https://www.marykomelvenypoet.com/themes/misuraca-thumbnails-slideshow/js/resizeImageFunction.js

1function resize($image){
2	                var textDescriptHeight;
3	                //use set minimum incase people type a novel!
4	                if ($('#image_text').height() < 90)
5	                {
6		                if ($('#image_text').height() < 50) {
7	                		textDescriptHeight = 50;
8	                	} else {
9		                	textDescriptHeight = $('#image_text').height();
10	                	}
11	                } else {
12		                textDescriptHeight = 90;
13	                }
14                    var windowH      = $(window).height()-($('#holyheader').height()+parseInt($("#holycenter").css('margin-top'))+paddingbottom);
15                    var windowW      = $("#holycenter").width();
16                    var theImage     = new Image();
17                    theImage.src     = $image.attr("src");
18                    var imgwidth     = theImage.width;
19                    var imgheight    = theImage.height;
20
21		            //catch bug. Keep running until image is loaded into DOM
22		            if (imgwidth == 0 || imgheight == 0)
23		            {
24			            setTimeout(function() { resize($image);  }, 1000);
25		            }
26
27                    //set a minimum resize size, otherwise it can become negative with the subtraction in "var windowH" above
28                    if (windowH < 100){
29	                	windowH = 100;
30                    }
31                    if (windowW < 100){
32	                	windowW = 100;
33                    }
34
35
36                    if((imgwidth > windowW)||(imgheight > windowH)){
37                        if(imgwidth > imgheight){
38                            var newwidth = windowW;
39                            var ratio = imgwidth / windowW;
40                            var newheight = imgheight / ratio;
41                            theImage.height = newheight;
42                            theImage.width= newwidth;
43                            if(newheight>windowH){
44                                var newnewheight = windowH;
45                                var newratio = newheight/windowH;
46                                var newnewwidth =newwidth/newratio;
47                                theImage.width = newnewwidth;
48                                theImage.height= newnewheight;
49                            }
50                        }
51                        else{
52                            var newheight = windowH;
53                            var ratio = imgheight / windowH;
54                            var newwidth = imgwidth / ratio;
55                            theImage.height = newheight;
56                            theImage.width= newwidth;
57                            if(newwidth>windowW){
58                                var newnewwidth = windowW;
59                                var newratio = newwidth/windowW;
60                                var newnewheight =newheight/newratio;
61                                theImage.height = newnewheight;
62                                theImage.width= newnewwidth;
63                            }
64                        }
65                    }
66                    $image.css({'width':theImage.width+'px','height':theImage.height+'px'});
67                    //Print for testing
68                    //$('.image_title').html('windowW '+windowW+' x imageWidth'+theImage.width);
69}