All of the GPR files for 3D7 and Dd2 are missing the normal Headers from a GenePix .gpr file.
This means that the first 29 lines of a normal GPR file are absent.
These usually look something like this:

ATF	1
27	43
Type=GenePix Results 1.4	
DateTime=2004/01/21 13:03:52	
Settings=C:\Filelocation\file.gps	
GalFile=C:\Filelocation\file.gal.txt	
Scanner=GenePix 4000B [88593]	
Comment=	
PixelSize=10	
"ImageName=635	532"	
"FileName=C:\Filelocation\file_635.tif	C:\Filelocation\file_532.tif"	
"PMTVolts=610	530"	
"ScanPower=100	100"	
FocusPosition=0	
NormalizationFactor:RatioOfMedians=1.19836	
NormalizationFactor:RatioOfMeans=1.20461	
NormalizationFactor:MedianOfRatios=1.22357	
NormalizationFactor:MeanOfRatios=1.21427	
NormalizationFactor:RegressionRatio=1.22495	
JpegImage=C:\Filelocation\file.jpg	
RatioFormulation=W1/W2 (635/532)	
Barcode=	
ImageOrigin=980, 19870	
JpegOrigin=980, 19870	
Creator=GenePix Pro 3.0.6.73	
Temperature=32.34	
"LaserPower=3.4	3.62"	
"LaserOnTime=50408	50454"	
Supplier=	

Therefore, to open up in GenePix you will need to add these lines, otherwise not.