I obtain seven thumbnail images from my one PDF melodramatically, and these seven images are stored in one array as objects. Now i want to show the images in the array in a UIWebView, but it is not possible because the web view needs a path to a resource or a plist path. So I want to store these images in a plist; how can I do this?
In my array, only the image objects are available, not the names, and all seven images are not static images.
I am new in iPhone programming, so please tell me how I can do this?
Your question does not make much sense to me (melodramatically?). Contrary to what you believe, UIWebView cannot deal with a property list. What would it be supposed to do with it? A web view can display data from a URL request, a string of HTML or a bunch of data in a specified format.
In your case, the latter would apply: convert one of your images into an NSData object (with UIImagePNGRepresentation()) and pass it to the web view with -loadData:MIMEType:textEncodingName:baseURL:.
If you want to display all images at once, you would have to save the images to disk and generate appropriate HTML code.
Related
I want to store the text in image.
I want to store text inside the image.
Is this possible? For example, the image contains various information such as location information.
I like to store my text inside the images like them.
I want to store the string inside the data of the image rather than the visual.
For example, you might want to store a small string that identifies the image in the image, so you want to separate it when you import the image.
I want to implement it in swift.
Your Q still leaks of information, what you really want to do. But I'll try to give you an answer, which might be a step to a better Q.
If you are talking about "inside" the image, you might mean inside the pixel data itself. It is possible to add data to an image without changing the image for humans. This is called a digital watermark or fingerprint. Typically this is used for DRM. You will find some information about this by using a search machine like Qwant.
But I do not think, that you really want to do this. Likely you want to add information in an image file. First of all you need a file format supporting additional data. Tiff is an example. AFAIK there is no build-in facility to get partial TIFF data for the image with ability to add private tasks. You have to create the file your own.
I am newly in iOS development.I have to make an application for a car dealer in which i have to show different cars with different colors.Please tell me the best way because i have to fetch lots of images every time from the web server.How can i reduce the rendering time in fetching the images.
Please consider i am very new in ios development and need your help.
If you have any sample application please share it with me.
You can use DB to store images as BLOB and also fetch images only when there is update at server.
First, make sure you send images that are no larger than needed.
If you have a list view that shows pictures of the cars, have a webservice send you premade thumbnails that are (preferably) exactly the right size.
Second, Make sure the images are loaded separately from the data set.
The best place to do this, would be in the controllers for your UITableViewCell.
Just have your UITableViewCell start their own thread to download and display the image as soon as they come into view.
Third; caching.
Make sure you save local copies of the thumbnails, and make sure the Table View Cells search for local copies of the images, and load those instead of downloading them if they are already locally present.
you can do:-
use lazy loading
use paging
use predicates for searches
use fast enumeration
these things in general will keep your app smooth
If you are going to show images in UITableView then you can use lazy loading. It will load images only for the displayed rows and once image for any row index has been downloaded, it will not repeat downloading for that row index. So its faster and useful.
For example, I can convert the second image into NSData and then place it inside metadata inside the first image and then when I open the first image and read the metadata I can get the NSData and turn it into an UIImage.
How would I go about doing this? All the metadata tags I see are not large enough to support another picture. I know picture in picture is quite common on desktop apps so I'm interested in getting it to work on the iPhone.
Is metadata the correct way to do this or is there another way?
I have a PDF reader that displays pages of the document. What I want to do is allow the user to draw over the PDF in a transparent view. Then I want to save the drawing (UIImage) to disk. If at all possible, I don't want to have the documents folder filled with files like documentName_page01.png, documentName_page02.png for every page that is drawn over.
However, I can't figure out how to store these UIImages into a single file without it becoming unwieldy and memory intensive.
Any ideas appreciated.
What is the user drawing, just lines, rectangles, circles and so on? Maybe store colors and paths of what needs to be drawn, put all of that into an NSArray and serialise that. That might be easier than trying to put multiple UIImages into a file, will use up less space on the device, and might be faster to load. Then just recreate the drawings.
Use Core Data to store your images in Binary Data fields and retrieve them from there. This way, you won't fill your Documents folder with images, no matter how many PDFs of how many pages you have. Here's a tutorial showing you how to do this.
Is it possible, in an iPhone app, to extract location information (geocode, I suppose it's called) from a photo taken with the iPhone camera?
If there is no API call to do it, is there any known way to parse the bytes of data to extract the information? Something I can roll on my own?
Unfortunately no.
The problem is thus;
A jpeg file consists of several parts. For this question the ones we are interested in are the image data and the exif data. The image data is the picture and the exif data are where things like geocoding, shutter speed, camera type and so on are stored.
A UIImage (and CGImage) only contain image data, no tags.
When the image picker selects an image (either from the library or the camera) it returns a UIImage, not a jpeg. This UIImage is created from the jpeg image data, but the exif data in the jpeg is discarded.
This means this data is not in the UIImage at all and thus is not accessible.
I think the selected answer is wrong, actually. Well, not wrong. Everything it said is correct, but there is a way around that limitation.
UIImagePickerController passes a dictionary along with the UIImage it returns. One of the keys is UIImagePickerControllerMediaURL which is "the filesystem URL for the movie". However, as noted here in newer iOS versions it returns a url for images as well. Couple that with the exif library mentioned by #Jasper and you might be able to pull geotags out of photos.
I haven't tried this method, but as #tomtaylor mentioned, this has to be possible somehow, as there are a few apps that do it. (e.g. Lab).