Hey all i am trying to figure out how to resize an image that has a higher height than width. The normal width and height of the area where the image needs to be displayed is:
width = 1000px
height = 700px
What type of math would i need in order to resize that to the proper width/height above without screwing it?
The test image size is:
width = 1451
height = 2200
I was thinking of doing this:
(700/org.height)
But that does not come up with the correct number of 462.
In photoshop, changing the height to 700 yields a width value of 462.
so you want to scale your image so that it fits as large as possible within a 1000x700 square without stretching it? You could do something like this:
$availH = 700;
$availW = 1000;
$imageH = 2200;
$imageW = 1451;
// you know you want to limit the height to 700
$newH = $availH;
// figure out what the ratio was that you adjusted (will equal aprox 0.3181)
$ratio = $availH / $imageH;
// now that you have the $ratio you can apply that to the width (will equal 462)
$newW = round(imageW * $ratio);
Now you have $newW and $newH which are the new sizes for your image properly scaled. You could of course condense this down but I've written it out so each step is more clear.
Formula to keep aspect ratio when resizing is
original height / original width x new width = new height
Source: http://andrew.hedges.name/experiments/aspect_ratio/
But you want to switch it around to the following I think:
original width / original height x new height = new width
Related
I have 2 dimensions, (width & height) and I need to take another image, and resize it until both width and height are greater than the 2 dimensions. If the image is already larger than the 2 dimensions, I still need to resize it to be slightly larger than the given dimensions.
I also need to keep the image aspect ratio the same.
I've been trying the following:
$masksize = getimagesize($maskpath);
// Reverse the sizes as it's landscape and we're always checking portrait
$maskwidth = $masksize[1];
$maskheight = $masksize[0];
$currentsize = getimagesize($target_path);
$currentwidth = $currentsize[0];
$currentheight = $currentsize[1];
$thumwidth = 0;
$thumbheight = 0;
do {
$thumbwidth += 10;
$thumbheight = $currentheight*($thumbheight+10/$thumbwidth);
}while (($thumbwidth < $maskwidth) && ($thumbheight < $maskheight));
However it's not working, it only loops once and the width stays at 10.
So say for instance I have an image at 1000 x 2000, and the dimensions I have are 500 x 1000, I need the image to be resized to 510 x 1010 (i.e always bigger than the given dimensions, but only by a max of 10)
I know how to resize an image keeping its ratio based on these formulas :
Width Formula :
Orig H / Orig W * New W = New H
Height Forula :
Orig W / Orig H * New H = New W
But i have set a maximum width before the image is resized and a maximum height value too.
So how do i work it with two maximum values ??
Say the max height was 600 and the max height was 100 ??
The answer is probably staring me in the face..
This is what i have just now using just the height.
$image_size = new Image(DIR_IMAGE.'data/signatures/'.$file);
$w_size = $image_size->info['width'];
$h_size = $image_size->info['height'];
$w_new_size = round($w_size/$h_size*100);
$h_new_size = 100;
I guess what i'm trying to say is i don't want the image to go above the set width or set height but it has to keep its ratio.
Some show me the light ??
Let php.net show you the light:
http://www.php.net/manual/en/function.imagecopyresampled.php
Example #2 is doing what you ask for, isn't it?
I just want to know if it is possible to get different images' sizes, and create fixed thumbnail dimension measurements for these pictures without losing their accurate aspect ratios.
So far, I have made these:
Resize different images
Maintain their aspect ratios
NOT supplying the same size (for example: 100px- height and 100px- width)
Here's the code that I am working with:
<?php
require("dbinfo.php");
$allPhotosQuery = mysql_query (" SELECT * FROM `placesImages` ");
while ($allPhotosArray = mysql_fetch_assoc ($allPhotosQuery))
{
$filename= $allPhotosArray['fileName'];
$placeId = $allPhotosArray['placeId'];
$imagePath = "placesImages/" . $placeId . "/" . $filename;
$imageSize = getimagesize($imagePath);
$imageWidth = $imageSize[0];
$imageHeight = $imageSize[1];
$newSize = ($imageWidth + $imageHeight)/($imageWidth*($imageHeight/45));
$newHeight = $imageHeight * $newSize;
$newWidth = $imageWidth * $newSize;
echo "<img src='".$imagePath."' width='".$newWidth."' height='".$newHeight."' />";
}
?>
Short of cropping, the simplest way to maintain aspect ratio while making a thumbnail is to do something similar to what you have, but set one fixed:
For example, if you want all your tumbs to be 100px wide:
$imageWidth = $imageSize[0];
$imageHeight = $imageSize[1];
$ratio=ImageWidth/$imageHeight;
$newHeight=(int)$ratio*100;
$newWidth=100;
The caveat with this is that you might end up with some funny sizes if the image has a funny ratio - as in it will happily go ahead and just do it. It might be a good idea to put some sort of check on the ratio in your code - if it it too low or too high, do something else, otherwise use this standard process.
feed this function your original image width and heights followed by the maximum constraints of your thumbnail limits and it will spit out an array with x/y of what you should set your thumbnail at to maintain aspect ratio. (anything smaller than the thumbnail will be enlarged)
function imageResizeDimensions($source_width,$source_height,$thumb_width,$thumb_height)
{
$source_ratio = $source_width / $source_height;
$thumb_ratio = $thumb_width / $thumb_height;
if($thumb_ratio > $source_ratio)
{
return array('x'=>$thumb_height * $source_ratio,'y'=>$thumb_height);
}
elseif($thumb_ratio < $source_ratio)
{
return array('x'=>$thumb_width,'y'=>$thumb_width/$source_ratio);
}
else
{
return array('x'=>$thumb_width,'y'=>$thumb_width);
}
}
Let’s begin with two constants, thumb_width and thumb_height, which are the desired width and height of your thumbnail images. They can be equal, but don’t have to be.
If you have an image that’s wider than it is tall (landscape) we can set the width to the desired width of the thumbnail, thumb_width, and adjust the height to maintain the aspect ratio.
new_width = thumb_width
new_height = thumb_height * old_height / old_width
See imagecreatetruecolor.
Then you can move the image to center it vertically within the limits of the thumbnail, producing a letterbox effect. See imagecopyresampled.
new_y = (thumb_height - new_height) / 2
For images that are taller than they are wide (portrait) the procedure is the same, but the math is a little different.
new_height = thumb_height
new_width = thumb_width * old_width / old_height
Then you can center it horizontally within the limits of the thumbnail.
new_x = (thumb_width - new_width) / 2
For more information on the basics of creating thumbnail images see Resizing images in PHP with GD and Imagick
I would like manipulate/resize images in a similar way to Pinterest but I am not sure what is the best way to approach it. The goal is to allow a mix of both portrait and landscape images but put some restrictions on the maximum height and width.
The problem i can see is that if I resize to a width, a portrait image may become too thin, and the opposite it true for a landscape image.
Any ideas on how to achieve those sort of results with PHP?
You just need to understand which of the two edges of the image is longer, and compute the other dimension proportionally. If the maximum long-egde is 1024, then if one of the two edges is larger you will set that to 1024, and compute the other to fit the proportions. Then you will pass those two values to your image management functions.
Like here:
http://www.white-hat-web-design.co.uk/blog/resizing-images-with-php/
Or here:
http://www.9lessons.info/2009/03/upload-and-resize-image-with-php.html
try with this
$needheight = 1000;
$needwidth = 1000;
$arrtest = getimagesize($upload_image_physical_path);
$actualwidth = $arrtest[0];
$actualheight = $arrtest[1];
if($needwidth > $actualwidth || $needheight > $actualheight){
//uplaod code
}
cheers
Check for a max size and then resize based on a ratio. Here's a pseudo code example:
if($imageHeight > $maxHeight) {
$newHeight = $maxHeight;
$newWidth = $imageWidth * ($maxHeight / $imageHeight);
}
if($imageWidth > $maxWidth) {
$newWidth = $maxWidth;
$newHeight = $imageHeight * ($maxWidth / $imageWidth);
}
resize($image, $newWidth, $newHeight);
It first checks the height and if the height is greater, it scales it down. Then it checks the width. If the width is too big, it scales it down again. The end result, both height and width will be with in your bounds. It uses the ratio to do the scaling.
Note, this is pseudocodish. The actual resize function call will depend on your image manipulation library -- same goes for calls to obtain image size.
I am trying to find a way to calculate an image width/height ratio
to resize it and keep the proportions.
For example, I want to resize a 500x750 image and reduce its width to 350. What height should I use that is proportional to 350?
Use Javascript.
See this tutorial:
http://www.ajaxblender.com/howto-resize-image-proportionally-using-javascript.html
Using the function the other guy posted:
<?PHP
$imagePath = "images/your_image.png";
list($oldWidth, $height, $type, $attr) = getimagesize($image_path);
$percentChange = $newWidth / $oldWidth;
$newHeight = round( ( $percentChange *$height ) );
echo '<img src="'.$imagePath.'" height="'.$new_height.'" width="'.$newWidth.'">';
?>
I think this is the php function you're looking for: getimagesize
From the manual:
Returns an array with 7 elements.
Index 0 and 1 contains respectively the width and the height of the
image.
Here's a short example how to work with this for your problem:
// get the current size of your image
$data = getimagesize('link/your/image.jpg');
// your defined width
$new_width = 350;
// calculate the ratio
$ratio = $data[0] / $new_width;
// apply the ratio to get the new height of your image
$new_height = round($data[1] / $ratio);
...done!
use getImagesize and get the new height by dividing by the aspect ratio.
list($width, $height, $type, $attr) = getimagesize("image.jpg");
$aspect = $width / $height;
$newWidth = 350;
$newHeight = $newWidth / $aspect;
You tagged your question with the PHP tag, so assuming you want to use PHP:
To get an image's height or width from an image resource, use imagesx() and imagesy(). http://www.php.net/manual/en/function.imagesx.php
http://www.php.net/manual/en/function.imagesy.php
To get an image's height and width from an image file, use getimagesize(). Items 0 and 1 in the array returned by that function are the width and height of the image.
http://www.php.net/manual/en/function.getimagesize.php
If you have an image that is 500 pixels wide and 750 pixels high, and you have a container that is 350 pixels wide, you can calculate the ratio by dividing the desired width by the actual width: 350/500 which is 0.7. So to calculate the height, multiply it by that ratio (750 * 0.7 or 525).