image_analysis.h

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/*
 * Copyright 2014 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http:///www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


#ifndef PAGESPEED_KERNEL_IMAGE_IMAGE_ANALYSIS_H_
#define PAGESPEED_KERNEL_IMAGE_IMAGE_ANALYSIS_H_

#include <cstddef>
#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/image/image_util.h"

namespace net_instaweb {
class MessageHandler;
}

namespace pagespeed {

namespace image_compression {

class ScanlineReaderInterface;
using net_instaweb::MessageHandler;

const int kNumColorHistogramBins = 256;

bool SobelGradient(const uint8_t* image, int width, int height,
                   int bytes_per_line, PixelFormat pixel_format,
                   MessageHandler* handler, uint8_t* gradient);

void Histogram(const uint8_t* image, int width, int height, int bytes_per_line,
               int x0, int y0, float* hist);

float PhotoMetric(const uint8_t* image, int width, int height,
                  int bytes_per_line, PixelFormat pixel_format, float threshold,
                  MessageHandler* handler);

float WidestPeakWidth(const float* hist, float threshold);

bool IsPhoto(ScanlineReaderInterface* reader, MessageHandler* handler);

bool AnalyzeImage(ImageFormat image_type,
                  const void* image_buffer,
                  size_t buffer_length,
                  int* width,
                  int* height,
                  bool* is_progressive,
                  bool* is_animated,
                  bool* has_transparency,
                  bool* is_photo,
                  int* quality,
                  ScanlineReaderInterface** reader,
                  MessageHandler* handler);

}  

}  

#endif