--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/streamlet-examples/barcode-reader.cpp Sat May 01 18:18:01 2021 +0200
@@ -0,0 +1,214 @@
+/**
+ * Relational pipes
+ * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <unistd.h>
+
+#include <Magick++.h>
+#include <zbar.h>
+
+#include <relpipe/xmlwriter/XMLWriter.h>
+
+#include "streamlet-common.h"
+
+/**
+ * This streamlet extracts QR codes from image files.
+ *
+ * It provides three attributes:
+ * - qr: first QR code found (if any)
+ * - qr_count: number of QR codes found
+ * - qr_xml: XML containing all QR cpdes found an additional metadata
+ *
+ * Options:
+ * - value-pattern: regular expression describing expected value of QR code;
+ * if one or more options are given, the "qr" attribute will contain first value matching any of these patterns
+ *
+ */
+class QRStreamlet : public Streamlet {
+private:
+
+ const wstring XMLNS = L"tag:globalcode.info,2018:barcode";
+
+ class Point {
+ public:
+ int x;
+ int y;
+ };
+
+ class Symbol {
+ public:
+ int id;
+ std::wstring value;
+ std::wstring type;
+ int x;
+ int y;
+ int width;
+ int height;
+ std::vector<Point> polygon;
+ };
+
+ std::vector<Symbol> findSymbols(std::wstring fileName) {
+ std::vector<Symbol> result;
+
+ Magick::Image magick(toBytes(fileName));
+ int width = magick.columns();
+ int height = magick.rows();
+ Magick::Blob blob;
+ magick.modifyImage();
+ magick.write(&blob, "GRAY", 8);
+ const void *raw = blob.data();
+
+ zbar::Image image(width, height, "Y800", raw, width * height);
+ zbar::ImageScanner scanner;
+
+ scanner.scan(image);
+
+ int id = 0;
+ for (zbar::Image::SymbolIterator symbol = image.symbol_begin(); symbol != image.symbol_end(); ++symbol, id++) {
+ Symbol s;
+
+
+ s.id = id;
+ s.type = fromBytes(symbol->get_type_name());
+ s.value = fromBytes(symbol->get_data());
+
+ int minX = 0;
+ int minY = 0;
+ int maxX = 0;
+ int maxY = 0;
+
+ // TODO: return original polygon in XML
+ for (int i = 0, locationSize = symbol->get_location_size(); i < locationSize; i++) {
+ int x = symbol->get_location_x(i);
+ int y = symbol->get_location_y(i);
+ minX = minX ? std::min(minX, x) : x;
+ minY = minY ? std::min(minY, y) : y;
+ maxX = std::max(maxX, x);
+ maxY = std::max(maxY, y);
+ s.polygon.push_back({x, y});
+ }
+
+ s.x = minX;
+ s.y = minY;
+ s.width = maxX - minX;
+ s.height = maxY - minY;
+
+ result.push_back(s);
+ }
+
+
+
+ return result;
+ }
+
+ bool matchesAny(const std::wstring& value, const std::vector<std::wregex>& valuePatterns) {
+ for (const std::wregex& pattern : valuePatterns) {
+ if (std::regex_match(value, pattern)) return true;
+ }
+ return false;
+ }
+
+ std::vector<std::wregex> getOptionsAsPatterns(std::wstring optionName) {
+ std::vector<std::wregex> result;
+ for (Option o : getOptions(optionName)) result.push_back(std::wregex(o.value));
+ return result;
+ }
+
+protected:
+
+ std::vector<AttributeMetadata> getOutputAttributesMetadata() override {
+ std::vector<AttributeMetadata> oam;
+ int i = 0;
+ oam.push_back({getAlias(i++, L"barcode"), STRING});
+ oam.push_back({getAlias(i++, L"barcode_count"), INTEGER});
+ oam.push_back({getAlias(i++, L"barcode_xml"), STRING});
+ return oam;
+ }
+
+ std::vector<OutputAttribute> getOutputAttributes() override {
+ bool matchedFile = false;
+ bool validInput = false;
+ bool matchedFirst = false;
+ std::wstring first;
+ std::stringstream xml;
+
+ std::vector<std::wregex> filePatterns = getOptionsAsPatterns(L"file-pattern");
+ matchedFile = filePatterns.size() == 0 || matchesAny(getCurrentFile(), filePatterns);
+
+ std::vector<Symbol> symbols;
+ if (matchedFile) {
+ try {
+ symbols = findSymbols(getCurrentFile());
+ validInput = true;
+ } catch (...) {
+ // just ignore the errors;
+ // the file is probably not an image or we do not have read permissions
+ validInput = false;
+ }
+
+ std::vector<std::wregex> valuePatterns = getOptionsAsPatterns(L"value-pattern");
+
+ for (Symbol s : symbols) {
+ if (valuePatterns.size() == 0 || matchesAny(s.value, valuePatterns)) {
+ first = s.value;
+ matchedFirst = true;
+ break;
+ }
+ }
+
+ relpipe::xmlwriter::XMLWriter xmlWriter(xml);
+ xmlWriter.writeStartElement(L"barcodes-recognized",{L"xmlns", XMLNS});
+
+ // TODO: common metadata
+ // xmlWriter.writeStartElement(L"source");
+ // xmlWriter.writeTextElement(L"height",{}, std::to_wstring(...));
+ // xmlWriter.writeTextElement(L"width",{}, std::to_wstring(...));
+ // xmlWriter.writeEndElement();
+
+ for (Symbol s : symbols) {
+ xmlWriter.writeStartElement(L"symbol");
+ xmlWriter.writeTextElement(L"value",{}, s.value);
+
+ // TODO: well-designed XML schema
+ // TODO: synchronize/share common XML parts with relpipe-in-qr
+ xmlWriter.writeStartElement(L"rectangular-box");
+ xmlWriter.writeTextElement(L"x",{}, std::to_wstring(s.x));
+ xmlWriter.writeTextElement(L"y",{}, std::to_wstring(s.y));
+ xmlWriter.writeTextElement(L"height",{}, std::to_wstring(s.height));
+ xmlWriter.writeTextElement(L"width",{}, std::to_wstring(s.width));
+ xmlWriter.writeEndElement();
+
+ xmlWriter.writeStartElement(L"polygon");
+ for (Point p : s.polygon) xmlWriter.writeEmptyElement(L"point",{L"x", std::to_wstring(p.x), L"y", std::to_wstring(p.y)});
+ xmlWriter.writeEndElement();
+
+ xmlWriter.writeEndElement();
+ }
+
+ xmlWriter.writeEndElement();
+
+ }
+
+ std::vector<OutputAttribute> oa;
+ // TODO: report also validInput and matchedFile (distinguish them from matchedFirst)?
+ oa.push_back({first, !matchedFirst});
+ oa.push_back({std::to_wstring(symbols.size()), !matchedFile});
+ oa.push_back({fromBytes(xml.str()), !matchedFile});
+ return oa;
+ }
+};
+
+STREAMLET_RUN(QRStreamlet)