Photo Mosaic Customization Code

I'm in need someone who can modify existing photo mosaic creation software to fit my specific needs. I don't have any specific program in mind. Hopefully there's something already open source code out there to work with. Altogether, I do NOT have any complicated requirements. I am a woodworker and I need to slightly modify a photo mosaic program to help make my pieces. I want to design and make physical art pieces that could use the help of photo mosaic software. I want to modify already available API photo mosaic software so that I input hundreds/a few thousand of images of the end grain of square wood blocks, which I create, which will vary in grain style, direction and color, and arrange those images to construct a final image, similar to the way photo mosaic software does (pic 1 and 2). I've uploaded two pictures to discuss what photo mosaic software does. Some software modifies the original input images' color values to produce something like in the second picture. Since I'm using physical wood blocks whose appearance I can't vary after the images are taken, I will be producing images something closer to the first picture I uploaded. The art pieces produced will be more impressionistic of the target photo rather than a realistic representation. I've uploaded a picture of one of my previous art pieces (3) where I've heat treated the different blocks of wood to give the varying color effect. The first piece I'll be designing with this new mosaic software would be with similar looking blocks of wood, and the target picture will be a high contrast picture of horses running (4). To start out the wood blocks will be simple, but I will be adding color staining techniques to the wood blocks in the future as I try to create more complex images. The resolution of the final pieces will depend on how small the wood blocks are and how large the final piece is. The wood blocks will be 20mm on each side and the final images will always be large enough to give good resolution, say 1m tall by 2m wide. All blocks will be the same size. The clients who will want this art have horses so this particular images will be a popular one to recreate. I need the software to only output a couple things. First is what the final picture will look like given the input pictures I've given it. I don't want to spend many hours arranging a couple thousand wood blocks only to find I don't like the image. And second, is in what order the blocks need to be arranged. I will need it to give me the the individual image names based on the order the final pieces blocks are arranged. Also, the software will need to be able to rotate the images within themselves in order to make the target image more accurate. I have a little programming experience so I am completely comfortable with command line interface. The interface does not have to look good. I work on a windows based computer but I can purchase another computer to run the software if necessary. I do not have performance requirements for the software. Sorry, I'm not sure what language one will need to be proficient in. I've taken the brief survey to build this advertisement and it's chosen these next two stipulations. - Customizable Mosaic Shape: Flexible parameters allowing for various shapes should be written into the code. - Custom Image Mosaic Tiles: The software needs to accept and accurately utilize input images of my selection. In-depth understanding of software modification and image manipulation is paramount for success. Experience working with photo mosaic software would be a definite advantage. Don't hesitate to reach out if you believe this is within your scope of expertise.