Experimental analysis of the quantitative ultrasonographic findings in maxillo-facial soft tissue structures

纹理分析的新方法是基于一种直觉，即人类视觉系统的重要纹理信息包含在强度的局部极值的相对频率中。该过程的主要测量是确定沿一维扫描方向的局部灰度最大值和最小值的数量。灰度值首先通过平滑处理发送，该平滑处理消除了小幅度的反转，从而仅保留了主要极值。平滑算法是熟悉的模拟机械过程称为齿轮间隙的数字等效，它最初被描述为字符识别的预处理方法。模拟组织幻象、正常腮腺、颌下腺、涎腺炎和唾液腺肿瘤的超声图像。这些图像经过扫描和数字化处理。在数字化图像中，用Max-Mm测量法对所选ROI进行一维分析。二维扩展测量了ROI中的max-mm特征。结果表明，阈值越大，检测到的极值越少，当阈值超过图像的像素密度范围时，没有检测到极值。每张图像都会产生一个特征曲线，可以用来识别纹理。在模体的基材中，同一ROI的不同密度图像产生的曲线略有不同。显然，ROT的面积越大，特征方差越小，分类结果越准确。

The new measure for texture analysis is based on the intuition that the important texture information for the human visual system is contained in the relative frequency of local extremas in intensity. The principal measurement in this process is the determination of the number of local gray level maximum and minimum along a one-dimensional scan direction. The gray level values are first sent through a smoothing process which eliminates reversals of small amplitude, thereby retaining only the principal extrema. The smoothing algorithm is the digital equivalent of the familiar analog mechanical process known as gear backlash and it was originally described as a preprocessing method for character recognition.The ultrasonographic images of the tissue-mimicking phantom, normal parotid and submandibular glands, sialadenitis and salivary gland tumors were used. The images were scanned, digitized. In the digitized images, the selected ROI was analysed with the Max-Mm Measure in one dimension. The two-dimensional extension measured the max-mm features in the ROI.As the results, the threshold was increased, fewer extrema were detected and when the threshold exceeded the pixel density range of the image, no extrema were detected. Each image produced a characteristic curve which can be used to identify the texture. Each different density image of the same ROI in the base-material of the phantom produced a slightly different curve. Obviously, a larger size region of the ROT would give less variance in the features and more accurate classification results.