why the accuracy is very low when i use my own picture

[xzshen]

I have a question, I use your source code to build a project on vs2013 of my computer, and when I enter a handwritten digital picture into it, the recognized numbers are wrong.
is there any any requirements for image input?
I used this code to replace the original code
READ_MNIST_DATA("F:/FPGA_CNN/minst/test_images/1_00002.jpg", MNIST_IMG, -1.0f, 1.0f, 1);
is there any wrong?

[changwoolee]

Hello, xzshen.

As I tested the few different handwritten picture with Windows app, the results were not so accurate although the accuracy from the test with MNIST test data (t10k-images-idx3-ubyte and t10k-labels-idx1-ubyte) was higher than 98%. The program can't catch my handwritten digits accurately so I resized and correct the tone and brightness of the picture on Photoshop. After then, it works not bad.

I think it's because of trained weights. I'll let you know if I fix the bug.

Also, did you add the code for reading the .jpg file in READ_MNIST_DATA()? The original code is for mnist datasets, not .jpg files.
If you did, the problem might be above, and if you didn't insert the code, please try it.

Thanks for your question.
Chang-woo Lee