为什么这里一定要说 windows 系统是64位呢，因为如果是系统是64位，那么PHP5.5 一般都会选择64的， Imagemagick 组件也会选择64位的， 但是操蛋的是 64位的Imagemagick 组件，怎么弄都失败。 所以没有办法：php 和 Imagemagick 都换成32位的，一试 就OK 了。
国外网站，也有多个网站反馈 64位的Imagemagick不行
PHP 5.5:
这个版本没有了，我用的是 php-5.5.30-nts-Win32-VC11-x86.zip 这个版本Imagemagick:
php_imagick.dll :
国外网友的资料：
So after 4 hours I got it working: You got Windows (x32 o x64) and IIS. You want PHP 5.5 and Imagemagick. !! : Everything (PHP, Imagemagick installation, php_imagick.dll) needs to be x86 (32bit) for now (x64 builds are still experimental). Tested and working: Windows: 2008R2 x64 SP1 Visual C++ 2012 redist x86 and x64: ---这个我没有安装，因为我电脑已经安装了Visual C++ 2012 开发环境了。 PHP 5.5: 5.5.8 VC11 x86 Non Thread Safe (2014-Jan-09 18:16:08) ... all php5.5.x x86 nts should work ... Imagemagick: ImageMagick-6.8.4-0 Q16 x86 dll (you can try newer 6.8.4.x versions, but allways -x86-dll) ... install to c:\imagemagick and during install check "add to system path" ... php_imagick.dll : get it from this site: : version: Imagick for PHP 5.5.x, MSVC11 (Visual C++ 2012 Express), x86, Non Thread Safe, Build Date: Jul 9th, 2013 22:26:55 (CET), Download: php_imagick.dll (244 Kio) copy to php\ext dir ane add this extension to php.ini ... restart IIs (or windows) and ... done 
原文地址：http://www.imagemagick.org/discourse-server/viewtopic.php?t=23780
PHP Fatal error: Uncaught exception 'ImagickException' with message 'no decode delegate for this image format `PNG' ---错误的解决方案：
imagick
| imagick module | enabled |
|---|---|
| imagick module version | 3.1.2 |
| imagick classes | Imagick, ImagickDraw, ImagickPixel, ImagickPixelIterator |
| ImageMagick version | ImageMagick 6.9.2-8 Q16 i686 2015-12-16 http://www.imagemagick.org |
| ImageMagick copyright | Copyright (C) 1999-2015 ImageMagick Studio LLC |
| ImageMagick release date | 2015-12-16 |
| ImageMagick number of supported formats: | 217 |
| ImageMagick supported formats | 3FR, A, AAI, AI, ART, ARW, AVI, AVS, B, BGR, BGRA, BGRO, BMP, BMP2, BMP3, BRF, C, CAL, CALS, CANVAS, CAPTION, CIN, CIP, CLIP, CMYK, CMYKA, CR2, CRW, CUR, CUT, DATA, DCM, DCR, DCX, DDS, DFONT, DNG, DPX, DXT1, DXT5, EPDF, EPI, EPS, EPS2, EPS3, EPSF, EPSI, EPT, EPT2, EPT3, ERF, FAX, FITS, FRACTAL, FTS, G, G3, GIF, GIF87, GRADIENT, GRAY, GROUP4, H, HALD, HDR, HISTOGRAM, HRZ, HTM, HTML, ICB, ICO, ICON, IIQ, INFO, INLINE, IPL, ISOBRL, ISOBRL6, JNX, JPE, JPEG, JPG, JPS, JSON, K, K25, KDC, LABEL, M, M2V, M4V, MAC, MAGICK, MAP, MASK, MAT, MATTE, MEF, MIFF, MKV, MONO, MOV, MP4, MPC, MPEG, MPG, MRW, MSL, MSVG, MTV, MVG, NEF, NRW, NULL, O, ORF, OTB, OTF, PAL, PALM, PAM, PANGO, PATTERN, PBM, PCD, PCDS, PCL, PCT, PCX, PDB, PDF, PDFA, PEF, PES, PFA, PFB, PFM, PGM, PICON, PICT, PIX, PJPEG, PLASMA, PNM, PPM, PREVIEW, PS, PS2, PS3, PSB, PSD, PTIF, PWP, R, RADIAL-GRADIENT, RAF, RAS, RAW, RGB, RGBA, RGBO, RGF, RLA, RLE, RMF, RW2, SCR, SCREENSHOT, SCT, SFW, SGI, SHTML, SIX, SIXEL, SPARSE-COLOR, SR2, SRF, STEGANO, SUN, SVG, SVGZ, TEXT, TGA, THUMBNAIL, TIFF, TIFF64, TILE, TIM, TTC, TTF, TXT, UBRL, UBRL6, UIL, UYVY, VDA, VICAR, VID, VIFF, VIPS, VST, WBMP, WMV, WPG, X, X3F, XBM, XC, XCF, XPM, XPS, XV, XWD, Y, YCbCr, YCbCrA, YUV |
---3.1.2的 imagick 不支持png，其实文档已经说的很明白了....