¡@

Home 

2014/10/15 ¤U¤È 10:05:05

iphone Programming Glossary: channel

iOS PNG Image rotated 90 degrees

http://stackoverflow.com/questions/10307521/ios-png-image-rotated-90-degrees

PNG Image rotated 90 degrees In my iOS application I'm writing I deal with PNGs because I deal with the alpha channel. For some reason I can load a PNG into my imageView just fine but when it comes time to either copy the image out of my..

Retrieving a pixel alpha value for a UIImage

http://stackoverflow.com/questions/1042830/retrieving-a-pixel-alpha-value-for-a-uiimage

CGRectMake 0 0 width height image CGContextRelease context I then calculate the array index for the given alpha channel using the coordinates from the UIImageView. int byteIndex bytesPerRow uiViewPoint.y uiViewPoint.x bytesPerPixel unsigned.. get the values I expect. For a completely black transparent area of the image I get non zero values for the alpha channel. Do I need to translate the co ordinates between UIKit and Core Graphics i.e is the y axis inverted Or have I misunderstood..

iOS Image Orientation has Strange Behavior

http://stackoverflow.com/questions/10600613/ios-image-orientation-has-strange-behavior

was okay up until a few days ago. My application modifies individual pixels of an image specifically the alpha channel of a PNG so any JPEG conversion gets thrown out of the window for my scenario . A few days ago I noticed that even though..

Real-time Pitch Shifting on the iPhone

http://stackoverflow.com/questions/1100495/real-time-pitch-shifting-on-the-iphone

How can I change the saturation of an UIImage?

http://stackoverflow.com/questions/1144768/how-can-i-change-the-saturation-of-an-uiimage

context kCGBlendModeSaturation CGContextClipToMask context self.bounds image.CGImage restricts drawing to within alpha channel CGContextSetRGBFillColor context 0.0 0.0 0.0 desaturation CGContextFillRect context rect CGContextRestoreGState context..

iPhone SDK - How to play a video with transparency?

http://stackoverflow.com/questions/1401517/iphone-sdk-how-to-play-a-video-with-transparency

this question You'll need to build a custom player using AVFoundation.framework and then use a video with alpha channel. The AVFoundation framework allows much more robust handeling of video without many of the limitations of MPMedia framework...

color replacement in image for iphone application

http://stackoverflow.com/questions/15082025/color-replacement-in-image-for-iphone-application

to be provided. 5 cvMerge the new image with the new hue with an image composed by the saturation and brightness channels that you saved in step one. i understand that cvMerge will merge three channel of H S and V but how i can use output of.. by the saturation and brightness channels that you saved in step one. i understand that cvMerge will merge three channel of H S and V but how i can use output of above three steps. so basically stuck with opencv implementation if possible then..

How can my server securely authenticate iPhone in-app purchase?

http://stackoverflow.com/questions/1581246/how-can-my-server-securely-authenticate-iphone-in-app-purchase

first get the receipt in the application immediately send it to your server along with the device's UUID over a secure channel such as HTTPS or an SSL socket. Do not store it anywhere leave it in memory. On your server store the UUID and receipt pair.. your server can read the contents by decoding the receipt from base64. Return a response to the device over the secure channel telling it whether the purchase is Authenticated as new wasn't in DB and was valid Authenticated in the past Same UUID and..

Creating a left-arrow button (like UINavigationBar's “back” style) on a UIToolbar

http://stackoverflow.com/questions/227078/creating-a-left-arrow-button-like-uinavigationbars-back-style-on-a-uitoolba

I could manually create it with button images but I can't find the source images anywhere. They have alpha channel edges so screenshotting and cutting won't get very versatile results. Any ideas beyond screenshotting for every size and..

Apple Push Notification Service APNS - Notifications not arriving

http://stackoverflow.com/questions/2293155/apple-push-notification-service-apns-notifications-not-arriving

error socket_close apns fclose apns No connection errors are generated. Nothing seems to be coming from the feedback channel. I got the deviceTokens from the organizer console and an NSLog command. The notifications for this app are showing up in..

iPhone: Changing CGImageAlphaInfo of CGImage

http://stackoverflow.com/questions/2457116/iphone-changing-cgimagealphainfo-of-cgimage

pixel formats definitely does not support this combination. It appears I need to redraw the image and move the alpha channel information to kCGImageAlphaPremultipliedFirst or kCGImageAlphaPremultipliedLast . I have no idea how to go about doing..

How to tint a transparent PNG image in iPhone?

http://stackoverflow.com/questions/3514066/how-to-tint-a-transparent-png-image-in-iphone

context rect myIconImage.CGImage If you don't care for luminosity as you just have got an image with an alpha channel that should be tinted with a color you can do it in a more efficient way draw tint color CGContextSetBlendMode context kCGBlendModeNormal..

Getting RGB pixel data from CGImage

http://stackoverflow.com/questions/6073259/getting-rgb-pixel-data-from-cgimage

a bunch of relevant info about an image as well as a dump of the image's pixel data. It will work on images with alpha channels as well as images without. The code will even work on images that are not in the RGB color space though I doubt you'd be.. printf printf n Here's some sample output on two images I tried. They're both 5x3 rgb. The a.png image has an alpha channel while the b.rgb does not. a.png CGImageGetHeight 5 CGImageGetWidth 3 CGImageGetColorSpace CGColorSpace 0x4d08ff0 kCGColorSpaceDeviceRGB..

How to reverse an audio file?

http://stackoverflow.com/questions/6593118/how-to-reverse-an-audio-file

backwards. I have used CoreAudio to achieve this. Link to app code. As each sample is 16 bits in size 2 bytes mono channel . You can load each sample at a time by copying it into a different buffer by starting at the end of the recording and reading..

Is programmatically inverting the colors of an image possible?

http://stackoverflow.com/questions/6672517/is-programmatically-inverting-the-colors-of-an-image-possible

for int x 0 x width x get RGB values. We're dealing with premultiplied alpha here so we need to divide by the alpha channel if it isn't zero of course to get uninflected RGB. We multiply by 255 to keep precision while still using integers int.. draws the UIImage to it runs through every pixel converting from premultiplied alpha to uninflected RGB inverting each channel separately multiplying by alpha again and storing back gets an image from the context and wraps it into a UIImage cleans..

Write Audio To Disk From IO Unit

http://stackoverflow.com/questions/6930609/write-audio-to-disk-from-io-unit

UInt32 inBusNumber UInt32 inNumberFrames AudioBufferList ioData ref.equnit AudioUnitRender engineDescribtion.channelMixers inBusNumber ioActionFlags inTimeStamp 0 inNumberFrames ioData Engine engine Engine inRefCon AudioUnitRender engineDescribtion.equnit.. CFStringRef destinationFilePath kCFURLPOSIXPathStyle false OSStatus status prepare a 16 bit int file format sample channel count and sample rate AudioStreamBasicDescription dstFormat dstFormat.mSampleRate 44100.0 dstFormat.mFormatID kAudioFormatLinearPCM..

How to manage Enterprise Distribution certificate expiration?

http://stackoverflow.com/questions/9216485/how-to-manage-enterprise-distribution-certificate-expiration

is a month long exercise where we rebuild all our apps and inform all users to get new ones through the distribution channel. Still every year some users are left with non functional apps. I have filed an enhancement request with Apple Bug ID#9848075..

Free Weather API [closed]

http://stackoverflow.com/questions/1305127/free-weather-api

Weather Underground API Example http api.wunderground.com auto wui geo GeoLookupXML index.xml query 90210 Weather Channel Requires signup Example found sample code at github . Ruby gem for accessing the Weather Channel XML API WeatherAPI Norway.. query 90210 Weather Channel Requires signup Example found sample code at github . Ruby gem for accessing the Weather Channel XML API WeatherAPI Norway Example http api.yr.no weatherapi locationforecast 1.6 lat 34 lon 118 share improve this answer..

iPhone “cannot play” .mp4 H.264 video file

http://stackoverflow.com/questions/3285529/iphone-cannot-play-mp4-h-264-video-file

properly and the .mp4 has the following characteristics Dimension 480 272 Codecs AAC H.264 MPEG 4 SDSM MPEG 4 ODSM Channel Count 2 Total Bitrate 991 Size 11.4MB But the problem is when I click on the link iPhone says Movie cannot be played. and..

Accessing iPhone WiFi Information via SDK

http://stackoverflow.com/questions/351954/accessing-iphone-wifi-information-via-sdk

WiFi Information via SDK Is there a way using the iPhone SDK to get WiFi information Things like Signal Strength WiFi Channel and SSID are the main things I'm looking for. Only interested in Wifi info not cellular. iphone cocoa touch wifi share..

How to grab YUV formatted video from the camera, display it and process it

http://stackoverflow.com/questions/4205191/how-to-grab-yuv-formatted-video-from-the-camera-display-it-and-process-it

to capture in kCVPixelFormatType_420YpCbCr8BiPlanarFullRange format for easier processing I need to process the Y Channel . how do I display data in this format I suppose I need to somehow convert it to a UIImage and then put it in some ImageView..

Which weather data web services do you know?

http://stackoverflow.com/questions/8446360/which-weather-data-web-services-do-you-know

Broadcasting Corporation NRK Free weather data. Couldn't figure out what's covered. Language Norwegian. The Weather Channel API weather.com XML or JSON. You're not required to place a logo or cite them. Not free. About 120 per month for about 125k..