I would like to change the color of an image with php.
if I wanted to make it appear redder applicherei an image on a higher level across an image with a transparent red and more or less high can indicate how the original photo should be red.
I can say gd php functions to create an image of a color (RGBA) and apply it to another image?
thanks :)
You can try using GD's imagecopymerge function, which copies one image to another and supports alpha transparency. Something like this should work:
<?php
$redimg = imagecreatetruecolor(100, 100);
$image = imagecreatefrompng('image.png');
// sets background to red
$red = imagecolorallocate($redimg, 255, 0, 0);
imagefill($redimg, 0, 0, $red);
// Merge the red image onto the PNG image
imagecopymerge($image, $redimg, 0, 0, 0, 0, 100, 100, 75);
header('Content-type: image/png');
imagepng($image);
imagedestroy($image);
imagedestroy($redimg);
?>
There's more information here.
Related
I have successfully merged a png image to a jpeg background using the php GD library however I would like the png image to have a transparent background yet a white background is constantly displayed as shown below:
I have looked at a few posts to fix this issue and tried different methods of implementation all in vain, any suggestions as to what I should add or do?
Here is my code:
<?php
$background = imagecreatefromjpeg('img3.jpg');
$bird = imagecreatefrompng('img4.png');
$bird_x = imagesx($bird);
$bird_y = imagesy($bird);
imagesavealpha($bird, true);
$color = imagecolorallocatealpha($bird, 0, 0, 0, 127);
imagefill($bird, 0, 0, $color);
if (imagecopymerge($background, $bird, 0, 0, 0, 0, $bird_x, $bird_y, 100))
{
header('Content-Type: image/jpeg');
imagejpeg($background);
imagedestroy($bird);
}
else
{
header('Content-Type: text/html');
echo "Failed to Merge images!";
}
?>
Use imagecopy
imagecopy($dest_image, $src, ($offset + 250), $offset, 0, 0, imagesx($src),imagesy($src));
I guess the specified behavior is by design.
imagecopymerge merges N% of pixels of the source image with (100-N)% of pixels from the destination image. From this definition it would be logical to assume that you won't see any of the background image pixels in the area where you've copied the bird (which is the full rectangle). Hence the white pixels instead of alpha.
Try imagecopy or imagecopyresampled (example) without resizing.
In css, we have a property called "z-index", what is the same in PHP GD and Image Functions to control the "z-index"?
I've been searching but I can't find one, please help.
Thankyou
there nothing existing like z-index in php GD library
but there several ways to overlap image over image or text over image
$redimg = imagecreatetruecolor(100, 100);
$image = imagecreatefrompng('image.png');
// sets background to red
$red = imagecolorallocate($redimg, 255, 0, 0);
imagefill($redimg, 0, 0, $red);
// Merge the red image onto the PNG image
imagecopymerge($image, $redimg, 0, 0, 0, 0, 100, 100, 75);
header('Content-type: image/png');
imagepng($image);
imagedestroy($image);
imagedestroy($redimg);
here one example, or let me know, what exactly you trying to do, I will help you
There's more information here.
I want to do the following in PHP in combination with GD. ImageMagick is not an option, unfortunately, but this seems like such a common problem that there has to be a solution, I just can't seem to find it.
I want to create a PNG with a transparent background. Then I want to draw a rectangle on it, copy an image on it, and add some text. One way of doing this is as follows:
$image = ImageCreateTrueColor (800, 600);
imagecolortransparent ($image, 0); //0 is pure black, the default fill color
imagerectangle (...);
//code to copy an image
imagettftext ($image, ...);
imagepng ($image);
This works fine, except that part of the copied image might be black, and/or the text might be black. This then also becomes transparent, which is something I don't want.
imagefill ($image, 0,0, 0x7FFF0000);
imagetransparent ($image, 0x7FFF0000);
The above code is something I found online, which fills it with red, then makes red transparent. Again, this causes all red in the image to become transparent. I could choose a color that is unlikely to occur, but I can't guarantee this.
Is there something I'm missing? Can this be fixed?
Thanks for your replies!
imagecolortransparent is probably not what you want here if you're merging images, as single-colour transparency is nasty.
Instead, try it with a transparent fill mask like so:
<?php
$image = imagecreatetruecolor(100, 100);
// Transparent Background
imagealphablending($image, false);
$transparency = imagecolorallocatealpha($image, 0, 0, 0, 127);
imagefill($image, 0, 0, $transparency);
imagesavealpha($image, true);
// Drawing over
$black = imagecolorallocate($image, 0, 0, 0);
imagefilledrectangle($image, 25, 25, 75, 75, $black);
header('Content-Type: image/png');
imagepng($image);
I need to create a PNG image from 4 parts of another PNG image with different levels of transparency using GD library in PHP. For example:
Result should look like this
I tried to do this thing in different ways but I coudn't achieve the desired result.
Thank you in advance ;)
Load your image with imagecreatefrompng(). Create a truecolor image with imagecreatetruecolor() and then set it fully transparent with imagecolorallocatealpha() and imagefill(). Then set alpha blending mode for both the source and destination images with imagealphablending(). After this you can use imagecopymerge() to copy the image with alpha.
Unfortunately it's not possible to enforce an alpha multiplier for imagecopymerge(), so this will get you only halfway there -- Inconvenient options include repeating imagecopymerge() calls on those parts of the image you want to be less transparent, choosing between several source images depending on the level of transparency you want to use, or going through the image pixel-by-pixel, which is inconveniently slow.
If you are not married to the image* functions, consider using ImageMagick instead. It is much more robust.
I did this:
$output = imagecreatetruecolor([width], [height]);
imagesavealpha($output , true);
$trans_colour = imagecolorallocatealpha($output , 0, 0, 0, 127);
imagefill($output , 0, 0, $trans_colour);
Now the image is transparent :)
The whole script:
$output = imagecreatetruecolor([width], [height]);
imagesavealpha($output , true);
$trans_colour = imagecolorallocatealpha($output , 0, 0, 0, 127);
imagefill($output , 0, 0, $trans_colour);
header('Content-Type: image/png');
imagepng($output);
imagedestroy($output);
Hope it helps!
This worked for me with both gif and png (of course, change every reference of png in this example to gif if using that image type).
$virtual_image = imagecreatetruecolor($desired_width, $desired_height);
$colour = imagecolorallocate($virtual_image,255,255,255);
imagefill($virtual_image , 0, 0, $colour);
imagealphablending($virtual_image,true);
imagesavealpha($virtual_image , true);
//the next line only if you're resizing to a new $width/$height, otherwise leave this line out
imagecopyresampled($virtual_image, $source_image, 0, 0, 0, 0, $desired_width, $desired_height, $width, $height);
header('Content-Type: image/png');
if (imagepng($virtual_image)) imagedestroy($virtual_image);
i'm working on creating one PNG image from two others.
Image A and B have the same dimensions, they are both 200x400px. The final image the same.
I'm using the GD library with PHP.
So my idea was to create a PNG-24 from my original PNG-8, then use color transparency and finally copy the second image into
this new PNG-24. The problem appears in the first step anyway, when going from PNG-24 to PNG-8 with color transparency:
This is to get the original PNG-8 and it's dimensions:
$png8 = imagecreatefrompng($imageUrl);
$size = getimagesize($imageUrl);
Now i create a new PNG and fill it's background with a green color (not present in the images):
$png24 = imagecreatetruecolor($size[0], $size[1]);
$transparentIndex = imagecolorallocate($png24, 0x66, 0xff, 0x66);
imagefill($png24, 0, 0, $transparentIndex);
This is for making the green color transparent:
imagecolortransparent($png24, $transparentIndex);
Then i copy the png8 into the PNG-24:
imagecopy($png24, $png8, 0, 0, 0, 0, $size[0], $size[1]);
So here's the problem: the original PNG-8 looks good, but it has a green border surrounding the shape within the original image. It's difficult to explain really. Seems like some part of the green background is left in the remaining PNG.
What can i do?
thanks in advance
best regards,
Fernando
I had some problems with png transparency before and was able to solve them with this pattern:
// allocate original image to copy stuff to
$img = imagecreatetruecolor(200, 100);
// create second image
$bg = imagecreatefrompng('bg.png');
// copy image onto it using imagecopyresampled
imagecopyresampled($img, $bg, 0, 0, 0, 0, 200, 100, 200, 100);
imagedestroy($bg);
// create third image
// do same routine
$fg = imagecreatefrompng('fg.png');
imagecopyresampled($img, $fg, 50, 50, 0, 0, 50, 50, 50, 50);
imagedestroy($fg);
// output image
imagepng($img);
imagedestroy($img);
I think the only difference between mine and yours is imagecopy() vs. imagecopyresampled(). I seem to remember having problems with that though it was quite a while ago. You can see an example of an image I use this pattern on here: http://www.ipnow.org/images/1/bggrad/bg4/yes/TRANSIST.TTF/8B0000/custombrowserimage.jpg (I allocate a blank image, copy the background image in, copy the overlay with transparency in)