feat(options): add blur option plus documentation (#24)

fixes #20

README.md

@@ -5,8 +5,16 @@ SQIP - SVG-Based Image Placeholder
 "SQIP" (pronounced \skwɪb\ like the non-magical folk of magical descent) is a
 SVG-based [LQIP](https://www.guypo.com/introducing-lqip-low-quality-image-placeholders/) technique.
 
-**LQIP | SQIP | Original in comparison**
-[![LQIP vs. SQIP](demo/lqip-vs-sqip.jpg)](https://raw.githubusercontent.com/technopagan/sqip/master/demo/lqip-vs-sqip.jpg)
+## Examples
+
+| Original | LQIP | SQIP default | SQIP complex         |
+|----------|------|--------------|----------------------|
+| <img width="180" src="demo/beach.jpg"> | <img width="180" src="demo/beach-lqip.jpg"> | <img width="180" src="demo/beach-sqip.svg"> | <img width="180" src="./demo/beach-sqip-no-blur-50-all-shapes.svg"> |
+| Size: | 354B  (gz: 282B) | 895B (gz: 479B)| 3104B (gz: 1241B)- 50 shapes |
+| <img width="180" src="./demo/monkey-selfie.jpg"> | <img width="180" src="./demo/monkey-selfie-lqip.jpg"> | <img width="180" src="./demo/monkey-selfie-sqip.svg"> | <img width="180" src="./demo/monkey-selfie-sqip-no-blur-25-all-shapes.svg"> |
+| Size: | 435B (gz: 369B) | 980B (gz: 513B)| 2258B (gz: 924B) - 25 shapes |
+| <img width="180" src="./demo/mona-lisa.jpg"> | <img width="180" src="./demo/mona-lisa-lqip.jpg"> | <img width="180" src="./demo/mona-lisa-sqip.svg"> | <img width="180" src="./demo/mona-lisa-sqip-3-blur-50-triangles.svg"> |
+| Size: | 442B (gz: 372B) | 937B (gz: 487B) | 3273B (gz: 1394B)- 50 triangles |
 
 ## Requirements
 * Node.js >= v.6 (https://nodejs.org/en/)
@@ -97,6 +105,9 @@ sqip -n 4 input.jpg
 # Specify the type of primitive shapes that will be used to generate the image (default=0)
 # 0=combo, 1=triangle, 2=rect, 3=ellipse, 4=circle, 5=rotatedrect, 6=beziers, 7=rotatedellipse, 8=polygon
 sqip -m 4 input.jpg
+
+# Set the gaussian blur (default=12)
+sqip -b 3 input.jpg
 ```
 
 ### NODE API
@@ -107,6 +118,7 @@ Input options:
 - filename (required)
 - numberOfPrimitives (default=8)
 - mode (default=0)
+- blur (default=12)
 
 Returns:
 - final_svg - string

src/index.js

@@ -53,6 +53,13 @@ const argvOptions = [{
                 0=combo, 1=triangle, 2=rect, 3=ellipse, 4=circle, 5=rotatedrect,
                 6=beziers, 7=rotatedellipse, 8=polygon`,
         example: "'sqip --mode=3' or 'sqip -m 3'"
+    },
+    {
+        name: 'blur',
+        short: 'b',
+        type: 'int',
+        description: `GaussianBlur SVG filter value. Disable via 0, defaults to 12`,
+        example: "'sqip --blur=3' or 'sqip -b 3'"
     }
 ];
 const getArguments = () => argv.option(argvOptions).run();
@@ -140,18 +147,22 @@ const patchSVGGroup = (svg) => {
 // Add viewbox and preserveAspectRatio attributes as well as a Gaussian Blur filter to the SVG
 // When missing, add group (element with blur applied) using patchSVGGroup()
 // We initially worked with a proper DOM parser to manipulate the SVG's XML, but it was very opinionated about SVG syntax and kept introducing unwanted tags. So we had to resort to RegEx replacements
-const replaceSVGAttrs = (svg, { width, height }) => {
-  let blurStdDev = 12;
+const replaceSVGAttrs = (svg, { width, height, blur }) => {
+  let filter = '';
+  let blurStdDev = blur;
   let blurFilterId = 'b';
   let newSVG = svg;
-  if (svg.match(/<svg.*?><path.*?><g/) === null) {
-    blurStdDev = 55;
-    newSVG = patchSVGGroup(newSVG);
-    blurFilterId = 'c';
-  } else {
-    newSVG = newSVG.replace(/(<g)/, '<g filter="url(#b)"');
+  if (blur) {
+    if (svg.match(/<svg.*?><path.*?><g/) === null) {
+        blurStdDev = 55;
+        newSVG = patchSVGGroup(newSVG);
+        blurFilterId = 'c';
+    } else {
+        newSVG = newSVG.replace(/(<g)/, `<g filter="url(#${blurFilterId})"`);
+    }
+    filter = `<filter id="${blurFilterId}"><feGaussianBlur stdDeviation="${blurStdDev}" /></filter>`
   }
-  return newSVG.replace(/(<svg)(.*?)(>)/,`<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${width} ${height}"><filter id="${blurFilterId}"><feGaussianBlur stdDeviation="${blurStdDev}" /></filter>`);
+  return newSVG.replace(/(<svg)(.*?)(>)/,`<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${width} ${height}">${filter}`);
 }
 
 // If the user chooses to save the SVG to a file using the --output parameter, write the file
@@ -174,11 +185,18 @@ const printFinalResult = ({ width, height }, filename, svg_base64encoded) => {
 //#############################################################################
 
 const main = (filename, options) => {
-    const img_dimensions = getDimensions(filename);
+    const img_dimensions = getDimensions(filename)
+    const svgOptions = Object.assign({
+        blur: options.blur
+    }, img_dimensions);
+
+    // Do not pass blur to primitive
+    delete options.blur
+
     runPrimitive(filename, options, primitive_output_file, img_dimensions);
     const primitive_output = readPrimitiveTempFile(primitive_output_file);
     const svgo_output = runSVGO(primitive_output);
-    const final_svg = replaceSVGAttrs(svgo_output, img_dimensions);
+    const final_svg = replaceSVGAttrs(svgo_output, svgOptions);
     const svg_base64encoded = encodeBase64(final_svg);
 
     return { final_svg, svg_base64encoded, img_dimensions };