IOS app for programmable camera: Difference between revisions
imported>Projects221 |
imported>Projects221 |
||
| Line 11: | Line 11: | ||
==Histogram and histogram equalization == | ==Histogram and histogram equalization == | ||
'''Image Histograms''' | '''Image Histograms:''' | ||
Histograms are graphical representations of tonal and luminance distributions in an image. Inspecting histograms of live preview in a camera can help the photographers to adjust the exposure values of their cameras. Also, the RGB histograms can be used as a guide to selectively adjust exposure for different colors. You can make sure that you are not losing details by underexposing or overexposing certain colors. That's why we incorporated the live histogram feature into our app. | Histograms are graphical representations of tonal and luminance distributions in an image. Inspecting histograms of live preview in a camera can help the photographers to adjust the exposure values of their cameras. Also, the RGB histograms can be used as a guide to selectively adjust exposure for different colors. You can make sure that you are not losing details by underexposing or overexposing certain colors. That's why we incorporated the live histogram feature into our app. | ||
The GPUImage library provides APIs by which histograms of images can be extracted. We used the APIs GPUImageHistogramFilter and GPUImageHistogramGenerator to extract a histogram and plot it. After extracting the histogram image, we blend it into the live preview image using GPU blend filter. The screenshots are attached. | The GPUImage library provides APIs by which histograms of images can be extracted. We used the APIs GPUImageHistogramFilter and GPUImageHistogramGenerator to extract a histogram and plot it. After extracting the histogram image, we blend it into the live preview image using GPU blend filter. The screenshots are attached. | ||
| Line 17: | Line 17: | ||
'''Histogram equalization and histogram matching:''' | |||
Equalizing a histogram is a technique that is used to adjust pixel intensities to enhance contrast. It's a transformation by which the image pixel intensities (often ranging from 0 - 256) are normalized and redistributed. | Equalizing a histogram is a technique that is used to adjust pixel intensities to enhance contrast. It's a transformation by which the image pixel intensities (often ranging from 0 - 256) are normalized and redistributed. | ||
In a grayscale image or a monotone image, this redistribution is a simple operation of redistribution | In a grayscale image or a monotone image, this redistribution is a simple operation of redistribution | ||
Revision as of 23:32, 20 March 2014
Introduction
Programmable cameras
Our Project
Methodology
Filters using GPUImage library
Histogram and histogram equalization
Image Histograms: Histograms are graphical representations of tonal and luminance distributions in an image. Inspecting histograms of live preview in a camera can help the photographers to adjust the exposure values of their cameras. Also, the RGB histograms can be used as a guide to selectively adjust exposure for different colors. You can make sure that you are not losing details by underexposing or overexposing certain colors. That's why we incorporated the live histogram feature into our app. The GPUImage library provides APIs by which histograms of images can be extracted. We used the APIs GPUImageHistogramFilter and GPUImageHistogramGenerator to extract a histogram and plot it. After extracting the histogram image, we blend it into the live preview image using GPU blend filter. The screenshots are attached.
Histogram equalization and histogram matching: Equalizing a histogram is a technique that is used to adjust pixel intensities to enhance contrast. It's a transformation by which the image pixel intensities (often ranging from 0 - 256) are normalized and redistributed. In a grayscale image or a monotone image, this redistribution is a simple operation of redistribution