I'm quite sure that many APEX developers have face problems when using images in interactive report. There is e.g. problem in filter and when export report you see escaped image HTML tag.
Recently I did saw Jeff Holoman's great post Using images in APEX Interactive Reports to solve partly this problem.
I have previously also struggle with this same problem. I explain here how I have workaround problem.
In this solution I have used column link and column value must be part of image name.
Just like Jeff Holoman's post my example column value is Yes or No. I use images chk_Yes.png and chk_No.png in report.
I did uploaded those images to workspace images. Then interactive report from query
SELECT product_id ,
DECODE(product_avail,'Y','Yes','N','No',NULL) AS product_avail
WHERE product_name IS NOT NULL
Edit product_avail column and enter to Link Text
</a><img src="#WORKSPACE_IMAGES#chk_#PRODUCT_AVAIL#.png" alt="" /><a href="#" class="hideMe508">
Change Target to URL and URL enter #
Using this method you filter by real column value and you get value to e.g. CSV export instead image HTML tag.
See working example.