Is Resize off by a factor of 2?

[M-M-T-T]

I assume that the NewWidth and NewHeight arguments to QRCodegenResizePicture are intended to be in points. If so, I am seeing results that suggest they are off by a factor of 2.

TestImage100 is an ActiveX image control in MS Word (on Win 10) that is sized to 100x100 points (roughly 1/2 inch on each side) in MS Word.

Running this code:

    TestImage100.PictureAlignment = 2 'fmPictureAlignmentCenter
    TestImage100.PictureSizeMode = 0 'fmPictureSizeModeClip
    TestImage100.PictureTiling = False
    
    Debug.Print "Form's width=" & CStr(TestImage100.width)
    Set testImage = QRCodegenBarcode(TestText2.Text, SquareModules:=(TestCheckBox1.Value = True), ModuleSize:=10)
    Debug.Print "QRCode image's width=" & CStr(testImage.width)
    Debug.Print "...Inserting QRCode image into form"
    Set TestImage100.Picture = testImage
    Debug.Print "Form's width=" & CStr(TestImage100.width)
    Debug.Print "Form's picture's width=" & CStr(TestImage100.Picture.width)
    Debug.Print "Resizing QRCode to 100x100"
    Set resizedTestImage = QRCodegenResizePicture(testImage, 100, 100)
    Debug.Print "Resized QRCode's width=" & CStr(resizedTestImage.width)
    
    Debug.Print "...Inserting resized QRCode image into form"
    Set TestImage100.Picture = resizedTestImage
    Debug.Print "Form's width=" & CStr(TestImage100.width)
    Debug.Print "Form's picture's width=" & CStr(TestImage100.Picture.width)

produces this output:

Form's width=100.8
QRCode image's width=3122
...Inserting QRCode image into form
Form's width=100.8
Form's picture's width=3122
Resizing QRCode to 100x100
Resized QRCode's width=1764
...Inserting resized QRCode image into form
Form's width=100.8
Form's picture's width=1764

Apparently, the StdPicture object's width and height are in some different unit than points. (The screen is 14" 1920x1080, ie 16x9 12.3"x6.9" so 156 pixels/inch)

After resizing the image to 100x100 (NewHeightxNewWidth), the QR image fills approximately 50x50 points as shown here. The yellow is the background of the image control object (whose height & width is approximately 100 points)

If I resize to 200x200, it fills the 100x100 pixel image.

[wqweto]

JFYI, QRCodegenBarcode returns a QR Code rendered with vectors as a Windows Metafile (.wmf) based StdPicture while QRCodegenResizePicture takes a bitmap or a vector picture and returns a bitmap bases StdPicture and it uses pixels for desired output dimensions.

Also, StdPicture's Width and Height properties are always in HIMETRIC units so converting these back and forth to pixels will not be exact (unless using floating point values for Width and Height properties).

You can take a look at HM2Pix procedure in module's source code how the conversion is done. A simpler version of this procedure would be

Public Function HM2Pix(ByVal Value As Double) As Long
    HM2Pix = Int(Value * 1440 / 2540 / Screen.TwipsPerPixelX + 0.5)
End Function

As you can see size in pixels from HIMETRIC units depends on screen DPI so 1764 in HIMETRIC converts to 100 pixels when your screen scaling is set to 150%. On my machine 1764 in HIMETRIC units converts to 83 pixels as I'm using 125% scaling.