CSC320 Visual Computing Assignment 2

Announcements

Requirements

• We will be doing the StGeorge Assignment 2 but see the differences below...
• You should submit via the UTM webbased submit (above)
• You must get your code running on cslinux (or equivalently in 1158 under Linux).
• We did not cover the DoG (Difference of Gaussian) approximation to the LoG (Laplacian of Gaussian) in our lectures. The idea is simple, see page 15 and 16 of the StGeorge notes. You can simply compute the LoG by appropriate calls to VGaussianConvolveImage (see man page).

References

• More later

Questions and Answers

Question:

I can't access all the man pages for Vista in 1158 (or in cslinux)

Answer:

You can find the complete set of man pages for Version 2.1.6 of Vista here. This includes the VTutorial.

The complete set of Vista man pages is not yet available on cslinux. The Vista man pages currently available on cslinux are...(type man VBundle for example)...

VBundle.3 VFillImage.3 VNewString.3 VRGBImageToGray.3 VCalibrateCamera.3 VFlipImage.3 VNoiseImage.3 VRotateImage.3 VCamera.3 VForkImageDisplay.3 VNumber.3 VSameImage.3 VCameraCoord.3 VGaussianConvolveImage.3 VOffset.3 VScaleImage.3 VCameraError.3 VGetAttr.3 VOpenFile.3 VSegEdgesIntoLines.3 VCanny.3 VGetPixel.3 VOptFlowWLS.3 VSelectBand.3 VColormap.3 VIdentifyFiles.3 Voption.3 VSelectDestImage.3 VCombineBands.3 VImage.3 VPackData.3 VSetAttr.3 VConst.3 VImageFFT.3 VParseCommand.3 VSetBandInterp.3 VConvertImageCopy.3 VImageGradient.3 VParseFilterCmd.3 VSetErrorHandler.3 VConvertImageLinear.3 VImageMagnitude.3 VParseParamOptions.3 VSetProgramName.3 VConvertImageOpt.3 VImageOp.3 VParsePSDistance.3 VSetWarningHandler.3 VConvertImageRange.3 VImagePhase.3 VParsePSOptions.3 VTransposeImage.3 VConvolveImage.3 VImageStats.3 VPatternImage.3 Vtype.3 VConvolveImageSep.3 VImageToPS.3 Vpostscript.3 VWarning.3 VCopy.3 VImageView.3 VPrintOptions.3 VWriteEdges.3 VCopyBand.3 VImageWindowSize.3 VPrintParameters.3 VWriteFile.3 VCopyImage.3 VInsertAttr.3 VReadEdges.3 VWriteImages.3 VCreateImage.3 VInvertImage.3 VReadFile.3 VWriteObjects.3 VCropImage.3 VKernel.3 VReadImages.3 VWriteUbcIff.3 VDecodeAttrValue.3 VLinkImage.3 VReadObjects.3 VZeroCrossings.3 Vdictionary.3 VList.3 VReadPlain.3 VEdges.3 VLoadParameters.3 VReadPnm.3 v1to2.1 vcatbands.1 vflip.1 vlayout.1 vphase.1 vselect.1 vblur.1 vcomplex.1 vflow.1 vlink.1 vrgbtogray.1 vsynth.1 vcalsyn.1 vconvert.1 vgauss.1 vmag.1 vrotate.1 vtopgm.1 vcamcal.1 vconvolve.1 vgrad.1 vnegate.1 vscale.1 vtops.1 vcanny.1 vcrop.1 vinvert.1 vop.1 vsegedges.1 vtranspose.1 vcat.1 vfft.1 vistat.1 vpdc.1 vselbands.1 vzeroc.1

Question:

How can I access the Scissors paper?

Answer:

It is still under the week 4 lectures section of the 320 web page.

Question:

Here are some points that will make your life easier...

Answer:

• The routines used to display images expect VUByte images, so if you are using the provided routines to display an image, make sure you convert it to VUByte before display.
• An image of type VDouble has pixel values in the range 0-1
• An image of type VUByte has pixel values in the range 0-255
• The routines to convert between these representations (VConvertImageCopy) understand the above convention.
• At one point, you will be doing something like... i1=VGaussianConvolveImage(image, sigma_1); i2=VGaussianConvolveImage(image, sigma_2); laplacian=i1-i2; // See VImageOp zeroCrossingImage=VZeroCrossings(laplacian); You may want to take a look at the results. You can look at i1 and i2 (but remember to convert to VUByte first) You can't look at laplacian since the range of values is not 0-1. You will need to normalize the image somehow to display the laplacian. The same applies to zeroCrossing. If you want to see the zeroCrossing image, you can find the maximum pixel value in zeroCrossing and then divde the zeroCrossing image by this value. Now convert and display this. You may want to consider doing all of the above calculations on VDouble images.

Question:

Can I submit now?

Answer:

The submit link has changed. Please submit on the link at the top of this page.