How do you create a fixed size (height / width) of images/thumbnails In GD?
I know there is a lot of php scripts out there but that just scale it and height/width will always be different size.
I like the thumbnail like twitpic.com and facebook
You need to get the height and width of the image using getimagesize
and then resize it using imagecopyresized
The rest is all the same basic work done with GD to load and save the image.
Here's a basic example, if you want to take into account height/width ratios, then you have to do some additional maths.
<?php
header("Content-type: image/png");
$size = getimagesize($filename);
$image = imagecreatefrompng($filename);
$thumbnail = imagecreate(100,100);
imagecopyresized($thumbnail, $image, 0, 0, 0, 0, 100, 100, $size[0], $size[1]);
imagepng($thumbnail);
imagedestroy($image);
imagedestroy($thumbnail);
It's easy with Thumbnailer:
$th=new Thumbnailer("your-photo.jpg");
$th->thumbSquare(100)->save("thumb.jpg");
Related
I have a jpg on my server. I use
imagecreatefromjpeg($imgPath);
to open it. I want to make it a 16x9 image by adding black bars to either the top+bottom or left+right. (Think background-size: contain; background-position: center;) This is all I have:
$img_info = getimagesize($imgPath);
I know I need to use ImageCreateTrueColor to make the blank image, imagecopyresampled to create the image, and imagejpeg to save it. But I have no idea how to put them together. Thanks!
This will do the trick:
$im=imagecreatefromjpeg ($imgPath);
$width=ImageSX($im); $height=ImageSY($im); $ratio=16/9;
$width_out=$width; $height_out=$height;
if ($height_out*$ratio<$width_out) {$height_out=floor($width_out/$ratio);} else {$width_out=floor($height_out*$ratio);}
$left=round(($width_out-$width)/2);
$top=round(($height_out-$height)/2);
$image_out = imagecreatetruecolor($width_out,$height_out);
$bg_color = ImageColorAllocate ($image_out, 0, 0, 0);
imagefill($image_out,0,0,$bg_color);
imagecopy($image_out, $im, $left, $top, 0, 0, $width,$height);
imagejpeg($image_out);
How it works: you create the $im container, and check for width and height.
After this, the script checks which side is smaller than the other (multiplied / divided by the ratio) and adjust the output size.
Calculate where the original image should be placed (center alignment) by dividing the difference between the original and the output image dimensions by 2.
Copy over the original image at the given position
Output, done.
i have a site where users can upload images, and i have this function to reduce image resolution and preform alot of checks etc, works fine, except this 1 little bug i cant quite seem to figure out
$fixed_width is the width i want to declare as max allowed, but it is allowed to be lower, but for some reason, this if statement always triggers, and the image gets re-sized leaving a black box.
$width_orig = image width
$fixed_width = max allowed width, if higher, resize to that
$image_p = truecolor
$image = the current location of the img
if ($width_orig > $fixed_width) {
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $fixed_width, $fixed_height, $width_orig, $height_orig); // reduce in width / height
} else {
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width_orig, $height_orig, $width_orig, $height_orig); // leave as is
}
So why does it never pass, it resizes no matter what happens ?
The else block in your code does not make any sense. If you will not change the image, why copy-resample it?
Post the rest of your code to we see the way you are getting the original width.
$image_p has fixed width and height. So when you copy something less, it has blank (black) background to fill the rest. Try just using $image instead (else {$image_p = $image})
I have two images. one is a jpg image of a rotated polaroid frame polaroid.jpg. The other is just an ordinary image image.jpg.
I'm trying to rotate the image, and then put it on top of the polaroid-image, and then show the merged images as one jpg-image.
I think I'm pretty close with the following code, but I can't manage to get the transparancy working. The uncovered zone of the rotated image is black instead of transparent. What am I doing wrong? I've added a comment to the lines that are relevant for getting a transparent background for the top-image.
$bg_src = "polaroid.jpg";
$img_src = "image.jpg";
$outputImage = imagecreatefromjpeg($bg_src);
$img = imagecreatefromjpeg($img_src);
// This should create transparent background.
$bgd_color = imagecolorallocatealpha($img, 0, 0, 0, 127);
// This should assign the transparent background to the uncovered zone after rotation
$img = imagerotate($img, 10, $bgd_color);
// This should make sure the alpha transparency gets saved
imagesavealpha($img, true);
$img_x = imagesx($img);
$img_y = imagesy($img);
imagecopymerge($outputImage,$img,156,50,0,0,$img_x,$img_y,100);
header('Content-type: image/jpeg');
imagejpeg($outputImage);
imagedestroy($outputImage);
Figured it out after some heave searching. Turns out to be real simple.
I just changed this line:
imagesavealpha($img, true);
to this:
imagecolortransparent($img,$bgd_color);
yay! :)
I have a png that is a set of white shape on a transparent background. I'm trying to change to color of the shapes while preserving the transparent background. I've been experimenting with the code below which does change the color but results in a black background. I think the imagetruecolortopalette is causing the problem but the color doesn't change if I remove that line.Any suggestions?
<?php
$imgname = "whiteim.png";
$im = imagecreatefrompng ($imgname);
imagetruecolortopalette($im,false, 255);
$index = imagecolorclosest ( $im, 255,255,255 ); // get White COlor
imagecolorset($im,$index,255,0,0); // SET NEW COLOR
$imgname = "result.png";
imagepng($im, $imgname ); // save image as png
imagedestroy($im);
?>
# imagecolortransparent($im, $xxxx); //not sure why this works
I think this work because imagecolortransparent makes the given color (where you placed $xxxx) transparent, in this case $xxxx contains no value. So what is made transparent are all the pixels that contain no color value.
One thing is I couldn't make that working using imagetruecolortopalette either. Not quite sure if you can use the imagefill function in your case (you need to know where to start the fill and it works if you have one area of white), but this is what I've used.
The other thing is that it seems like you need to call imagesavealpha before you save any alpha information to a png image, otherwise it's lost. Hard to tell for me why isn't it a default setting.
All in all, my approach was:
$imgname = "whiteim.png";.
$im = imagecreatefrompng ($imgname);
imagefill($im, 0,0, imagecolorallocate($im, 255,0,0));
$imgname = "result.png";
imagesavealpha($im, True);
imagepng($im, $imgname ); // save image as png
imagedestroy($im);
I am working on improving one of my Facebook apps by allowing the user to upload an image and apply a styled border, or frame to it (i.e. clouds, stars, sky etc). The user chould also be able to save the image, with the border after it has been applied. This explains a little better what I need:
http://zbrowntechnology.info/ImgDisp/imgdisp.php
If you have any other questions or need more details, please let me know.. I'll edit this post.
Use imagecopy(). The example on that page is done using the transparency option with imagecopymerge() but I don't think you need that.
Using imagecopy() you'll specify the X/Y coordinates to use for positioning:
imagecopy( $borderimage, $topimage, 20, 20, 0, 0, $width, $height);
Where $width and $height will be the entire width and height of the top image. You'll want to replace 20 and 20 with the measurement for how much of the border image will be showing around the borders. You will probably have to resize the top image to the exact dimensions you want, or else it might overlap the border a little too far to the right or bottom. (see imagecopyresampled())
Edit:
Here's a rough way to do the whole process (assuming chosenborder.png is the border they chose, and uploadedimage.png is the image they uploaded. If it's a different image type you'll use the corresponding function).
$borderx = 20; // The width of our border
$border = imagecreatefrompng("chosenborder.png");
$topimage = imagecreatefrompng("uploadedimage.png");
$bordersize = getimagesize($border);
$topimagesize = getimagesize($topimage);
/* The new dimensions of topimage. $borderx*2 means we account for
the border on both left and right, top and bottom. */
$newx = $bordersize[0] - ($borderx*2);
$newy = $bordersize[1] - ($borderx*2);
imagecopyresampled( $topimage_scaled, $topimage, 0, 0, 0, 0,
$newx, $newy, $topimagesize[0], $topimagesize[1]);
/* Merge the images */
imagecopy( $border, $topimage_scaled, $borderx, $borderx,
0, 0, $width, $height);
/* Output the image */
imagepng($border, "newimage.png");
/* Free up the memory occupied by the image resources */
imagedestroy($border);
imagedestroy($topimage);
After the user uploads their image, find chosenborder.png and uploadedimage.png, run the above script, then display newimage.png to the user and you're good to go. Just make sure you call imagedestroy() on the temporary image resources or they'll eat up memory.
If you don't want to keep the generated image on your server, you can omit the second argument to imagepng() which will make it send the image information directly as an image to the browser, in which case you'll want to write the correct image HTTP headers.
Client-side solution by using css3:
checkout the css3 property border-image
(dosen't meet the requirement of saving the img with the border)
Server-side solution by merging 2 different images:
<?php
$imgFile = 'img.jpg';
$brdFile = 'brd.jpg';
$img = addBorder($imgFile,$brdFile);
outputImage($img);
function addBorder($imgFile,$brdFile)
{
$img=imagecreatefromjpeg($imgFile);
$brd=imagecreatefromjpeg($brdFile);
$imgSize = getimagesize($imgFile);
$brdSize = getimagesize($brdFile);
//NOTE: the border img MUST be bigger then the src img
$dst_x = ceil(($brdSize[0] - $imgSize[0])/2);
$dst_y = ceil(($brdSize[1] - $imgSize[1])/2);
imagecopymerge ( $brd, $img, $dst_x, $dst_y, 0, 0, $imgSize[0], $imgSize[1] ,100 );
return $brd;
}
function outputImage($img)
{
header('Content-type: image/png');
imagepng($img);
}
?>