Was wondering if there's a good site out there for cropping an image like so:
Current size is 336 x 352:
Would like to make it 695 x 395 by combining proper stretching and zooming (so it doesn't look like a distorted stretch)
Imagemagick has a lot of options that can do almost everything.
Related
I am beginning to play with Funvas, and I would like to make a slideshow(only 4 pics, all the same, 1080x1080 size JPG) but giving a pixelated transformation(a bit like example 46 from funvas site) between the appearance of an image to another, holding the image for like 0.5(a half-second) before gets 'destroyed' to assemble another image. What blend image do I need to use?
Using ImageMagick's convert to barrel-distort a photo to correct a strongly visible pincushion distortion, I provide positive a, b or c values (from a database for my lens + focal length). This results in an image that is corrected, has the original width and height, but includes a non-rectangular, bent/distorted border, as the image is corrected towards its center. Simplified example:
convert rose: -virtual-pixel black -distort Barrel '+0.0 +0.1 +0.0' out.png
How can I automatically crop the black, bent border to the largest possible rectangle in the original aspect ratio within the rose?
The ImageMagick website says, that a parameter "d" is automatically calculated, that could do this (resulting in linear distortion effectively zooming into the image and pushing the bent border right outside the image bounds), but the imagemagick-calculated value seems to aim for something different (v6.6.9 on ubuntu 12.04). If I guess and manually specify a "d", I can get the intended result:
convert rose: -virtual-pixel black -distort Barrel '+0.0 +0.1 +0.0 +0.6' out.png
The given formular a+b+c+d=1 does not seem to be a proper d for my cropping case. Also, d seems to depend on the aspect ratio of the image and not only on a/b/c. How do I make ImageMagick crop the image, or, how to I calculate a proper d?
Update
I found Fred's ImageMagick script innercrop (http://www.fmwconcepts.com/imagemagick/innercrop/index.php) that does a bit what I need, but has drawbacks and is no solution for me. It asumes arbitrary outer areas, so it takes long to find the cropping rectangle. It does not work within Unix pipes, and it does not keep the original aspect ratio.
Update 2
Contemplating on the problem makes me think that calculating a "d" is not the solution, as changing d introduces more or less bending and seems to do more than just zoom. The d=1-(a+b+c) that is calculated by imagemagick results in the bent image touching the upper/lower bounds (for landscape images) or the left/right bounds (for portrait images). So I think the proper solution would be to calculate where one of the new 4 corners will be given a/b/c/d, and then crop to those new corners.
The way I understand the docs, you do not use commas to separate the parameters for the barrel-distort operator.
Here is an example image, alongside the output of the two commands you gave:
convert o.png -virtual-pixel black -distort Barrel '+0.0 +0.1 +0.0' out0.png
convert o.png -virtual-pixel black -distort Barrel '+0.0 +0.1 +0.0 +0.6' out1.png
I created the example image in order to better visualize what you possibly want to achieve.
However, I do not see the point you stated about the automatically calculated parameter 'd', and I do not see the effect you stated about using 'd=+0.6'...
I'm not sure I understand your wanted result correctly, so I'm assuming you want the area marked by the yellow rectangle cropped.
The image on the left is out0.png as created by the first command above.
In order to guess the required coordinates, we have to determine the image dimensions first:
identify out0.png
out0.png PNG 700x700 700x700+0+0 8-bit sRGB 36KB 0.000u 0:00.000
The image in the center is marked up with the white rectangle. The rectangle is there so you can look at it and tell me if that is the region you want cropped. The image on the right is the cropped image (without scaling it back to the original size).
Is this what you want? If yes, I can possibly update the answer in order to automatically determine the required coordinates of the cropping. (For now I've done it based on guessing.)
Update
I think you may have mis-understood the purpose of the barrel-distortion operation. It is meant for correcting a barrel (slight) distortion, as is produced by camera lenses. The 3 parameters a, b and c to be used for any specific combination of camera, lens and current zoom could possibly be stated in your photo's EXIF data. The formula were a+b+c+d = 1 is meant to be used when the new, distortion-corrected image should have the same dimensions as the original (distorted) image.
So to imitate the barrel-correction, we should probably use the second image from the last row above as our input:
convert out3.png -virtual-pixel gray -distort barrel '0 -0.2 0' corrected.png
Result:
I am creating a UIImage that I want to print using iOS. The printing type will be
printInfo.outputType = UIPrintInfoOutputGeneral;
or in other words, using regular paper.
As far as I read, iOS will print at 72dpi. So, if I want to print a UIImage with a 2x3 inche size on paper I need to create this image with 144 x 216 points, but how much is it in pixels for that UIImage? or in other words, which size should the image has?
thanks
It looks to me that the 72dpi is actually saying 72 pixels. so your image size of 144 x 216 is actually the size you would want to print. The only reason the UIImageView is measured in points rather than pixels is because of the different screen resolutions. The original iPhone has the same size screen as the 4s, but the screen of the 4s has a LOT more pixels in it. Apple used points so that it is easier to program for all of the devices. Check out this link: http://www.scantips.com/basics1a.html i just read through it and i hope it will answer your question. I apologize if i confused you even more, I'm just trying to help! :)
I created a 8.5x11.0 inches image # a 300dpi setting in photoshop.
When i go to use this as a background image in report designer the image looks hugeee.
It's not fitting within the 8.5x11.0 page.
Is there a way to resize this image correctly so that it will fit correctly within a 8.5x11.0 letter size page?
Thanks in advance,
with the information you gave, i believe your problem is problably in the group Size/dpi
You saved an image of size 8,5 x 11 inches # 300 Dpi (dots per inch) that calculates to aproximately an image of 2550 x 3300 pixels.
Now if your "report designer" software looks only at the size in pixels and assumes a dpi value diferent then the one you used, say for example 72 dpi, your 2550 x 3300 pixels image would actually be something like 45,8 x 35.4 inches.
So, my advice is, find out what are the characteristics your solftware is especting, aparently it is not 300dpi.
If you can´t find the information, try commonly used dpis like 72dpi or 150dpi.
I was given some high-res images, which were originally made for a printed magazine, to show in an iPhone app, like the Xcode PhotoScroller app (like iPhone's native Photo viewer app). I'm down-sizing them to 1024 x 1536 px and I'm going to be slicing them up for use with UIScrollView and CATiledLayer.
When I'm resizing them, should I also convert them from CMYK to RGB?
I think so because RGB is for digital, right? But they also looked fine on the iPhone as CMYK. Why do they say to use RGB for digital?
What's the best way to resize them to 1/2 & 1/4 and slice all 3 sizes up?
1024/4 = 256, so I'm thinking of making every tile (except for the edge ones) 256 x 256 px. I tried Tile Cutter, which worked, but I have 20 images, so I'll have to do it 20 times. Plus, it doesn't let you put levels deep, so I'll also have to resize each image twice in PhotoShop. So, that's 60 images that I'll have to run through The Cutter. It shouldn't take too long, but odds are, I'll be doing this again, so I'd like to have a better solution. Ideally, it'd be cool to do this with the iPhone, but for now, I think I'll use Paul Alexander's Tile Ruby script unless you suggest a better option. I also might try Zoomify.
RGB has a wider range of colors then CMYK.
CMYK is the range of colors printed on a white paper. it stands for Cyan Magenta Yellow and blacK. (think of the 4 colors in your printer cardiges. CMY for colors and K for black.)
when miking CMY you have a very very dark grey. It goes on a scale of 0-100% from each color.
RGB are monitors colors. It's the way LCDs and CRTs process colors. With Red Green and Blue. It goes on a scale of 0-255. 255 of both 3 colors makes white.
Now since monitors are backed with backlight, it can make bright color printers can't do. like shiny green or shiny pink.
A CMYK picture will look fine on screen. A RGB will lose color on print (like those shiny greens will become matte).
For the iPhone, work on RGB. reasons:
- It process directly RGB values
- You'll get precise color
- RGB takes less memory then CMYK