简介

最近用爬虫爬了几千张高清图片回来，由于图片质量太高（几千x几千的分辨率，一张图几十MB），连平常浏览都费劲。因此，就用photoshop自带的ExtendScript Toolkit脚本工具写了个缩图脚本。

脚本支持正常的另存为JPG和PNG，也支持"储存为Wwb所用格式"的JPG和PNG。

使用方式

1. 先把代码保存为"缩图脚本.jsx"之类的.jsx结尾的文本文件（脚本语言实际上是javascript）。
2. 根据自己的需求修改文件开头定义的值：

• INPUT_PATH 输入路径。准备要处理的图片所在的文件夹。
• OUTPUT_PATH 输出路径。保存缩小后的图片所在的文件夹。
• LIMIT_SIZE 最大边长。宽或者高超过该值的图片都会被等比例缩小至该值。
• SAVE_FORMAT 保存格式[jpg, png, webjpg, webpng]。
• SAVE_QUALITY 图片质量[0, 100]。数值越大图片质量越高
• TEST_MODE 画质测试模式。该模式下只会处理一张图片，但会输出各种格式及图片质量的图，作为批量输出前缩放画质的参考。

3. 然后将修改好的脚本直接拖进photoshop中就能运行了。

#target photoshop

var INPUT_PATH = 'C:\\Users\\Administrator\\Desktop\\input'		//输入路径
var OUTPUT_PATH = 'C:\\Users\\Administrator\\Desktop\\output'	//输出路径
var LIMIT_SIZE = 1024		// 最大边长
var SAVE_FORMAT = 'webpng'	// 保存格式 jpg, png, webjpg, webpng
var SAVE_QUALITY = 60		// 图片质量[0, 100]
var TEST_MODE = false		// 画质测试模式

function Main(){
	if(TEST_MODE==true)
	{
		TestMode();
		alert("脚本执行完毕");
		return;
	}
	
	fileOut = new File(OUTPUT_PATH + "\\PhotoShop.log");
	fileOut.open("w", "TEXT", "????");
	fileOut.write("开始批处理\n");
	
	var input_folder = new Folder(INPUT_PATH);
	if(input_folder!=null)
	{
		var files = input_folder.getFiles ("*.*");
		
		var i=0;
		while(files[i]!=null ){
			var fp = app.open(new File(files[i]));
			if(fp !=null){
				try{
					Resize(LIMIT_SIZE);
					
					var filename = fp.name.substring(0,fp.name.lastIndexOf("."));
					Save(OUTPUT_PATH, filename, SAVE_FORMAT, SAVE_QUALITY);
					app.activeDocument.close(SaveOptions.DONOTSAVECHANGES);
				}catch(e){
					//alert (e.name + ": " + e.message);
					fileOut.write(e.name + ": " + e.message+"\n");
				}
			}
			i++;
		}
		alert("脚本执行完毕");
	}
	fileOut.write("批处理结束\n");
}

function Resize(LimitSize){
	var w = app.activeDocument.width.value;
	var h = app.activeDocument.height.value;
	if(w> LimitSize || h >LimitSize){
		if(w>h){
				var per=LimitSize/w*100;
				app.activeDocument.resizeImage(per+"%",per+"%", null, ResampleMethod.BICUBICSHARPER);
		}
		else{
				var per=LimitSize/h*100;
				app.activeDocument.resizeImage(per+"%",per+"%", null, ResampleMethod.BICUBICSHARPER);
		}
	}
}

function TestMode(){
	var input_folder = new Folder(INPUT_PATH);
	if(input_folder!=null)
	{
		var files = input_folder.getFiles ("*.*");
		var fp = app.open(new File(files[0]));
		if(fp !=null){
			Resize(LIMIT_SIZE);

			// jpg test
			Save(OUTPUT_PATH, 'jpg_0', 'jpg', 0);
			Save(OUTPUT_PATH, 'jpg_30', 'jpg', 30);
			Save(OUTPUT_PATH, 'jpg_60', 'jpg', 60);
			Save(OUTPUT_PATH, 'jpg_80', 'jpg', 80);
			Save(OUTPUT_PATH, 'jpg_100', 'jpg', 100);
			
			// png test
			Save(OUTPUT_PATH, 'png_0', 'png', 0);
			Save(OUTPUT_PATH, 'png_30', 'png', 30);
			Save(OUTPUT_PATH, 'png_60', 'png', 60);
			Save(OUTPUT_PATH, 'png_80', 'png', 80);
			Save(OUTPUT_PATH, 'png_100', 'png', 100);
			
			// webjpg test
			Save(OUTPUT_PATH, 'webjpg_0', 'webjpg', 0);
			Save(OUTPUT_PATH, 'webjpg_30', 'webjpg', 30);
			Save(OUTPUT_PATH, 'webjpg_60', 'webjpg', 60);
			Save(OUTPUT_PATH, 'webjpg_80', 'webjpg', 80);
			Save(OUTPUT_PATH, 'webjpg_100', 'webjpg', 100);
			
			// webpng test
			Save(OUTPUT_PATH, 'webpng_0', 'webpng', 0);
			Save(OUTPUT_PATH, 'webpng_30', 'webpng', 30);
			Save(OUTPUT_PATH, 'webpng_60', 'webpng', 60);
			Save(OUTPUT_PATH, 'webpng_80', 'webpng', 80);
			Save(OUTPUT_PATH, 'webpng_100', 'webpng', 100);
			
			app.activeDocument.close(SaveOptions.DONOTSAVECHANGES);
		}
	}
}

//format: jpg, png, webjpg, webpng
//quality: [0, 100]
function Save(savePath, filename, format, quality){
	saveFile = OUTPUT_PATH+"\\"+filename
	if(format == 'jpg'){
		saveFile += '.jpg'
		q = Math.round(quality / 100 * 12)
		SaveJPEG(saveFile, q)
	}else if(format == 'png'){
		saveFile += '.png'
		q = Math.round((100-quality) / 100 * 9)
		SavePNG(saveFile, q)
	}else if(format == 'webjpg'){
		saveFile += '.jpg'
		SaveForWeb(saveFile, SaveDocumentType.JPEG, quality)
	}else if(format == 'webpng'){
		saveFile += '.png'
		SaveForWeb(saveFile, SaveDocumentType.PNG-24, quality)
	}else{
		saveFile += '.jpg'
		SaveForWeb(saveFile, SaveDocumentType.JPEG, quality)
	}
}

function SaveJPEG(saveFile, quality){
	jpgSaveOptions = new JPEGSaveOptions();
	
	// embedColorProfile (True to embed the color profile in the document.)
	jpgSaveOptions.embedColorProfile = true;
	
	// formatOptions (The download format to use.)
	// Default: FormatOptions.STANDARDBASELINE 
	// Range: FormatOptions.STANDARDBASELINE, 
	//			FormatOptions.OPTIMIZEDBASELINE, 
	//			FormatOptions.PROGRESSIVE
	jpgSaveOptions.formatOptions = FormatOptions.STANDARDBASELINE;
	
	// matte (The color to use to fill anti-aliased edges adjacent to transparent areas of the image. 
	//			When transparency is turned off for an image, the matte color is applied to transparent areas.)
	// Default: MatteType.WHITE
	// Range: MatteType.BACKGROUND
	//			MatteType.BLACK
	//			MatteType.FOREGROUND
	//			MatteType.NETSCAPE
	//			MatteType.NONE
	//			MatteType.SEMIGRAY
	//			MatteType.WHITE
	jpgSaveOptions.matte = MatteType.NONE;
	
	// quality (The image quality setting to use; affects file size and compression)
	// Default: 3 
	// Range: [0,12]
	jpgSaveOptions.quality = quality;
	
	// scans (The number of scans to make to incrementally display the image on the page. 
	//			Valid only for when formatOptions = FormatOptions.PROGRESSIVE.)
	// Default: 3
	// Range: [3,5]
	//jpgSaveOptions.scans = 3
	
	// typename (The class name of the referenced JPEGSaveOptions object.)
	// Read only
	//jpgSaveOptions.typename
	
	activeDocument.saveAs(new File(saveFile), jpgSaveOptions, true,Extension.LOWERCASE);
}

function SavePNG(saveFile, compression){
	pngSaveOptions = new PNGSaveOptions();

	// compression (The compression value)
	// Default: 0
	// Range: [0,9]
	pngSaveOptions.compression = compression
	
	// interlaced (True to interlace rows)
	// Default: false
	pngSaveOptions.interlaced = false
	
	// typename (The class name of the referenced PNGSaveOptions object.)
	// Read only
	//pngSaveOptions.typename
	
	activeDocument.saveAs(new File(saveFile), pngSaveOptions, true,Extension.LOWERCASE);
}

function SaveForWeb(saveFile, format, quality){
	
	var webSaveOptions = new ExportOptionsSaveForWeb(); 
	
	// blur (Applies blur to the image to reduce artifacts)
	// Default: 0.0
	webSaveOptions.blur = 0.0; 
	
	// colorReduction (The color reduction algorithm.)
	// Default: ColorReductionType.SELECTIVE 
	// Range: ColorReductionType.PERCEPTUAL, 
	//			ColorReductionType.SELECTIVE, 
	//			ColorReductionType.ADAPTIVE, 
	//			ColorReductionType.RESTRICTIVE, 
	//			ColorReductionType.CUSTOM, 
	//			ColorReductionType.BLACKWHITE
	//			ColorReductionType.GRAYSCALE, 
	//			ColorReductionType.MACINTOSH
	//			ColorReductionType.WINDOWS
	webSaveOptions.colorReduction = ColorReductionType.SELECTIVE 
	
	// colors (The number of colors in the palette.)
	// Default: 256 
	webSaveOptions.colors = 256
	
	// dither (The type of dither)
	// Default: Dither.DIFFUSION
	// Range: Dither.DIFFUSION
	//			Dither.NOISE
	//			Dither.NONE
	//			Dither.PATTERN
	webSaveOptions.dither = Dither.DIFFUSION
	
	// ditherAmount (The amount of dither.Valid only when dither = Dither.DIFFUSION)
	// Default: 100
	webSaveOptions.ditherAmount = 100;
	
	// format (The file format to use)
	// Ddefault: SaveDocumentType.COMPUSERVEGIF
	// Range: SaveDocumentType.COMPUSERVEGIF, 
	//			SaveDocumentType.JPEG, 
	//			SaveDocumentType.PNG-8, 
	//			SaveDocumentType.PNG-24, 
	//			SaveDocumentType.BMP
	webSaveOptions.format = SaveDocumentType.JPEG; 
	
	// includeProfile (True to include the document’s embedded color profile)
	// Default: false
	webSaveOptions.includeProfile = false; 
	
	// interlaced (True to download in multiple passes progressive)
	// Default: false
	webSaveOptions.interlaced = false; 
	
	// lossy (The amount of lossiness allowed)
	// Default: 0
	webSaveOptions.lossy = 0;
	
	// matteColor (The colors to blend transparent pixels against.)
	// Type: RGBColor
	//webSaveOptions.matteColor ;
	
	// optimized (True to create smaller but less compatible files. Valid only when format = SaveDocumentType.JPEG.)
	// Default: true
	webSaveOptions.optimized = true; 

	// PNG8 (Indicates the number of bits; true = 8, false = 24. Valid only when format = SaveDocumentType.PNG.)
	// Default: true
	webSaveOptions.PNG8 = true;

	// quality (The quality of the produced image as a percentage)
	// Default: 60
	// Range: [0, 100]
	webSaveOptions.quality = quality;
	
	// transparency (Indication of transparent areas of the image should be included in the saved image)
	// Default: true
	webSaveOptions.transparency = true;
	
	// transparencyAmount (The amont of transparency dither. Valid only if transparency = true.)
	// Default: 100
	webSaveOptions.transparencyAmount = 100;
	
	// transparencyDither (The transparency dither algorithm)
	// Default: Dither.NONE
	// Range: Dither.DIFFUSION
	//			Dither.NOISE
	//			Dither.NONE
	//			Dither.PATTERN
	webSaveOptions.transparencyDither = Dither.NONE
	
	// typename (The class name of the referenced ExportOptionsSaveForWeb object.)
	// Read only
	//webSaveOptions.typename
	
	// webSnap (The tolerance amount within which to snap close colors to web palette colors)
	// Default: 0
	webSaveOptions.webSnap = 0;
	
	activeDocument.exportDocument(new File(saveFile), ExportType.SAVEFORWEB, webSaveOptions);
}



Main();
//alert ("finish");