DrawImage
==================

.. js:function:: MNIST.DrawImage() 

ソース
^^^^^^

.. code-block:: js

        DrawImage() {
            var image_data = this.ctx.getImageData(0, 0, this.canvas.width, this.canvas.height);
            var data = image_data.data;
            var length = data.length;
    
            if (length != 4 * this.imgW * this.imgH) {
                console.log("length(%d) != 4 * ImgW(%d) * ImgH(%d) : %dx%d", length, this.imgW, this.imgH, this.canvas.width, this.canvas.height);
                return;
            }
    
            var wh = this.imgW * this.imgH;
    
            for (var i = 0; i < wh; i++) {
                var k = 4 * i;
                var c = 255 - this.trainingDataImage[wh * this.imgIdx + i];
    
                data[k] = c;
                data[k + 1] = c;
                data[k + 2] = c;
                data[k + 3] = 255;
            }
    
            this.ctx.putImageData(image_data, 0, 0);
    
            this.imgIdx++;
            if (this.imgIdx < this.trainingImgCnt) {
    
                setTimeout(this.DrawImage.bind(this), 1);
            }
        }