How to avoid to measure a Cell who hold an image ?

In a project, I display the contents of a SQLite data base.

At load time, I have a Method (or is it a Function ?) who compute the Columns (one cell / one Column at a time) width (depending on the text size, font, etc.). This works fine, but…

In some of the sqlite db files, one or many images can be embedded. And the trouble is starting. For unknow reason, the routine takes time (3 to 5 seconds) when one image is embedded in the sqlite file (TABLE). Probably the length of the image…

I know this is the faultive code because I added a Return in the code first line and the delay disappears…

So, I add the code below before the code who gets the string (CellStr) width and this skips PNG images.

But I have no idea on how (it may be simple) to exclude other kinds of images (JPEG, TIFF, etc.)

CellStr = LB.Cell(RowIdx,ColIdx) If InStrB(CellStr,"PNG") = 0 Then

Must I add as many times as image formats (InStrB(CellStr,"<IMG_KIND>") = 0) the part to exclude each image kind ?
(JFIF and JPEG foe JPEG images… etc.)