PureBasic Forum

typedef struct CvMemStorage
{
    int signature;
    CvMemBlock* bottom;           /* First allocated block.                   */
    CvMemBlock* top;              /* Current memory block - top of the stack. */
    struct  CvMemStorage* parent; /* We get new blocks from parent as needed. */
    int block_size;               /* Block size.                              */
    int free_space;               /* Remaining free space in current block.   */
}
CvMemStorage;

cvFindContours(*image, *storage, *first_contour, header_size, mode, method, x, y)

C: int cvFindContours(CvArr* image, CvMemStorage* storage, CvSeq** first_contour, int header_size=sizeof(CvContour), int mode=CV_RETR_LIST, int method=CV_CHAIN_APPROX_SIMPLE, CvPoint offset=cvPoint(0,0) )

IncludeFile "includes/cv_functions.pbi"

; C declaration:
;================
;
; typedef struct CvPoint2D32f
; {
;     float x;
;     float y;
; }
; CvPoint2D32f;
;
; typedef struct CvSize2D32f
; {
;     float width;
;     float height;
; }
; CvSize2D32f;
;
; typedef struct CvBox2D
; {
;     CvPoint2D32f center;  /* Center of the box.                          */
;     CvSize2D32f  size;    /* Box width and length.                       */
;     float angle;          /* Angle between the horizontal axis           */
;                           /* And the first side (i.e. length) in degrees */
; }
; CvBox2D;
;
; /* Finds minimum area rotated rectangle bounding a set of points */
;CvBox2D cvMinAreaRect2(const CvArr* points, CvMemStorage* storage=NULL )
;
;Parameters
;points – Input vector of 2D points, stored in:
;– CvSeq* or CvMat* (C interface)
;==============================================================================

Structure CvPoint2D32f  Align #PB_Structure_AlignC
    x.f
    y.f
EndStructure

Structure CvSize2D32f Align #PB_Structure_AlignC
    width.f;
    height.f;
EndStructure

Structure CvBox2D Align #PB_Structure_AlignC
    center.CvPoint2D32f   ; Center of the box. 
    size.CvSize2D32f      ; Box width and length.
    angle.float           ; Angle between the horizontal axis And the first side (i.e. length) in degrees
EndStructure

ImportC "opencv_imgproc247.lib"
  cvMinAreaRect2(*CvArr, *CvMemStorage=#Null)
EndImport

Global  MARect.CvBox2D, *mems.CvMemStorage
 
Debug("Mat Start filling")
*kernel = cvCreateMat(250, 250, CV_MAKETYPE(#CV_8U, 3))
cvSet(*kernel, 0, 0, 0, 0, #Null)

; Draw rectangle
For i=0 To 99
  For j=0 To 249
    cvSet2D(*kernel, i, j, 0, 0, 0, 0)
  Next j
Next i

For i=100 To 149
  For j=0 To 75
    cvSet2D(*kernel, i, j, 0, 0, 0, 0)
  Next j
  For j=76 To 175
    cvSet2D(*kernel, i, j, 1, 0, 0, 0)
  Next j     
  For j=176 To 249
    cvSet2D(*kernel, i, j, 0, 0, 0, 0)
  Next       
Next i   

For i=150 To 249
  For j=0 To 249
    cvSet2D(*kernel, i, j, 0, 0, 0, 0)
  Next j
Next i     
Debug("Mat filled")

*rect = @MARect
*rect = cvMinAreaRect2(*kernel,*mems)
Debug("Center: X="+StrF(MARect\center\x)+" Y="+StrF(MARect\center\y)+", Angle="+StrF(MARect\angle))
Debug("Width="+StrF(MARect\size\width)+", Height="+StrF(MARect\size\height)) 

cvReleaseMat(@*kernel)

; OpenCV
; Image filtration on the minimum area of a contour
; (removal of small elements of the image or noise)
; Based on JHPJHP code cv_contours.pb
;
; The filter On/Off by #FilterOn value
;
; AAT
;==================================================

IncludeFile "includes/cv_functions.pbi"

#CV_WINDOW_NAME = "Contour Area Filter"
#FilterOn = #True           ; Filter On = #True, Off = #False
#FilterValue = 35           ; minimal area of the visible contour

ImportC "opencv_imgproc247.lib"
  cvContourArea.d(*contour, start_index.i, end_index.i, oriented.i) 
EndImport 

ImageFolder.s = Space(#MAX_PATH)
SHGetFolderPath_(#Null, #CSIDL_MYPICTURES, 0, 0, ImageFolder)
PathAddBackslash_(ImageFolder)
Pattern.s = "All Images (*.*)|*.bmp;*.dib;*.jpeg;*.jpg;*.jpe;*.png;*.tiff;*.tif|Windows Bitmaps (*.bmp)|*.bmp;*.dib|JPEG Files (*.jpg)|*.jpeg;*.jpg;*.jpe|Portable Network Graphics (*.png)|*.png|TIFF Files (*.tiff)|*.tiff;*.tif"
ImageFile.s = OpenFileRequester("Please choose an image file", ImageFolder, Pattern, 0)

If ImageFile
  *image.IplImage
  *gray.IplImage
  *contour.IplImage
  carea.d   
  cvNamedWindow(#CV_WINDOW_NAME, #CV_WINDOW_NORMAL)
  *image = cvLoadImage(ImageFile, #CV_LOAD_IMAGE_ANYDEPTH | #CV_LOAD_IMAGE_ANYCOLOR)
  cvResizeWindow(#CV_WINDOW_NAME, *image\width, *image\height)
  cvMoveWindow(#CV_WINDOW_NAME, 20, 20)
  *storage.CvMemStorage
;  *contours.CvContour
  *contours.CvSeq                            ; same result as *contours.CvContour
  *storage = cvCreateMemStorage(0)
  *gray = cvCreateImage(*image\width, *image\height, #IPL_DEPTH_8U, 1)
  cvCvtColor(*image, *gray, #CV_BGR2GRAY, 1)
  cvThreshold(*gray, *gray, 64, 255, #CV_THRESH_BINARY)
  nContours = cvFindContours(*gray, *storage, @*contours, SizeOf(CvContour), #CV_RETR_LIST, #CV_CHAIN_APPROX_SIMPLE, 0, 0)
  If nContours
    *contour = cvCreateImage(*gray\width, *gray\height, #IPL_DEPTH_8U, 3)   
    cvSet(*contour, 5, 5, 5, 0, #Null)
;    Debug("#Counturs="+Str(nContours))
    For rtnCount = 1 To nContours           
      carea = cvContourArea(*contours, 0, $3fffffff, 0)
;      Debug("Contour Area="+StrD(carea))   
      If #FilterOn = #True
        If carea => #FilterValue
          cvDrawContours(*contour, *contours, 255, 155, 0, 0, 155, 255, 0, 0, -1, 1, #CV_AA, 0, 0)                                     
        EndIf
      Else
        cvDrawContours(*contour, *contours, 0, 155, 255, 0, 0, 255, 255, 0, -1, 1, #CV_AA, 0, 0)         
      EndIf     
      *contours = *contours\h_next
    Next

    Repeat
      If *contour
        cvShowImage(#CV_WINDOW_NAME, *contour)
        keyPressed = cvWaitKey(0)
      EndIf
    Until keyPressed = 27
   
    cvDestroyWindow(#CV_WINDOW_NAME)
    cvClearMemStorage(*storage)
    cvReleaseImage(@*contour)
    cvReleaseImage(@*gray)
    cvReleaseImage(@*image)
  EndIf
EndIf