运算符的特征

博客介绍了操作的几个关键概念,包括优先级、结合性、操作数以及含义,这些都是信息技术领域中理解操作的重要方面。

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优先级

结合性

操作数

含义

function robustFormulaRecognizer() % 创建主窗口 fig = figure('Name', '鲁棒公式识别系统', 'NumberTitle', 'off', ... 'Position', [100, 100, 1200, 800], 'MenuBar', 'none', ... 'Color', [0.95 0.95 0.95]); % 创建UI控件 uicontrol('Style', 'pushbutton', 'String', '上传图像', ... 'Position', [30, 750, 100, 30], 'Callback', @uploadImage, ... 'FontSize', 11, 'BackgroundColor', [0.3 0.6 0.9], 'ForegroundColor', 'white'); uicontrol('Style', 'pushbutton', 'String', '识别公式', ... 'Position', [150, 750, 100, 30], 'Callback', @recognizeFormula, ... 'FontSize', 11, 'BackgroundColor', [0.1 0.7 0.3], 'ForegroundColor', 'white'); uicontrol('Style', 'pushbutton', 'String', '清除结果', ... 'Position', [270, 750, 100, 30], 'Callback', @clearResults, ... 'FontSize', 11, 'BackgroundColor', [0.9 0.5 0.1], 'ForegroundColor', 'white'); % 创建图像显示区域 ax_original = axes('Parent', fig, 'Position', [0.05, 0.5, 0.4, 0.35]); title(ax_original, '原始图像'); axis(ax_original, 'off'); ax_processed = axes('Parent', fig, 'Position', [0.55, 0.5, 0.4, 0.35]); title(ax_processed, '处理图像'); axis(ax_processed, 'off'); ax_equal = axes('Parent', fig, 'Position', [0.05, 0.1, 0.4, 0.35]); title(ax_equal, '等号检测'); axis(ax_equal, 'off'); % 创建结果展示区域 result_panel = uipanel('Title', '识别结果', 'FontSize', 12, ... 'BackgroundColor', 'white', 'Position', [0.55, 0.1, 0.4, 0.35]); uicontrol('Parent', result_panel, 'Style', 'text', 'String', '识别公式:', ... 'Position', [20, 200, 80, 20], 'FontSize', 11, 'HorizontalAlignment', 'left'); formula_text = uicontrol('Parent', result_panel, 'Style', 'text', 'String', '', ... 'Position', [110, 200, 300, 20], 'FontSize', 11, 'HorizontalAlignment', 'left', ... 'BackgroundColor', 'white'); uicontrol('Parent', result_panel, 'Style', 'text', 'String', '计算结果:', ... 'Position', [20, 170, 80, 20], 'FontSize', 11, 'HorizontalAlignment', 'left'); calc_text = uicontrol('Parent', result_panel, 'Style', 'text', 'String', '', ... 'Position', [110, 170, 300, 20], 'FontSize', 11, 'HorizontalAlignment', 'left', ... 'BackgroundColor', 'white'); uicontrol('Parent', result_panel, 'Style', 'text', 'String', '用户答案:', ... 'Position', [20, 140, 80, 20], 'FontSize', 11, 'HorizontalAlignment', 'left'); answer_text = uicontrol('Parent', result_panel, 'Style', 'text', 'String', '', ... 'Position', [110, 140, 300, 20], 'FontSize', 11, 'HorizontalAlignment', 'left', ... 'BackgroundColor', 'white'); uicontrol('Parent', result_panel, 'Style', 'text', 'String', '验证结果:', ... 'Position', [20, 110, 80, 20], 'FontSize', 11, 'HorizontalAlignment', 'left'); result_text = uicontrol('Parent', result_panel, 'Style', 'text', 'String', '', ... 'Position', [110, 110, 300, 20], 'FontSize', 11, 'HorizontalAlignment', 'left', ... 'BackgroundColor', 'white'); % 等号检测日志 equal_log = uicontrol('Parent', result_panel, 'Style', 'listbox', ... 'String', {}, 'Position', [20, 30, 360, 70], 'FontSize', 10, ... 'BackgroundColor', 'white'); % 存储GUI句柄 handles = struct(); handles.ax_original = ax_original; handles.ax_processed = ax_processed; handles.ax_equal = ax_equal; handles.formula_text = formula_text; handles.calc_text = calc_text; handles.answer_text = answer_text; handles.result_text = result_text; handles.equal_log = equal_log; handles.current_image = []; handles.binary_image = []; handles.region_stats = []; handles.region_bboxes = []; handles.equal_sign_index = []; handles.ocr_results = []; guidata(fig, handles); % ======================== 回调函数 ======================== function uploadImage(~, ~) [filename, pathname] = uigetfile({'*.jpg;*.png;*.bmp', '图像文件 (*.jpg, *.png, *.bmp)'}, ... '选择公式图像'); if isequal(filename, 0) return; end img_path = fullfile(pathname, filename); img = imread(img_path); handles = guidata(fig); handles.current_image = img; % 显示原始图像 axes(handles.ax_original); imshow(img); title('原始图像'); % 预处理图像 gray_img = im2gray(img); % 图像锐化 - 增强边缘 sharpened_img = imsharpen(gray_img, 'Radius', 1.5, 'Amount', 1.2, 'Threshold', 0.1); % 自适应二值化 binary_img = imbinarize(sharpened_img, 'adaptive', 'Sensitivity', 0.7); inverted_img = ~binary_img; handles.binary_image = inverted_img; % 显示处理图像 axes(handles.ax_processed); imshow(inverted_img); title('二值化图像'); % 重置结果 set(handles.formula_text, 'String', ''); set(handles.calc_text, 'String', ''); set(handles.answer_text, 'String', ''); set(handles.result_text, 'String', ''); set(handles.equal_log, 'String', {}); axes(handles.ax_equal); cla; title('等号检测'); guidata(fig, handles); end function recognizeFormula(~, ~) handles = guidata(fig); if isempty(handles.current_image) errordlg('请先上传图像', '错误'); return; end try inverted_img = handles.binary_image; [img_h, img_w] = size(inverted_img); % ================= 第一步:区域分割 ================= axes(handles.ax_processed); imshow(inverted_img); title('区域分割'); drawnow; % 区域分割 cc = bwconncomp(inverted_img); stats = regionprops(cc, 'BoundingBox', 'Area', 'Eccentricity', 'Orientation', 'Solidity'); % 过滤噪点 min_area = max(20, img_h*img_w*0.0005); % 动态最小面积 valid_idx = [stats.Area] > min_area; stats = stats(valid_idx); % 按水平位置排序(从左到右) bboxes = vertcat(stats.BoundingBox); [~, order] = sort(bboxes(:,1)); bboxes = bboxes(order, :); stats = stats(order); % 存储区域信息 handles.region_stats = stats; handles.region_bboxes = bboxes; % 显示分割结果 imshow(inverted_img); hold on; for i = 1:size(bboxes,1) rectangle('Position', bboxes(i,:), 'EdgeColor', [0.8 0.2 0.2], 'LineWidth', 1); end hold off; title(sprintf('分割出 %d 个区域', length(stats))); drawnow; axes(handles.ax_equal); imshow(inverted_img); title('等号检测过程'); hold on; log_entries = {}; % ================= 第二步:等号检测(从左到右扫描相邻区域)================= equal_sign_index = []; merged_regions = false(1, length(stats)); % 标记已合并的区域 for i = 1:length(stats)-1 if merged_regions(i), continue; end % 跳过已合并的区域 bbox1 = bboxes(i,:); bbox2 = bboxes(i+1,:); % 计算区域中心位置 center1_x = bbox1(1) + bbox1(3)/2; center1_y = bbox1(2) + bbox1(4)/2; center2_x = bbox2(1) + bbox2(3)/2; center2_y = bbox2(2) + bbox2(4)/2; % 计算区域间距 dx = abs(center1_x - center2_x); dy = abs(center1_y - center2_y); % 计算水平重叠度 overlap_x = min(bbox1(1)+bbox1(3), bbox2(1)+bbox2(3)) - max(bbox1(1), bbox2(1)); overlap_ratio = overlap_x / max(bbox1(3), bbox2(3)); % 等号检测条件: % 1. 水平位置相近(水平中心距离小于最大宽度的60%) % 2. 垂直方向分离(垂直中心距离大于最小高度的40%) % 3. 水平重叠度大于30% % 4. 两个区域高度相近(高度比在0.5-2之间) height_ratio = min(bbox1(4), bbox2(4)) / max(bbox1(4), bbox2(4)); if dx < 0.6 * max(bbox1(3), bbox2(3)) && ... % 水平位置相近 dy > 0.2 * min(bbox1(4), bbox2(4)) && ... % 垂直方向分离 overlap_ratio > 0.3 && ... % 水平重叠足够 height_ratio > 0.5 && ... % 高度相近 height_ratio < 2 % 标记为等号候选 log_entries{end+1} = sprintf('区域 %d 和 %d 可能是等号组件', i, i+1); log_entries{end+1} = sprintf('-- 水平距离: %.1f, 垂直距离: %.1f, 重叠率: %.2f', dx, dy, height_ratio); % 提取区域图像进行分析 region_img1 = inverted_img(max(1,floor(bbox1(2))):min(img_h,floor(bbox1(2)+bbox1(4))-1), ... max(1,floor(bbox1(1))):min(img_w,floor(bbox1(1)+bbox1(3))-1)); region_img2 = inverted_img(max(1,floor(bbox2(2))):min(img_h,floor(bbox2(2)+bbox2(4))-1), ... max(1,floor(bbox2(1))):min(img_w,floor(bbox2(1)+bbox2(3))-1)); % 检查是否为横线结构 [is_line1, ~] = isHorizontalLine(region_img1); [is_line2, ~] = isHorizontalLine(region_img2); if is_line1 && is_line2 % 确定等号位置(使用第一个区域的索引) equal_sign_index = i; log_entries{end+1} = sprintf('确认区域 %d 和 %d 组成等号', i, i+1); % 标记这两个区域 rectangle('Position', bbox1, 'EdgeColor', [0 0.8 0], 'LineWidth', 2); rectangle('Position', bbox2, 'EdgeColor', [0 0.8 0], 'LineWidth', 2); text(bbox1(1)+bbox1(3)/2, bbox1(2)-15, '=', ... 'Color', [0 0.5 0], 'FontSize', 20, 'FontWeight', 'bold', ... 'HorizontalAlignment', 'center'); % 标记这两个区域已合并 merged_regions(i) = true; merged_regions(i+1) = true; % 创建合并后的等号区域 merged_bbox = [ min(bbox1(1), bbox2(1)), ... min(bbox1(2), bbox2(2)), ... max(bbox1(1)+bbox1(3), bbox2(1)+bbox2(3)) - min(bbox1(1), bbox2(1)), ... max(bbox1(2)+bbox1(4), bbox2(2)+bbox2(4)) - min(bbox1(2), bbox2(2)) ]; % 更新区域列表(用合并区域替换原来的两个区域) bboxes(i,:) = merged_bbox; bboxes(i+1,:) = []; % 删除第二个区域 % 更新区域统计信息 merged_stats = stats(i); merged_stats.BoundingBox = merged_bbox; stats(i) = merged_stats; stats(i+1) = []; % 更新合并标记 merged_regions(i+1:end) = []; merged_regions = [merged_regions(1:i) false(1, length(stats)-i)]; % 重绘区域编号 for j = 1:length(stats) bbox = stats(j).BoundingBox; rectangle('Position', bbox, 'EdgeColor', [0.8 0.2 0.2], 'LineWidth', 1); text(bbox(1)+5, bbox(2)-10, sprintf('%d', j), ... 'Color', [0.2 0.2 0.8], 'FontSize', 10, 'FontWeight', 'bold'); end break; % 找到一个等号后停止搜索 else log_entries{end+1} = sprintf('区域 %d 和 %d 不符合横线特征', i, i+1); end end end % 如果没有找到等号,使用中间位置作为等号 if isempty(equal_sign_index) [~, eq_idx] = min(abs(1:size(bboxes,1) - size(bboxes,1)/2)); log_entries{end+1} = sprintf('未找到等号,使用区域 %d 作为等号', eq_idx); equal_sign_index = eq_idx; % 标记等号区域 bbox = bboxes(eq_idx,:); rectangle('Position', bbox, 'EdgeColor', [0.9 0.6 0], 'LineWidth', 3); text(bbox(1)+bbox(3)/2, bbox(2)-15, '=', ... 'Color', [0.7 0.4 0], 'FontSize', 20, 'FontWeight', 'bold', ... 'HorizontalAlignment', 'center'); end hold off; % 更新日志 set(handles.equal_log, 'String', log_entries); % 存储等号位置和更新后的区域信息 handles.equal_sign_index = equal_sign_index; handles.region_stats = stats; handles.region_bboxes = bboxes; % ================= 第三步:字符识别 ================= ocr_results = cell(1, length(stats)); for i = 1:length(stats) % 如果是等号区域,直接标记 if i == equal_sign_index ocr_results{i} = '='; continue; end bbox = stats(i).BoundingBox; x = floor(bbox(1)); y = floor(bbox(2)); w = max(floor(bbox(3)), 1); h = max(floor(bbox(4)), 1); % 提取区域图像 region_img = inverted_img(max(1,y):min(img_h,y+h-1), max(1,x):min(img_w,x+w-1)); % 运算符特征检测 [is_operator, operator_type] = detectOperator(region_img); if is_operator ocr_results{i} = operator_type; else % OCR识别数字和字母 char_set = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; ocr_result = ocr(region_img, 'CharacterSet', char_set, 'TextLayout', 'Block'); if ~isempty(ocr_result.Text) char = strtrim(ocr_result.Text); % 数字校正 if strcmp(char, '7') || strcmp(char, '1') char = correctDigit(region_img, char); end ocr_results{i} = char; else ocr_results{i} = '?'; end end end % ================= 第四步:构建表达式 ================= % 分割表达式和答案 expr_str = ''; answer_str = ''; for i = 1:length(ocr_results) if i < equal_sign_index expr_str = [expr_str ocr_results{i}]; elseif i > equal_sign_index answer_str = [answer_str ocr_results{i}]; end end % 特殊字符转换 expr_str = strrep(expr_str, 'x', '*'); expr_str = strrep(expr_str, 'X', '*'); expr_str = strrep(expr_str, '÷', '/'); expr_str = strrep(expr_str, ' ', ''); % 尝试转换为数值 try user_answer = str2double(answer_str); catch user_answer = NaN; end % 安全计算表达式 try correct_result = eval(expr_str); catch % 修正常见OCR错误 expr_str = strrep(expr_str, 'O', '0'); expr_str = strrep(expr_str, 'o', '0'); expr_str = strrep(expr_str, 'l', '1'); expr_str = strrep(expr_str, 'I', '1'); expr_str = strrep(expr_str, 's', '5'); correct_result = eval(expr_str); end % 验证结果 is_correct = abs(user_answer - correct_result) < 1e-6; % 更新结果展示 set(handles.formula_text, 'String', [expr_str '=' answer_str]); set(handles.calc_text, 'String', num2str(correct_result)); set(handles.answer_text, 'String', num2str(user_answer)); if is_correct set(handles.result_text, 'String', '✓ 答案正确', 'ForegroundColor', [0 0.6 0]); else set(handles.result_text, 'String', '✗ 答案错误', 'ForegroundColor', [0.8 0 0]); end % 显示最终识别结果 axes(handles.ax_processed); imshow(inverted_img); hold on; for i = 1:length(stats) bbox = stats(i).BoundingBox; % 等号区域用绿色标注 if i == equal_sign_index rectangle('Position', bbox, 'EdgeColor', [0.2 0.8 0.2], 'LineWidth', 2); text(bbox(1)+5, bbox(2)-10, '=', ... 'Color', [0 0.5 0], 'FontSize', 12, 'FontWeight', 'bold'); else % 运算符区域用不同颜色标注 if strcmp(ocr_results{i}, '+') rect_color = [0.8 0.2 0.8]; % 紫色 text_color = [0.6 0 0.6]; % 深紫色 elseif strcmp(ocr_results{i}, '-') rect_color = [0.8 0.5 0.2]; % 橙色 text_color = [0.6 0.3 0]; % 深橙色 else rect_color = [1 0 0]; % 红色 text_color = [0 0 1]; % 蓝色 end rectangle('Position', bbox, 'EdgeColor', rect_color, 'LineWidth', 1.5); if ~isempty(ocr_results{i}) text(bbox(1)+5, bbox(2)-10, ocr_results{i}, ... 'Color', text_color, 'FontSize', 10, 'FontWeight', 'bold'); end end end hold off; title('最终识别结果'); % 保存处理后的数据 handles.ocr_results = ocr_results; guidata(fig, handles); catch ME errordlg(sprintf('识别失败: %s', ME.message), '错误'); end end function clearResults(~, ~) handles = guidata(fig); % 清除结果文本 set(handles.formula_text, 'String', ''); set(handles.calc_text, 'String', ''); set(handles.answer_text, 'String', ''); set(handles.result_text, 'String', ''); set(handles.equal_log, 'String', {}); % 清除图像 axes(handles.ax_processed); cla; title('处理图像'); axes(handles.ax_equal); cla; title('等号检测'); % 如果有原始图像,重新显示 if ~isempty(handles.current_image) axes(handles.ax_original); imshow(handles.current_image); title('原始图像'); end end end % ======================== 辅助函数 ======================== function [is_line, confidence] = isHorizontalLine(img) % 检测区域是否为水平线 [h, w] = size(img); % 基本检查 if h == 0 || w == 0 || sum(img(:)) == 0 is_line = false; confidence = 0; return; end % 计算特征 aspect_ratio = w / h; fill_ratio = sum(img(:)) / (h*w); % 水平投影 horizontal_proj = sum(img, 2); max_proj = max(horizontal_proj); if max_proj == 0 is_line = false; confidence = 0; return; end % 找到主要行 [~, main_row] = max(horizontal_proj); line_height = sum(horizontal_proj > 0.5 * max_proj); % 置信度计算 aspect_conf = min(1, aspect_ratio / 3); % 宽高比越大越好 height_conf = max(0, 1 - (line_height-1)/3); % 行高越接近1越好 fill_conf = min(1, fill_ratio * 3); % 填充率适中 confidence = 0.5 * aspect_conf + 0.3 * height_conf + 0.2 * fill_conf; % 决策阈值 is_line = confidence > 0.2 && aspect_ratio > 1.1 && line_height <= 8; end % ======================== 运算符检测函数 ======================== function [is_operator, operator_type] = detectOperator(region_img) [h, w] = size(region_img); % 计算形状特征 aspect_ratio = w / h; eccentricity = regionprops(region_img, 'Eccentricity').Eccentricity; is_operator = false; operator_type = ''; % 减号检测 if aspect_ratio > 3 && eccentricity > 0.9 is_operator = true; operator_type = '-'; return; end % 加号检测 if aspect_ratio > 1.2 && aspect_ratio < 2.5 % 中心区域分析 center_y = round(h/2); center_x = round(w/2); % 检查水平和垂直线段 horizontal_line = sum(region_img(center_y, :)) > w*0.7; vertical_line = sum(region_img(:, center_x)) > h*0.7; if horizontal_line && vertical_line is_operator = true; operator_type = '+'; return; end end % 乘号检测(斜线) if aspect_ratio > 0.8 && aspect_ratio < 1.2 % 使用Hough变换检测斜线 [H, theta, rho] = hough(region_img, 'Theta', -45:5:45); peaks = houghpeaks(H, 2); if size(peaks,1) >= 2 angles = theta(peaks(:,2)); angle_diff = abs(diff(angles)); % 检查是否接近垂直的斜线对 if abs(angle_diff) > 80 && abs(angle_diff) < 100 is_operator = true; operator_type = '*'; end end end end % ======================== 数字校正函数 ======================== function char = correctDigit(region_img, original_char) [h, w] = size(region_img); % 1的特征:高宽比大,顶部无横线,底部较宽 aspect_ratio = h / w; top_region = region_img(1:round(h*0.3), :); bottom_region = region_img(round(h*0.7):end, :); top_pixels = sum(top_region(:)); bottom_pixels = sum(bottom_region(:)); % 7的特征:顶部有横线,右上角有折角 top_line = sum(region_img(1, :)) > w*0.6; right_top_corner = region_img(1, end) && region_img(2, end); if strcmp(original_char, '7') % 检查是否为1的特征 if aspect_ratio > 3 && top_pixels < numel(top_region)*0.2 && bottom_pixels > numel(bottom_region)*0.5 char = '1'; return; end elseif strcmp(original_char, '1') % 检查是否为7的特征 if aspect_ratio < 2 && top_line && right_top_corner char = '7'; return; end end char = original_char; % 保持原识别结果 end 代码运行显示,运算符的使用无效,是否是识别不出来各个字符
06-16
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