You can convert the images to base64 using an ExcelScript, which you can call from a Power Automate flow, which can either return the base64 image to your Power App, or save the image to a SharePoint document library to view in your gallery.. It's not a simple task.. but not a super difficult one either.
This is actually part of the requirements for a project I am working on, which I have already developed the script to convert the worksheet into HTML, and the images into base64, which is transferred to the app, but I have not yet developed the formulas to utilize those images..
In ExcelScript you need to get the images from the worksheet's shapes... Keeping in mind that I am no Excel/JavaScript expert, here is an example from my script:
if (ws_obj.getShapes()) { // .....Check if Shapes Exist
var arr_temp = ws_obj.getShapes(); // ......Create Temporary Shapes Array
for (i = 0; i < arr_temp.length; i++) { // ......Process Shapes
var st_temp = arr_temp[i].getType(); // .......Get Temp Shape Type
if (st_temp == ExcelScript.ShapeType.image) // .......Check if Image
arr_shape.push(arr_temp[i]); // ........Add Shape to Array
}; // ......End Processing Shapes
}; // .....End Shapes Check
Later on, I do this to save the images to the 'HTML_SHEET' object I convert to a JSON string, and send back to the flow.
for (i = 0; i < arr_shape.length; i++) { // ......Process Image Shapes
var png = ExcelScript.PictureFormat.png; // .......Get PNG Format
var b64 = arr_shape[i].getImageAsBase64(png); // .......Get Image Base64 String
var obj = { // .......Create Image Object
NAME: "Image_" + (i + 1) + ".PNG", // ........File Name
BASE64: b64 // ........File Contents
}; // .......End Image Object
arr_image.push(obj); // .......Add to Array
tm_elapsed = Date.now() - tm_ScriptStart; // .......Get Elapsed Time
if (tm_elapsed > ms_minRemaining && ms_limit > 0) break; // .......Break Loop if Out of Time
}; // ......End Processing Image Shapes
My flow saves this to a multi-line text column I added to the file's document library. This actually happens automatically if a file hasn't already been processed.. I have another flow that checks the library for files that haven't been processed that calls this flow that runs the ExcelScript... but I digress..
My point is that all of this is possible. (but pretty complicated) Hopefully this will help get you towards what you're looking for. Sorry I haven't completed the final steps myself yet.. (Working on another part of the project)
