated 0. The area of the polygon is equal to the sum of the areas of the several triangles, and the area of each triangle can be determined from the generic expression Ai and the coordinates of each corner of the triangle as given in Fig. 7. The areas 19 of the individual triangles are then added to determine the total area of the polygon and the length of each vector is added to obtain the periphery of the polygon. The calculated area and periphery of the polygon are then substituted in the expression C2/4A to determine whether the polygon is: a circle or not in accordance with the criteria set forth above.

Once the circles of the reference marks have been delineated in the image data, the processor 14 identifies the reference points of the circle as indicated at 58. The reference points are the actual centers of the concentric circles and correspondingly define the reference grid. For example, although the reference marks 46 in Fig. 3 are only located along the periphery of the envelope 30, they identify not only actual coordinates of a reference grid, but also all other coordinates of the grid. Thus the reference grid is fully defined by the peripheral reference marks 46.

To accurately determine the coordinates of the reference points or centers of the circles of the reference marks 46, the coordinates of each center Xcr Yc are calculated from the expressions shown in Fig. 7, the parameters of which are illustrated in Fig. 6. It will be recognized that the expressions for XC and YC are actually well-known calculations for first establishing the centroids of each triangle and then determining from the centroids of the triangles, the centroid or center of the polygon.

Since the polygon is in fact a circle, the coordinates of the centroid are also the coordinates of the center of the circle and the reference point for a reference mark 46.

While types of reference marks other than circles may be used, the concentric circles are advantageous because 1) they distinguish the reference marks 46 from single circles 48 forming part of the pattern piece, and 2) they allow the reference points to be determined with great accuracy. Since CCD cameras actually detect transitions between light and dark areas of an image, each circle of the referencemark 46 produces two sets of data, one representing the inner edge of the line defining the circle and the other representing the outer edge of the line'defining the circle. Thus, the four concentric circles of each reference mark 46 provide data for establishing eight centers or reference points, which in the ideal situation should all be the same. However, due to finite resolution of the cameras, line thickness variations and other factors, some deviation of the coordinates 21 or the centers can be expected. Taking an average value of the coordinates for all eight sets of data minimizes the effects of these errors and provides a highly accurate set of coordinates defining the centers or reference points of the reference marks 46.

Once the reference points of the marks 46 have been established, the grid coordinates anywhere within the reference marks are likewise determined.

Such reference points establish the actual location of each intersection of the triangular mesh pattern shown in Fig. 4. From the actual locations of the intersections and the known correct location of the intersections in the reference grid, a coordinate transform is established by the data processor at 60 for each triangular region. A plurality of transforms is thus established for the plurality of regions within the coordinate grid because the distortion in one region may be different from the distortions in other regions. once such transforms are established, then each point of the data defining the pattern piece P' in Fig. 4 can be spatially mapped into the reference grid or coordinate system to produce data that is corrected for distortion that arose in connection with the scanning process.

22 Accordingly, the data processor 14 examines the uncorrected data produced by the scanner 12 and initially determines at branch 62 whether the data represents a reference mark or data for the pattern piece P'. If the data is a reference point, the program branches to another branch 70 and removes all output reference data at 72. If the data is not a reference mark and therefore represents a vector point of the polygon defining the pattern piece, the program advances to 64 where the point under discussion is examined and associated with a particular region or triangle of the coordinate grid. Once the association is made, the vector point is spatially mapped into the reference grid by the is transform corresponding to the identified triangular region at 66. At this point, therefore, the data defining the vector point has been transformed from uncorrected data to corrected data, and the data is then stored in memory at 68. The program then advances to branch 70 to determine if more points are to be processed. If there are more points the program returns to branch 62 and the process is repeated. When the last data point has been processed, the processor 14 outputs image data that defines the periphery of pattern piece P without distortion at 74.

23 Thus, the invention as described above allows a conventional scanner to be used to reduce images of pattern pieces and other images to data which has been corrected to remove distortions that arise from the scanning process.

While the present invention has been described in a preferred embodiment it should be understood that numerous modifications and substitutions can be made without departing from the spirit of the invention. For example, although the image-bearing member described in the invention is a pattern piece P, the invention can be employed for reducing other types of images, both visual and otherwise as long as the images can be detected by the scanner. The scanner 12 utilizes a feed mechanism for moving the image bearing carrier through the scanner during a scanning operation; however, flatbed scanners which hold the carrier stationary during a scanning operation can also be employed. The transforms for spatially mapping the data from one coordinate system to another may be either linear or non-linear, and the reference grid may be rectilinear, polar or other types of grids as long as an appropriate transform is utilized. The envelope bearing the reference marks can take a number of different forms.For example, the 24 reference marks may be located on the transparent panel rather than the opaque panel if care is exercised in locating the pattern image so that the critical points are not covered up. Alternately, the processing of the uncorrected data may include subroutines for further analysis of the data in order.to separate the data representing the reference marks from the image data. Additionally, the invention can be employed with a simple overlay to which the image bearing carrier is secured without employing an envelope structure. Accordingly, the present invention has been described in several preferred embodiments by way of illustration rather than limitation.

Claims

1. A method of scanning an image carrier and producing image data corrected for distortion characterized by:

providing a planar member (40 or 42) with indicia (46) defining known reference points on the member, overlaying the planar member (40,42) and an image carrier (P) to place the indicia (46) in fixed registration with the image on the carrier, scanning the overlaid planar member (40,42) and image carrier (P) to produce data representing the image and indicia uncorrected for distortion arising from the scanning operation, and processing the uncorrected data to produce corrected data in accordance with the distortion of the known reference points in the uncorrected data.

2. A method of scanning and producing image data as defined in claim 1 characterized in that the step of processing includes establishing coordinate transforms (60) on the basis of the distortion of the known reference points in the uncorrected data.

26

3. A method of scanning and producing image data as defined in claim 1 characterized in that the step of processing further includes establishing a plurality of coordinate transforms (60) corresponding respectively to a plurality of regions of the image carrier (P), and then processing (62-64) the uncorrected data from the regions of the image by means of the respective coordinate transforms for the regions.

4. A method of scanning an image carrier and producing image data as defined in claim 1 characterized in that further steps include differentiating (62) the image data from the indicia data in the corrected data, and removing (72) the indicia data from the image data to produce the corrected data defining the image alone.

5. A method of scanning an image carrier and producing image data as defined in claim 4 characterized in that the indicia (46) on the planar member are circles.

27

6. A method of scanning an image carrier and producing image data as defined in claim 5 characterized in that the step of differentiating (60) establishes the data defining a pattern in the data to be indicia data when the expression C2/4A is less than a predetermined number, wherein C is the length of the periphery of the pattern and A is the area of the pattern.

7. A method of scanning an image carrier and producing image data as defined in claim 1 characterized in that the indicia (46) on the planar member are concentric circles.

8. A method of scanning an image carrier and producing image data as defined in claim 1 is characterized in that the indicia (46) are located along the periphery of the planar member.

28

9. Apparatus for scanning an image- bearing carrier and generating scanned image data corrected for distortion including image scanner (12) for scanning images on a carrier (P) and generating image data uncorrected for distortion arising from the scanning operation, a planar member (40 or 42) bearing precisely located indicia (46) distributed over the surface of the planar member and defining known reference points on the member whereby an image-bearing carrier (P) and the planar member (40,42) can be overlaid to register the image with respect to the indicia.(46) defining known reference points in a scanning operation, both the image and the indicia being included in the uncorrected data generated by the scanner (12) during the scanning operation, and a processor (14) connected with the scanner (12) to receive the uncorrected data of both the image and the indicia for transforming the uncorrected data of the image to image data corrected for distortion in accordance with the uncorrected data defining the indicia on the planar member (40,42) and correct data defined by the known positions of the indicia (46) on the planar member (40,42).

29

10. Apparatus for scanning and generating as defined in claim 9 characterized in that the processor (14) includes a program (60) for establishing coordinate transforms on the basis of the uncorrected and correct data defining the positions of the indicia on the planar member for converting the uncorrected data of the image to correct data of the image.

11. Apparatus for scanning and generating as defined in claim 10 characterized in that the processor includes a program (58) forming a reference grid based on the known reference points of the indicia and the program (60) establishing coordinate transforms establishes a plurality of transforms is corresponding respectively with a plurality of regions of the grid.

12. Apparatus for scanning and generating as defined in claim 11 characterized in that the image data from the scanner (12) defines data points of the image and the indicia, and the processor (14) further includes a program (64) correlating the data points of the image with corresponding regions of the grid in which the points are located.

13. Apparatus for scanning and generating as defined in claim 12 characterized in that the processor (14) includes a program (66) causing a data point of the image to be processed by the coordinate transform associated with the region of the grid in which the data point is located.

14. Apparatus for scanning and generating image data corrected for distortion as defined in claim 9 wherein the planar member (40 or 42) bearing the indicia (46) is one panel of a two panel envelope (30) whereby the image-bearing carrier can be positioned between the two panels of the envelope to overlay the indicia and the image.

15. Apparatus for scanning and generating as defined in claim 14 characterized in that one (40) of the panels of the two panel envelope (30) is transparent and the other (42) of the panels is opaque.

16. Apparatus for scanning and generating as defined in claim 15 characterized in that the indicia (46) defining known reference points are disposed on the opaque panel (42) of the envelope.

31

17. Apparatus for scanning and generating as defined in claim 9 characterized in that the indicia (46) on the planar member (40 or 42) include a circle.

18. Apparatus for scanning and generating as defined in claim 9 wherein the processor (14) further includes a program (62) for discriminating the data representing the indicia (46) from the data defining the image in the data from the scanner (12).

19. Apparatus for scanning and generating as defined in claim 9 characterized in that the indicia (46) on the planar member (40 or 42) are located near the periphery of the member to avoid overlap with the image on the carrier (P).

20. Apparatus for scanning an image bearing carrier and generating scanned image data corrected for distortion substantially as described herein.

21. Apparatus for scanning an image bearing carrier and generating scanned image data corrected for distortion 20. substantially as described with reference to the accompanying drawings.

22. A method of scanning an image carrier and 32 producing image data corrected for distortion substantially as described herein.

z

23. A method of scanning an image carrier and producing a image data corrected for distortion substantially as described herein with reference to the accompanying drawings.