Possibly. One common issue after data recovery is that files are misidentified and given the wrong extension. Before trying converters, make a copy of a file and change the extension back to what it originally was, such as .jpg or your camera’s raw format, then try opening it again. Recovery software can mislabel files.

If the files truly are BMPs, partial repair may be possible because BMP uses little or no compression, so any intact data may still translate into visible pixels. JPEG and other heavily compressed formats are harder to repair because the data depends much more on other missing parts of the file.

If the photos are important, stop experimenting on the originals and work only on copies. At that point, your best option may be a knowledgeable data-recovery specialist, especially if the files have real value. Online converters usually won’t help if the underlying file data is damaged or the file type has simply been labeled incorrectly.