id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
711	psImage parent vs subimage	eugene	David.Robbins@…	"some of the code, as well as the sdrs, are inconsistent on the issue of whether
an operation on an image refers to the subimage coordinates or the parent
coordinates.  this is particularly a problem when mixing subimages of subimages
or regions and subimages.  We (IfA) have decided that it makes sense for all
image operations to refer to the *parent* coordinates; thus actions are
independent of whether they operate on an image or subimage, they use the same
coordinates:

feature = psImageFindFeature (image);
region = psRegionForSquare(feature->x, feature->y, 50);
region = psRegionForImage(image, region);
subimage = psImageSubset(image, region);

result = psFeatureAnalysis(subimage, feature->x, feature->y);

I have made several fixes to functions which were needed by our tools in active
development (psphot, ppImage).  there are others which need to be fixed.  I have
modified (in rel10_ifa):

psImageSubset
psRegionForImage
psImageCountPixelMask

a variety of other functions likely will need to be adjusted:

psImageSet()
psImageGet()
psImageRow()
psImageCol()
psImageSlice()
psImageCut()
psImageTransform()
psImageFitPolynomial()  - coeffs should refer to the parent coords
psImageEvalPolynomial() - ditto
psImagePixelInterpolate()
psPixelsToMask()"	defect	closed	high		mathtypes	0.10.0	normal	fixed